Immunology Exam Ii

Front 1

Hypersensitivity

Back 1

-Normal immune response that is pathological
-A state of reactivity to an aintgen that is greater than normal
--Dangerous rather than protective outcome
-Requires an initial exposure before second over-response exposure

Front 2

Types of hypersensitivity

Back 2

-Originally I, II, III, IV
-Can be antibody dependent vs. independent
-IgE vs. IgG
-Antibody bound to cells vs. antibody bound to antigen
-Immediate vs. delayed

Front 3

Type I hypersensitivity

Back 3

-IgE triggers mast cell mediators
-Antigen is allergen
-Onset in minutes
-Antibody-mediated
-Ex: bee sting

Front 4

Type II hypersensitivity

Back 4

-IgG or IgM binds to cell surface
--Antigen-deendent cytocellular toxicity
-Antigen is cell surface molecules, your own surface molecules
-Onset is a few hours
-Antibody-mediated

Front 5

Type III hypersensitivity

Back 5

-Mechanism is immune complexes or inflammation
-Under certain circumstances, there are so many antibodies present that they complex in the serum
--precipitate out of serum
--Tend to land on tissues, trigger activity of other cell types
-Antigen is soluble or particulate
-Antibody-mediated
-Onset is a few hours

Front 6

Type IV immune response

Back 6

-T-cell mediated
-Cytokines initiate response
-Antigen is chemicals
-Onset is 1-3 days

Front 7

Immediate hypersensitivity

Back 7

-Type I hypersensitivity
-Happens within seconds to minutes
-Commonly referred to as an allergy
-Immediate reaction to something in the environment
-Manifestation depends on side of exposure to allergen

Front 8

Type I hypersensitivity diagnosis

Back 8

-Skin test vi intrademal injection of allergens
-If individual is allergic to the injected substance, local cells degranualte and produce response within minutes
-Drawbacks:
--Sometimes sensitized individuals can have anaphylactic rxn to skin test
--Sensitizes an individual to new allergens
--Some individuals may have late-phase reaction 4-6 hours later

Front 9

"Wheel and Flare" reaction

Back 9

-reddening and raised reaction

Front 10

Radioallergosorbent Test

Back 10

-test for type I hypersensitivity
-Allergen is bound with patient's IgE
-Add 2nd antibody radiolabeled for IgE
--if IgE gets a signal, means that the radiolabeled antibody bound to IgE that bound to antigen
--there is antibody present in the serum of the individual that reacts to antigen

Front 11

Allergens

Back 11

-Antigens capable of stimulating type I hypersensitivity reactions
-Most humans mount significant IgE responses to parasites ONLY
-In industrialized countries, IgE response to innocuous antigen predominates
-Most allergic IgE responses occur on mucous membranes in response to allergens that are ingested or inhaled
--asthma (humans)
--skin disease (dogs)

Front 12

IgE mediated Systemic Anaphylaxis

Back 12

-Common allergens: drugs, serum, venoms, peanuts
-Enters intravenously directly or through oral absorption into the blood
-Response:
--edema
--increased vascular permeability
--Tracheal occlusion
--Circulatory collapse
--Death

Front 13

IgE mediated Acute Urticaria

Back 13

-"Wheel and flare" response
-Common allergens: insect bites, allergy testing
-Subcutaneous route of entry
-Results in local increase in blood flow and vascular permeability

Front 14

IgE mediated allergic Rhinitis

Back 14

-"Hay Fever"
-Common allergens: rag weed, timothy, birch, dust-mite feces
-Enters body via inhalation
-Results in edema of nasal mucosa and irritation of nasal mucosa

Front 15

IgE mediated Asthma

Back 15

-Common Allergens: danders (cat), pollens, dist-mite feces
-Enters body via inhalation
-Results in bronchial constriction, increased mucus production, and airway inflammation

Front 16

IgE-mediated Food Allergy

Back 16

-Common allerges: tree nuts, peanuts, shellfish, eggs, fish, milk
-Oral intake route of entry
-Results in vomiting, diarrhea, puritis (itching), urticaria (hives), and rarely anaphylaxis

Front 17

Asthma

Back 17

-Type I hypersensitivity
-Can be debilitating
-Results in chronic obstructive disease of the lower airways
--characterized by episodic events that limit airflow
-Inflamed airways react to environmental triggers
--smoke, dust, pollen
--augmented responsiveness to stimuli
-Airway narrows and produces excess mucus
--individual cannot breathe
-Reversible obstructions

Front 18

Allergic Conditions

Back 18

-Milk and food allergy
-Allergies to vaccinations and drugs
-Allergies to parasites
--insect bites
-30% of skin diseases in dogs are due to allergic dermatitis
--usually flea bites

Front 19

Anaphylaxis

Back 19

-Rapid, systemic, severe type I hypersensitivity reaction

Front 20

Anaphylactic Shock

Back 20

-Most severe type of anaphylaxis
-Occurs when an allergic response triggers a quick release from mast cells of large quantities of mediators
--histamine, prostaglandins, leukotrienes
-Leads to systemic vasodilation
-Usually associated with a sudden drop in blood pressure

Front 21

Species with respiratory anaphylaxis

Back 21

Ruminants
Swine
Equine
Feline
Human

Front 22

Dog response to anaphylaxis

Back 22

-Hepatic vein response
-Show initial excitement
--followed by vomiting, defecation, urination
-Progressive signs with muscular weakness, depressed respiration
-Pt will become comatose, convulsive
-Can die within an hour

Front 23

Phases of Type I hypersensitivity

Back 23

1. Sensitization: primary exposure
2. Activation: second exposure
3. Effector phase: any subsequent response

Front 24

TH-2 cells and allergies

Back 24

-Mediators of allergy
-Protect against helminths
-Regulate immunity
-Switches B-cell IgM production to IgE production

Front 25

Sensitization phase of type I hypersensitivity

Back 25

-TH2 cell stimulates B-cell IgE production
-CD40-ligand and CD40 play important role
--produce cytokines and switch B-cell from IgM production to IgE production (class switching)
-IgE binds to Fc receptors on mast cells and stimulates mast cell response
-IgE will persist when bound to mast-cell Fc receptors
--no need for antigen-specific T-cell

Front 26

Sensitization overview

Back 26

1. Recognition by T-cells of the antigen
2. Proliferation of the specific T-cells
3. Differentiation of the cells to become TH2 cells
4. Production of IgE
5. Binding of IgE to Fc receptors on mast cells and basophils
--mast cells can remain sensitized for weeks or longer

Front 27

Activation Overview

Back 27

-Mast cells express high-affinity IgE Fc receptor
-IgE binds to antigen and to mast cell
--Acts as cross-link
-Mast cells are triggered to release granules upon binding with IgE Fc receptor
-Mast cells wait in tissue with IgE on surface first
--contact with allergen allows release of hsitamine
--Can be weeks, months, or years later
-Contact causes massive exocytosis of granules

Front 28

Mast cell location and activation

Back 28

-Location can lead to very different consequences and reactions
-Cutaneous anaphylaxis: annoying
-Systemic anaphylaxis: life threatening

Front 29

Inflammatory mediators released from mast cells

Back 29

-Cytokines
-Granule contents:
--hitamine
--proteases
--chemotactic factors
-Membrane phospholipids

Front 30

Primary mediators of type I hypersensitivity

Back 30

-HISTAMINE
-Proteases
-Cehmotactic factors

Front 31

Secondary mediators of type I hypersensitivity

Back 31

-Phospholipids
--make arachadonic Acid and PAF
--Arachadonic acid makes leukotrienes and prostaglandins
-Leukotrienes: important role in asthma
-Cytokines

Front 32

Mast Cell Degranulation

Back 32

-Mast cell is PACKED with granules
-Pre-formed mediators
--Can be reformed or newly synthesized
-Histamine, cytokines, chemotactic factors, heparin

Front 33

Histamine

Back 33

-Primary mediator of anaphylaxis
-Decarboxylation of histadine
-Store as histamine/heparin complex
-Binds to H1/H2 receptors
-Causes constriction of smooth muscles
-Separation of endothelial junctions, leads to vascular permeability
--Get fluid in tissues
-Can cause a small nodule at site of reaction (insect sting)
-Can cause increase in mucus secretion

Front 34

Immediate signs of systemic anaphylaxis

Back 34

-Difficulty breathing
-Asphyxiation due to constriction of smooth muscles around the bronchi of the lung
-Drop in blood pressure
--due to blood leaking into tissue spaces (permeability of blood vessels increases)

Front 35

Newly Synthesized Granules in Mast cells

Back 35

Arachadonic Acid derivatives

-Leukotrienes
--slow-reacting substance of anaphylaxis
--Prologned constriction of smooth muscle
-Thromboxanes and prostaglandins
--vasoactive, lead to bronchoconstriction
--chemotactic
-Platelet-activating factor
--Induces platelet aggregation and release of platelet contents
--contents include histamine and arachadonic acid metabolites

Front 36

Late-phase reaction

Back 36

-Cytokines/Chemokines produced during a Type I hypersensitivity response lead to accumulation of:
--eosinophils
--neutrophils
--basophils
--lymphocytes
--macrophages
-Occurs hours after allergen exposure
-Vascular congestion
-Edema
-Reaction can spread into area surrounding initial reaction

Front 37

Eosinophils

Back 37

-Involved in type I response
-Express low-affinity receptor for IgE
-Express receptors for IgG and Fc also
-IgE and IgG bound antigen can bind to eosinophils and lead to activation
-Activation results in production of inflammatory granules:
--leukotrienes, platelet-acctivating factor, major basic protein, eosinophil cationic protein

Front 38

Allergic Sensitization

Back 38

-Why to some exposures lead to reactions and others do not? Why does it vary from individual to individual?
-What makes an antigen an allergen?

In order to produce an allergic response, Th2 cells must produce IL-4
--initiates IgE production by B Cells

Front 39

Il-4

Back 39

-Produced by Th2 cells
--NEED Th2 cells to produce IL-4
-Initiates class-type switching
-Causes B-cells to produce IgE instead of IgM

Front 40

Features of Allergens

Back 40

-Proteins or glycoproteins
-Enzymatically active often
-May have biological activity that is non-enzymatic
-Can work in low concentration
-Exposure is via mucosa
-Low molecular weight
-High solubility

Front 41

Parasitic antigens that act as allergens

Back 41

-Mites

Front 42

Proteinase Allergens

Back 42

-Common and sidespread
--in Fungi, insects, plants, parasites
-Not all allergens are proteases

Front 43

Birch Pollen

Back 43

-Pollen has allergen that resembles PGE2
-Can inhibit IL-12 production by dendritic cells
-Promotes Th2 cell differentiation
--Th2 cells will produce IL-4
--will result in increased B-cell activation

Front 44

Peanut allergens

Back 44

-Can cross-link IgE on mast cells
-Some can bond to dendritic cell SIGN
-Stimulates Th2 development

Front 45

Why have hypersensitivity reactions?

Back 45

-Th2 type responses are correlated with protective immune response to GI helminths

Front 46

Hygiene Hypothesis

Back 46

Declining family size, improved household amenities, and higher standards of personal cleanliness have reduced the opportunities for cross-infection in young families.
-May result in more widespread clinical expression of atopic disease

Front 47

Type IV hypersensitivity

Back 47

-Delayed-type hypersensitivity
-Occurs on a longer time-scale, days
-Characterized by erythema (redness), induration (raised thickening)
-Infiltration of monocytes and macrophages
--few lymphocytes
-Neutrophils are not a common feature

Front 48

Induration

Back 48

-Raised thickening
-Can be distinguished from edema by applying pressure to reaction
-Induration is hard due to fibrin deposition in the lesion
-Occurs in 24-72 hours after inoculation of skin-test allergen

Front 49

Type Iv Sensitization

Back 49

1. Antigen is processed by local APCs
2. T-cells arecognize peptide-MHC on APCs
--T-cells differentiate into Th1 cells
3. Th1 cells activate T-cells, T-cell population expands
-IFN-g is produced, activates macrophages
4. Macrophages activated
--cause massive recruitment of macrophages and inflammatory cells

Front 50

Contact hypersensitivity

Back 50

-Form of delayed-type hypersensitivity (Type IV sensitivity))
-target organ is the skin
-Ex: poison ivy
--oil secreted by plant gets into the skin
--oil couples with proteins in the skin and forms new antigen
--is recognized as foreign by the body
-macrophages are released to combat foreign protein, release lytic enzymes and cause tissue damage
-Mediated by Th1 cells
-Subsequent exposure will activate Th1 cells and induce cytokine production
--48-72 hours after 2nd exposure, macrophages accumulate and redness and pustules form
-Oils are incredibly persistent

Front 51

Sources of contact allergens

Back 51

-Animals:
--insecticides, wood preservatives, floor waxes, carpet dyes, leather products, paints, house plants

-Humans:
--nickel, cosmetics, latex, drugs

Front 52

Delayed-type Hypersensitivity (DTH) test

Back 52

-tests for type IV hypersensitivities
-TB test
-Johne's disease in cattle
-Not all that useful in other species
--pig and cat is unreliable
--dog can work, but not common
--horses are very sensitive and may not be reliable

Front 53

Type II and III hypersensitivities

Back 53

-Immunological responses to IgG antibodies
-Occasionally IgG reacts with non-infectious agents to produce acute or chronic hypersensitivity reactions
-Type II: reacts to antigens on cell surfaces
-Type III: racts to soluble antigens in circulation

Front 54

Type II hypersensitivity

Back 54

-Antibodies to cell-surface antigens
-Normally benign antigens bind to surfaces of circulating blood cells
--Leads to destruction of RBCs or platelts
-Can be an uncommon side-effect to taking certain drugs
--penicillin, quinidine, methyldopa
-Includes antibody responses to cell receptors and ECM molecules
-Responses are rare, but can be very destructive

Front 55

Drug-induced type II hypersensitivity reaction

Back 55

-Penicillin, Quinidine, methyldopa
-Drug binds to cell surface
--acts as a target for anti-drug IgG antibodies
--Initiates cell destruction
-Mechanism is not clear

Front 56

Antibody-Dependent Responses

Back 56

-Type II responses
-ADCC utilizes Fc receptor on NK cells, macrophages, neutrophils, and eosinophils
-Target self-cell is opsonized by antibody
--granulocyte cannot distinguish self cell, will destroy cell
-Target cell lyses due to contact with cells with Fc receptors

Front 57

Myasthenia Gravis and antibody-mediated cell dysfunction

Back 57

-Loss of muscle tone and weakness
-Body has developed an immune response to ACh receptor
-Antibody binds to receptor, will not allow ACh to bind and create AP
-Aggressive loss of muscular function

Front 58

Complement-mediated reactions

Back 58

-Blood cells are most commonly affected
-Antibodies recruit and activate complement system
-Causes lysis of cells or phagocytosis

Front 59

Hemolytic disease in Human Newborns

Back 59

-Type II hypersensitivity
-based on Rh factor
--antigen is expressed on a large- number of human RBCs
-Mother is Rh- and fetus is Rh+
-Fetal blood leaked into the mother a few weeks before birth, response has been generated
--Mother can mount an anti-Rh response
-Fetus acquires Rh antibodies in colostrum
-Can be detrimental for 2nd birth

-

Front 60

Hemolytic disease in newborn Horses

Back 60

-HDN is relatively common in foals and mules
-Foal inherits Rh antigen from sire (not mother)
-Mare becomes sensitize to antigen during pregnancy
--due to hemorrhage in late gestation
-Fol ingests colostrum with high titers of antibodies to its own RBCs
-Foal is born healthy, will get sick several hours after suckling

Front 61

Transfusion Reactions

Back 61

-Similar to hemolytic disease
-Will develop antigens in your own blood against blood that is of a different type
--reaction will not occur with first exposure, will occur with 2nd
-Unmatched transfusions are usually fine in dogs and cats
--if an A- dog is sensitized, then gets A+ blood in 2nd transfusion, can have a severe reaction

Front 62

Drug-induced reactions

Back 62

-Drugs can act as haptens
-When they bind to cell, will induce antibody formation
-If target is platelets, will lead to thrombocytopenia

Front 63

Type II hypersensitivity diagnosis

Back 63

-Lesions contain IgG or IgM antibody
-Complement system will have infiltration of neutrophils, monocytes and mast cells
-Detect circulating antibodies against tissues involved

Front 64

Type III hypersensitivity

Back 64

-Immune complex disease
-Induced by large quantities of poorly-catabolized immune complexes
-Can be a local response (arthus reaction)
-Systemic response (serum sickness)
-Main components: immune complexes, complement, neutrophils, mast cells

Front 65

Local Type III hypersensitivity response

Back 65

-Arthus reaction
-Involves in situ formation of antigen/antibody complexes after repeated injection of antigen into sensitized patients
-Manifests as local vasculitis
-Complement is activated, recruits macrophages and mast cells
--get local inflammation
-Redness and swelling due to reaction with antigen/antibody complexes
-Occurs over several hours

Front 66

Systemic Immune complex disease

Back 66

-Immune complexes form in circulation, deposit into random tissues
-Inflammatory reactions occur at the sites of immune complex deposition
-Not directed against antigen in the tissue, directed against complexes
-In sites where there is a lot of filtration
--kidneys
--joints and connective tissue
--Skin
--heart, small vessels

Front 67

Pathogenesis of systemic immune complex disease

Back 67

-Similar to local/systemic responses
-Immune complexes activate complement
--increased vascular permeability
--Chemotaxis, neutrophils are attracted to area
--stimulation of neutrophils, neutrophils lysosomal enzymes are released

Leads to tissue destruction

Front 68

C5a

Back 68

-Binds to g-protein coupled receptors on macrophages and other cells
-Will activate
-Involved in immune complex reactions

Front 69

Neutrophil Lysosomal Enzymes

Back 69

-Cause breakdown of tissue
-Can cause platelet agregation

Front 70

Common locations for type III hypersensitivity reactions

Back 70

-Vessel wall: hemorrhage and necrosis
-Glomerular basement membrane: loss of integrity
--release of protein and RBCs into urine
-Joints: destruction of synovial membranes and cartilage

Front 71

Serum Sickness

Back 71

-Type II hypersensitivity reaction
-Results from administration from large amounts of foreign serum
-Antigen is all foreign serum proteins
--concentration is high enough to promote massive immune complex formation
-Signs: fever, vasculitis, skin eruptions, joint pain, lymphadenopathy
-Immune complexes form and deposit all over the place

Front 72

Glomerulonephritis

Back 72

-Type III hypersensitivity reaction
-Immune complex deposition in the kidney
--Activates complement, leads to increased permeability in glomeruli
-Results in loss of plasma proteins into the urine
-Architecture of the kidney glomerulus is destroyed by PMN
--will lead to renal failure over time

Front 73

Infectious Diseases

Back 73

-Can lead to type III hypersensitivity reaction
-Produces immune complexes
-Prolonged presence of antigen to presence of antibody increases change of immune complex formation

Front 74

Infectious diseases with type III component

Back 74

-Staph. Aureus -dermatitis
-Canine adenovirus- glomerulonephritis
-Feline Leukemia- glomerulonephritis
-Feline infectious peritonitis
-Bovine viral Diarrhea
-Equine infectious anemia

Front 75

Barrier Surfaces

Back 75

-Large surface areas
-Microbially dense
-Immunologically active
-Sites of chronic inflammation
--psoriasis, asthma, food allergy and IBD
--

Front 76

Commensal Bacteria

Back 76

-Can amplify or down-regulate inflammatory responses
-Can become very pathogenic once inside barrier surfaces
-Body has developed unique immune responses at barrier surfaces to keep bacteria out
-EXTREMELY prevalent, much more bacteria cells than self cells
--also have much more DNA
-Supply essential nutrients, aid in digestion, promote normal tissue homeostasis
-Developmental cues can come from bacterai

Front 77

Barrier Surface types

Back 77

-Skin
-Lung
-Nasal passages
-Gut

LOTS of surface areas to monitor

Front 78

Stem cell populations and commensal bacteria

Back 78

-Stem cells have receptors that can recognize different bacteria
-bacteria are important for developmental stage initiation
-Stem cell lineages can differentiate based on bacterial imputs
-Instruct certain areas of the body to develop properly

Front 79

Probiotics

Back 79

-Recognized as a therapeutically beneficial area
-HUGE area of research interest
-Endless therapeutic potential
-Really don't know how they work!

Front 80

health promoting commensal activities

Back 80

-Angiongenesis
-Digestion
-Enteric nerve function
-Epithelial cell homeostasis
-Fat metabolism
-Immune cell homeostasis
-Resistance to infection

Front 81

Disease causing commensal activities

Back 81

-Allergies
-Asthma
-Cancer progression and onset
-Diabetes and obesity
-Irritable bowel disease

Front 82

Characterizing commenal bacteria communities

Back 82

-Composition of bacteria changes as you move through the intestine
-Highly compartmentalized
-Bacteria populations change in different areas of the colon
--have different functions?
-Outgrowth of a community in an area where it should not be may cause a disease
--relative contributions

Front 83

Commensal bacteria populations and obesity

Back 83

-commensal gut bacteria have increased capacity for energy harvest
-leptin knockout mice have out-growths of certain bacteria that helps them break down food
-promotes environment where one bacteria is exposed to a certain food source, bacteria is able to grow and become prevalent
-Commensals are sufficient to induce obesity
--bacteria can cause obesity
-Small shifts in commensals can drive obesity pathway

Front 84

Alterations in commensal communities driving diseases

Back 84

-Obesity
-IBD
-Psoriasis
-Atopic Disorders and allergic diseases

Front 85

Antibiotic use and commensal bacteria populations

Back 85

-More treatments of antibiotics in 1st year of life increases development of asthma
-Alterations can change commensal communities to skew in a manner to promote allergic disease states
-Correlation between commensals and inflamation

Front 86

Commensal bacteria regulating detrimental effects of other pathogens

Back 86

-Dissemination of commensals is associated with disease states
-Barrier is broken by virus, commensals are able to get into body
--furthers inflammation
-Associated with progression and worse outcome of disease states

Front 87

Microbial translocation in HIV infection

Systemic Immune Activation

Back 87

-Release of commensals to the body changes with progression of AIDS
-With HIV, lose CD4 T-cell population
--become immunocompromised
--Especially in intestinal barrier
-Translocation of commensal bacteria can happen in gut
-Body has to fight off HIV and bacterial infections
-As chronic infection progresses, more LPS is secreted into blood stream
--indicates increased bacterial infections
-High indicator of how quickly HIV will progress to AIDS
-Association, not a direct relationship

Front 88

Systemic Immune Activation

Back 88

-Once bacteria break barriers, initiate pro-inflammatory cascades
-Makes individual less able to fight other infections
--Number of resources is decreased

Front 89

How to tease apart relationship between commensals and immune system

Back 89

-Use antibiotics to alter distribution of commensal communities
--Can promote growth of specific kinds of bacteria and kill others
-Temporal and spatial changes in distribution
-Selective growth of bacteria that are capable of surviving in presence of antibiotics
-Has tremendous effects on distribution of commensals in the gut

Front 90

Germ-free mice

Back 90

-Mice are born and exist in bubbles
--eat sterile food and water, taken from mother before actually "born"
-In absence of commensals, cecum becomes HUGE
--bacteria are critical for being able to break down food
--more food passes through that is not absorbed

Front 91

Immune alterations in germ-free mice

Back 91

-Altered dendritic cells and macrophages
-defective ILC and NK22 responses
-Reduced numbers of IEL
-Reduced cellularity in peyer's patches and mLN
-Fewer germinal centers in spleen
-Defective secretion of IgA
-Altered paneth cells and epithelial gene expression
-Drastic effects on T-cell population

Front 92

Commensals promoting pro-inflammatory or regulatory immune responses

Back 92

-Without IL-10, will get spontaneous colitis
--T-cells attack own epithelial cells to ward off bacteria that is constantly leaking through
--In germ-free mice, no bacteria, no inflammation

Front 93

IL-10

Back 93

Critical anti-inflammatory factor
-Produced by the body to prevent inflammation
-In airway and gut, inflammation can be very bad

Front 94

Immunologic mechanisms that promote barrier function

Back 94

-Outer mucus layer
-Inner mucus layer
-Tight junctions between cells
-Antimicrobial proteins
-Intraepithelial lymphocytes
-Transcytosis of antibodies, cross epithelial barrier
-B-cells producing IgA
-Phagocytic macrophages
-Paneth cells produce antibacterial proteins

Front 95

Mucosal Immune System

Back 95

-Barrier surfaces have a protective layer of mucus
-Inner mucus layer is usually sufficient to protect from bacteria
--Most bacteria live in outer mucus layer
-Epithelial layer has crypts and villi
--paneth cells are in crypts
--increases SA for absorption of food
-60% of the cells in the gut are immune cells
--HIGHLY immunologically active area
--exposure to food allergens and antigens in commensal bacteria

Front 96

Innate lymphoid Cell

Back 96

-Produces cytokines that maintain barrier surface
-Lives at mucosal barrier
-Small cell population
-Looks like a T-cell but does not operate in an antigen-specific way
-Depletion of cell population is sufficient to allow bacteria to get through barrier surface
-Important in development of the barrier surface, instructs development

Front 97

Adaptations of the mucosal immune system

Back 97

-M-Cells: sample external environment, monitor
-Intestinal Dendritic cells: sample external environment, monitor
-Effector mechanisms

Front 98

Lymphoid Tissue types

Back 98

-Any area that has an external opening to outside world
--accessible to bacteria and viruses

1. NALT: nasal-associated lymphoid tissue
2. BALT:Bronchial-associated lymphoid tissue
3. UTALT: Urogenital Tract-associated lymphoid tissue
4. GALT: gut-associated lymphoid tissue

Front 99

Microvilli

Back 99

-Small villi on individual intestinal cells
-Mucus layer lines the top of microvilli
-Helps aid with digestion, increases SA and aids passage of nutrients
-Mucus and microvilli are really the first defense

Front 100

Ways pathogens get into the gut

Back 100

1. Leakage: tight junctions fail, disease promote breakdown of tight junctions
--open pathway for pathogens to get through barrier
2. Epithelial Transport: M-cell acts as open passage
--antigens get through
3. Direct communication with gut: dendritic cells reach through epithelial layers and sample gut environment

Front 101

M-cell

Back 101

-Specialized epithelial cell
-Lacks microvilli
-Has opening/invagination without any mucus
--open area for passage of pathogens, "pocket" entryway into the cell
-Allows immune system to sample external environment and know what is going on
-Complex network of cells under M-cells are ready to respond to pathogens
-Apical surface has many endolytic domains for uptake and transcytosis

Front 102

Adaptations of the GALT

Back 102

-Special induction sites associated with lymphoid tissues
-Tonsils and Adenoids
-Peyer's patches
-Appendix
-Lymphoid follicles

Front 103

Induction sites in the Gut

Back 103

-Peyer's patches with M-cells right next ready to get whatever is coming through
-M-cells provide functional openings in barrier
--vesicular transport
-Peyer's patch acts as lymph node right below M cells

Front 104

Effector Sites in the gut

Back 104

-Where you actually fight the infection
-Lamina propria
-interepithelial lymphocytes
-Can help during barrier breakdown

Front 105

Follicle Associated Epithelium

Back 105

-Separates peyer's patches from the gut lumen
-has M-cells
-Epithelial dome is right below FAE
--rich in dendritic cells

Front 106

Peyer's patches

Back 106

-Secondary lymphoid tissue
-Associated with gut epithelium
-Specialized epithelial cells above that allow antigen sampling
--Allows transport of antigens through to be able to sample
-Highly enriched for B-cells
-T-cells interact with B-cells and initiate class-switching from IgM to IgA

Front 107

M-cells and pathogen uptake

Back 107

-Specialized for pathogen uptake
-Selectively adherent to multiple enteric pathogens
-Apical surface has endocytic domains to uptake and transcytose
-Active sampling process
-Distinct surface oligosaccharides promote pathogen uptake
--conserved sequences on pathogens are recognized and taken in

Front 108

Pathogens M-cells bind to

Back 108

-Cholera
-E. Coli
-Salmonella
-Yersinia enterocolitica
-Retroviruses, HIV

Front 109

Dendritic Cells in GALT

Back 109

-GALT has specialized dendritic cell populations
-Unique DC subsets in the peyer's patches and lymphoid follicles
--CD11c CD8a-CD11b, DC
-Programmed for IL-10 production
--do not want inflammation in the gut
-DC in the gut can drive tolerance, do not react to food allergens that are not dangerous
-Can directly sample bacteria across epithelial monolayers
-Conventional DCs are also present
--allow recognition and responses to pathogens

Front 110

Dendritic cell sampling

Back 110

-Cells reach across the epithelial cell layer to come into contact with antigens
-Cell will reach through barrier, come into contact with antigen, and recognize it
-In lamina propria

Front 111

Methods for sampling the gut lumen

Back 111

1. M-cell dependent sampling
-antigen is endocytosed by M-cells and passed through the epithelial cell
-Basal aspect of M-cell displays antigen to dendritic cell
2. Dendritic cell dependent sampling
-dendritic cells reach through the gaps between epithelial cells

Front 112

Specialized T-cells in GALT

Back 112

1. Conventional: CD4 or CD8 T-cells that express antibody T-cell receptor
2. Unconventional: CD4 T-cells that express TCR
--CD8aa T-cells that express antibody T-cell receptors
--Recognize antigen expressed by unusual MHC molecules

-Some cells do not undergo thymic selection, have restricted TCR repertoires

Front 113

Specialized features of the GALT

Back 113

-Peyer's patches and lymphoid follicles
-M-Cells
-Unique interdigitating dendritic cell populations, can put "feelers" through the epithelial cell layer
-Specialized T-cell populations

Front 114

Helminth Parasites

Back 114

-Ubiquitous pathogens of the GI tract
-IN humans and livestock
-infect 1/3 of the world population, mostly developing areas
-tremendous public health concern
-Highly evolved at getting through the epithelial surface
--very developed mechanisms to attach to gut
-Difficult for a B-cell or T-cell to attack something so large
-Always moving, hard to latch onto

Front 115

Helminth Parasite Feeding

Back 115

-have very developed mouth-parts
-Vampire teeth, suckers, guillotine, etc.

Front 116

Protective immunity initiation in Helminths

Back 116

-Th1 pathways: bacterial and viral pathways
-Th2 pathways: helminth infections
-Resistant mouse Th2 cells will secrete cytokines (IL-4, IL-13, IL-25)
--Produces TONS of mucus
--Promotes epithelial cells to expand, parasite cannot hold on and will be swept away
-Susceptible mice cannot produce Th2 immune response, will only mount a Th1 response
--results in uncontrolled parasitic burden
--Secretes IL-12, IFN-gamma

Front 117

Treatment of parasitic infections

Back 117

-In a regular mouse, regularly resistant, blocking Th2 response will make mouse susceptibility
-IN susceptible mouse, blocking Th1 response can be treated by blocking IL-12 and IFN-gamma cytokines
--mice can become resistant
-Finding a vaccination is hot topic of research

Front 118

Th2 cytokines mediate work expulsion

Back 118

-Polarization of Th2 cells produce effector cytokines
-Induction of antibodies brings in IgE
--Binds to mast cells and basophils
-Degranulation of mast cells and basophils can affect and destroy the parasites
-Can be used as a model for other allergic reactions

Front 119

Immunodeficiency Disease

Back 119

-Diverse group of diseases that result in increased susceptibility to infections
-Result of one or more abnormalities of the immune system
-Can be primary (genetic) or secondary (acquired)
--If acquired, individual is born with a normal immune system and change occurs during lifetime

Front 120

Primary Immunodeficiencies

Back 120

-Genetic diseases
-Defects in the immune system predispose animal to increased susceptibility to infection
-first diagnosed in the 1960's
-Currently about 110 known primary immunodeficiencies

Front 121

Cyclic Hematopoiesis

Back 121

-"Gray collie Syndrome"
-In dogs and humans, maybe more species
-Autosomal recessive inheritance
-Exhibits as hypopigmentation, coat appears silvery gray
-Cyclic fluctuation of neutrophils and monocytes/platelets
--10-14 day intervals for cycle
--regular flux of neutrophils and inverse flux of monocytes
--Neutrophils have a short half-life, monocytes have a longer half-life

Neutrophils cannot kill bacteria, cannot respond to infections

Front 122

Clinical Signs of cyclic hematopoiesis

Back 122

-Hypopigmentation
-Severe, recurrent bacterial infections
--affect respiratory and GI tracts
-Epistaxis (bleeding from nose)
-Profuse hemorrhage due to lack of platelets (thrombocytopenia)
-metabolic abnormalities, defective killing of bacteria by neutrophils

Neutrophils cannot kill bacteria, cannot respond to infections

Front 123

Neutrophil Elastase

Back 123

-Serine proteinase
-Secreted by neutrophils and macrophages during inflammatory response
-Stabilizes the membrane of neutrophils
-Traffics proteolytic enzymes of the neutrophil from internal cell to cell membrane
-Destroys bacteria and host tissue
-With Cyclic hematopoiesis, will have decreased neutrophil elastase activity
--no enzymatic activity

Front 124

Leukocyte Adhesion

Back 124

-Integrin-mediated adhesion
--All integrins are dimers
-LFA-1, CR3, CR4

Front 125

Common Integrins in Leukocyte adhesion

Back 125

1. LFA-1
2. CR3: Complement Receptor 3
3. CR4: complement receptor 4

All are dimers with CD18 and an isoform of CD11

Front 126

LFA-1

Back 126

-Integrin dimer
-CD11a and CD18
-T-cell/Antigen presenting cell interaction
-Extravasation: cell leaves circulation and goes into the tissue

Front 127

Complement Receptor 3

Back 127

-Integrin
-Dimer of CD11b and CD18
-Leukocyte adhesion and phagocystosis

Front 128

Complement receptor 4

Back 128

-Integrin
-Dimer of CD11c and CD18
-Leukocyte adhesion and phagocytosis

Front 129

Neutrophil Phagocytosis of Bacteria

Back 129

-Primary function of a neutrophil
-Phagocytosis via recognition patching or opsonization
-Can generally engulf and kill bacteria
--physical interaction with the bacteria
--random, inefficient process
-Can phagocytose opsonized bacterial via specific receptors
--Antibody is already bound to the bacteria

Front 130

Receptors in Phagocytosis

Back 130

-FcR
-C3bR
-Bacteria binds to antibodies
-Antibodies join bacteria by C3b
-Allows a much more efficient process of phagocytosis

Front 131

Extravasation

Back 131

-Neutrophils in circulation get out into tissue at site of infection
-Specific process, due to integrins
-LFA1 binds to ICAM1 ligand on endothelial cells
--Binding causes transport of cell across endothelium into tissue

Front 132

Species experiencing leukocyte adhesion deficiency

Back 132

-Humans
-Dog
-Cow
-Maybe the cat

Front 133

Leukocyte Adhesion Deficiency

Back 133

-Autosomal recessive disease
-Absence of normal leukocyte adhesion molecules on the surface of neutrophils
-Signs:
--Persistent, severe leukocytosis
--extremely high WBC count
-Cells do not have integrins but are present
--cannot respond to the infection
-No WBC at the infection, body thinks it needs more WBCs and keeps producing them in high numbers
-Recurrent pyogenic infections and wound healing
-Minimal puss formation due to no neutrophil activity
-Have to be homozygous recessive to get the disease
-Dx: lack of CD18 receptors on the surface of the cells

Front 134

Canine Leukocyte Adhesion Deficiency

Back 134

-CD18 integrin is modified
-Will not dimerize with any CD11 isoforms
-No dimer, no integrin on the cell surface
-Will have normal B-cells and T-cells, but EXTREMELY high WBCs

Front 135

Signs of CLAD

Back 135

-Retarded growth
-Umbilical abscess, umbilicus does not heal very well
--poor wound healing
-Joint involvement:
--Metaphyseal swelling in joints
--Osteomyelitis, infection in the joint
-Look for presence of CD18 on surface of cells

Front 136

Primary Immune Deficiencies in Patients

Back 136

-Mostly seen in pediatric patients

Front 137

Selective IgA Deficiency

Back 137

-In dogs and humans
-Most common immunodeficiency in humans (1:600)
-Has to do with secretory IgA in mucosal immunity
-Caused by reduced or absent IgA, esp, secretory
-Upper respiratory and GI infections are common
-Older IgA deficient dogs may be predisposed to allergies and autoimmune diseases
-Mode of inheritance is unknown
-Dx: measurement of IgA
-No secretory IgA in mucosal barriers, pathogens can get into body
-Tx: give gamma-globulin and aggressively treat infections

Front 138

Secretory IgA Function

Back 138

-Blocking action
-Prevents infectious disease agent from binding to the mucosal surface

Front 139

Treatment of Antibody Deficiencies

Back 139

-Give gamma-globulin regularly
--made from plasma pools of blood donors
--Monthly injections
-Treat bacterial infections aggressively
-Gene therapy is new and emerging

Front 140

Severe Combined Immunodeficiency

Back 140

-Most severe immunologic diseases and hardest to treat
-Many genetic causes (autosomal recessive, X-linked)
-Phenotype is pretty uniform
-B-cell problem and a T-cell problem
-Patient cannot mount a normal B-cell and T-cell mediated immune response
-If suspected, do not immunize with a modified live-virus vaccine!

Front 141

SCID and recombination

Back 141

-SCID is due to defects in recombination
-T-cell needs a normal alpha-beta chain
-B-cell needs a normal heavy chain and light chain
-No normal receptors, no normal function

Front 142

B-T-SCID

Back 142

-Occurs in human, horse, and dog
-No B-cells or T-cells

Front 143

Equine SCID

Back 143

-Severe Combined Immunodeficiency
-Foals are clinically normal for 2 months of life
--Still on maternal antibodies from colostrum
-Primary pathogen is an adenovirus
--causes respiratory problems
--Becomes systemic
-Also see bronchopneumonia, chronic diarrhea (cryptosporidium parvum)
-Opportunistic infections, cause disease in immunocompromised hosts
--healthy hosts are fine
-Fatal by 5 months of age
-If suspected, do not immunize with a modified live-virus vaccine!

Front 144

Equine SCID pathology

Back 144

-Very low lymphocytes, below 1000/ml
-Total WBC can be low, normal, or high
--depends on how neutrophils respond to reaction, this is not a neutrophil disease
-Thymus will be small and fatty
--Hypoplastic thymus, decreased development

Front 145

SCID immunologic features

Back 145

-Low to absent B-cells or T-cells, or both
-no serum IgM
--not produced in colostrum, will not be present in foals at all
-Low IgG and IgA, especially post-colostrum
-Cannot produce antibody after specific immunization
-No T-cell proliferative response to mutagenic stimulation
--should proliferate, but don't
-If suspected, do not immunize with a modified live-virus vaccine!

Front 146

Genetics of equine SCID

Back 146

-2-3% of arabian foals
-1:1 male/female ratio
-26% of arabian mares and stallions carry the trait
-DNA-dependent protein kinase defect

Front 147

DNA Protein Kinase

Back 147

-Required for V(D)J recombination
-Needed to repair double-strand breaks in DNA
-Present in all cells

Front 148

RAG vs. DNA Protein Kinase

Back 148

RAG: breaks open the DNA to allow recombination
-defect produces a defect in recombination

DNA-PK: puts DNA back together once it has been broken open
-happens after recombination happens

RAG and DNA-PK work sequentially in DNA recombination

Front 149

SCID in Jack Russel Terriers

Back 149

-Can't repair DNA, cannot repair cells
-Can cure the immunodeficiency but individual will probably die of cancer

Front 150

Cytokine Signaling Pathways

Back 150

-Cell surface has a cytokine receptor that is at least a dimer, sometimes a trimer
-Binds cytokine ligands to activate tyrosine kinases
--JAK/STAT
-STAT receptors are activated to dimerize via phosphylation
--enter nucleus and influence different DNA sequences

Front 151

X-Linked Severe Combined Immunodeficiency

Back 151

-Most common form of SCID in children and dogs
--60% of cases are X-linked
-"Bubble boy" disease
-

Front 152

Canine X-linked SCID characteristics

Back 152

-Failure to thrive, growth retardation
-Fatal between 8 and 16 weeks of age
-Low to absent peripheral T-cells
--B+/T- SCID, have B-cells that do not function normally
-Serum IgM may be normal
-Low to absent IgG and IgA
-Lack of a specific IgG antibody response, no IgG
-T-cells cannot proliferate
-No mucosal-associated lymphoid tissue

Front 153

Do Not immunize an immunodeficient animal with a modified live vaccine

Back 153

you will kill it

Can always use a killed vaccine or other type of vaccine!

Front 154

X-linked SCID thymus

Back 154

-Will be small, hypoplastic
--should be HUGE in a young animal
-T-cells are not being made
-Will not have a well-defined cortex and medulla
-Thymus will be mostly epithelial cells, hardly any thymocytes

Front 155

Suspect immunodeficiency if...

Back 155

1. dog has recurring infections
2. dog is particularly susceptible to infections
3. no palpable lymph nodes
4. infections from unusual agents
5. Non-responsive to normal therapy

Front 156

B-cell development in X-linked SCID

Back 156

-Pro-B cell→ Pre-B cell → Immature B-cell → Mature B-cell
--Should then produce a mature B-cell with IgG and IgA
--Does not produce mature antibodies
-Class switch defect
-Occurs late in b-cell development

Front 157

T-cell development in X-linked SCID

Back 157

-Defect is in the transition from a double negative thymocyte to a double positive thymocyte
-Cannot become mature T-cells, cannot progress from CD4-/CD8- stage
-Genetic defect has to do with IL2 receptor on X chromosome
--Gamma chain of the receptor is on the X-chromosome

Front 158

Gamma chain of IL2 receptor

Back 158

-Is on the X chromosome
-Source of X-linked SCID
-Is a component of IL4, IL7, IL9, IL15, IL21 receptor
--component of 6 different IL receptors
-"Common gamma chain"
-Causes very serious issues!
--cytokines are responsible for development and function of the entire immune system
-Real effects are seen with IL4, the cytokine that allows for class switching

Front 159

Carrier detection for SCID

Back 159

-PCR
-Look at fragments present
-Carrier has both normal and mutated segments
-May not be able to treat the individual patient, but can put together a breeding plan to avoid future carriers or affected individuals

Front 160

Treatment of Immunodeficiency disease

Back 160

Antibody deficiencies:
--supportive therapy (antibiotics)
--Intravenous immunoglobulins

SCID and T-cell deficiencies:
--Hematopoietic stem cell transplantation
--Gene therapy

Front 161

Bone Marrow Transplantation

Back 161

-HLA Identical: donor and recipient are perfectly matched
--can harvest the bone marrow from the donor and give it right to the recipient
--do not need to worry about graft vs. host disease
-HLA-haploidentical: half-matched donors
--can be a parent
--Cannot have mature T-cells in what is being donated
--have to deplete T-cells from the bone marrow innoculum

Front 162

Graft vs. Host disease

Back 162

-Donor and recipient are not matched exactly
-Mature T-cells from donor will kill of tissue in the recipient
-Do not have too worry about this when donor and recipient are identical
--liklihood of identical donor is 20%

Front 163

HLA Identical bone marrow transplant

Back 163

-Donor and recipient are perfectly matched
-can harvest the bone marrow from the donor and give it right to the recipient
-do not need to worry about graft vs. host disease
-Have mature T-cells all set to go to combat whatever else comes along

Front 164

HLA Haploidentical bone marrow transplant

Back 164

-Half-matched donors, donor and patient have half of the same material
-can be a parent
-Cannot have mature T-cells in what is being donated
-have to deplete T-cells from the bone marrow innoculum
-Higher risk of nonengraftment
--30-50% of patients need 2nd or 3rd transplant
-Delayed T-cell reconstitution
--don't have any mature t-cells around to fight off whatever infection might come along
--Delicate balance between having no mature T-cells and having T-cells that can fight off infections
-Always have potential for graft vs. host disease

Front 165

Delayed T-cell reconstitution

Back 165

-Whole bone marrow transplants have very fast T-cell reconstitution
--patient can go home much faster
--Mature t-cells from innoculum can expand peripherally and provide some protection to the recipient
-T-cell depleted bone marrow transplant will not have mature T-cells for 5-6 months
--long time for possible infection!
--Have to grow T-cells from scratch, T-cell precursors have to undergo maturation in the thymus (basically like starting at development)

Front 166

Gene Replacement for X-linked SCID

Back 166

-Not really "gene therapy"
-Put in a normal gene
--still have the defective gene, but also have a normal gene incorporated into the host chromosome
-Normal gene can be transcribed and put a normal gamma-chain on the cell surface

Front 167

Integrated Genetics Chromosome

Back 167

-For hematopoietic Stem Cells, Integrate retroviral vectors into a host chromosome
-Want to get the normal gene into the true hematopoietic stem cell
--pleuri-potent and self-renewing stem cells
-Can produce all lines, and will be present for the life of the animal

Front 168

Retroviral Transduction

Back 168

-Only approved method of retroviral gene therapy
-Ex-vivo therapy
-Take cells from patient, put in culture and stimulate to start dividing
--add growth factors
-Expose cells to vector, then put back into the patient

Front 169

Hematopoietic Stem Cells as target cells

Back 169

-Pluripotent, self-renewing cell
--if you get a factor into it, the factor will be replicated to all cells in the line
-In normal body, cell is quiescent
--have to activate with cytokines

Front 170

Cytokine activation of HSC

Back 170

-Causes proliferation of hematopoietic stem cells
-Cells enter differentiation pathway
-Trandsuction of cells other than pluripotent stem cells are committed progenitors

Front 171

Naive T-cell proliferation in Gene Therapy

Back 171

-VERY robust T-cell regeneration within the first 10 months
-Over time, T-cells start to decline and disappear
--have to re-do gene therapy every few years
--redoing therapy has serious side-effects
-Indicates that instead of getting into a HSC, retroviral factor got into a T-cell progenitor
--over time, numbers will decline

Front 172

Side-effects associated with T-cell gene therapy
Insertional Mutagenesis

Back 172

-Serious side affects
-Patients develop T-cell leukemia due to insertional mutagenesis
-Caused by vector inserting into oncogenes instead of in other area
--same oncogene for all, MLO2
-Vectors will integrate into MLO2 instead of HSC
--MLO2 is only active during early hematopoiesis in hematopoietic stem cells, perfect time for integration

Front 173

Autoimmunity

Back 173

-Immune system recognizes self antigens as foreign
-Own cells are now "foreign"
-Immune system needs to be able to tell the difference between self and non-self to be effective
-Failure of tolerance to own cells

Front 174

Immune-mediated hemolytic anemia

Back 174

-Appears as jaundice
-Body recognizes RBC as foreign, tries to eliminate them
-Antibodies coat surface of RBCs, bind to Fc receptors, and are phagocytosed by macrophages
-Build up of bilirubin

Front 175

Immune-Mediated Thrombocytopenia

Back 175

-Platelets are recognized as foreign
-No platelets, develop spontaneous bleeding

Front 176

Tumors and the Immune system

Back 176

-Tumor cells are "self"
-Want immune system to recognize and get rid of tumors, but often it does not

Front 177

Immune system requirements

Back 177

-Recognize and destroy foreign "non-self" antigens
--bacteria, viruses, fungi, parasites
-Distinguish between self and non-self antigens
-Leave self-tissues unharmed during an immune response

Front 178

Tolerance

Back 178

-A state of unresponsiveness to a particular antigenic epitope
-Can only tolerize cells that have antigen-specific receptors
--B-cells or T-cells, mature or immature lymphocytes
-Trying to induce anergy (resting, no response to antigen) or deletion (getting rid of cells that recognize self-antigen)

Front 179

Why is tolerance necessary

Back 179

-Prevents autiommunity
--non-tolerized, self-reactive lymphocytes may attack self-tissues
--results in autoimmune diseases
-Can use tolerance to find new ways to enhance tolerance (transplants, grafts) or suppress tolerance (cancer)

Front 180

Conditions to enhance tolerance

Back 180

-Want to make body more tolerant
-Transplants
-Grafts

Front 181

Conditions to suppress tolerance

Back 181

-Cancer
-Want to induce the autoimmune state

Front 182

T-cell receptor generation

Back 182

-T-cells recognize non self-antigen presented in context of self MHC molecules
-Need co-stimulation via specific T-cell receptors
-IL2 promotes proliferation
-Need to have repertoire of T-cells that can recognize any pathogen that you might come into contact with
-Occurs during T-cell development in the Thymus

Front 183

T-cell Receptor

Back 183

-Composed of alpha and beta chains
-Resembles a membrane bound Fab fragment
-Transmembrane domains are associated with polypeptides
--polypeptides are involved in signal transduction, make up CD3 complex
-30,000 identical receptors on each t-cell
--on each t-cell, all receptors are the same

Front 184

Alpha and beta chains on T-cell Receptor

Back 184

-Determine specificity of the T-cell
--determine what it recognizes
-Need to have repertoire of T-cells that can recognize any pathogen that you might come into contact with
-Gives potential for enormous diversity

Front 185

T-cell repertoire generation

Back 185

-generated by random TCR gene recombinations
-Provides for enormous receptor diversity
-Germline DNA rearranges and recombines randomly to produce alpha chain and beta chains
-HUGE amount of random recombination gives huge numbers of recognition
-Randomness is KEY
-Also generates cells that recognize self
--unfortunate side-effect
--have to get rid of them

Front 186

Clinical applications of TCR gene recombinations

Back 186

-Rearranged DNA is a single V, D,J segment
-Can design primers to perform PCR that will amplify rearranged DNA
-If DNA is not rearranged, no product produced
-If DNA is rearranged, can do a PCR to generate a band
--Can find which patients have polyclonal T-cell populations vs. monoclonal T-cell population
-Single band= all bits of DNA are the same length
--all TCRs are exactly the same, monoclonal population
--indicates cancer
-Smear= all bits of DNA are slightly different sizes
--all TCRs are different sizes, polyclonal population

Front 187

Monoclonal PCR analysis

Back 187

-one TCR is proliferating out of control
-CANCER

Front 188

Tolerizing autoreactive lymphocytes

Back 188

-As TCR repertoire is randomly generated, T-cells that recognize self will be produced along with many others
-Mechanisms must be in place to deal with autoreactive T-cells
--prevent T-cells from damaging/destroying self tissues and causing autoimmune disease
--Have to destroy cells or make them unresponsive
-Must be rendered unresponsive to self antigen
-Deleted in thymus or inactivated and deleted in periphery

Front 189

Central tolerance

Back 189

-Autoreactive T-cells are deleted in the thymus

Front 190

Peripheral Tolerance

Back 190

-Auto-reactive T-cells are inactivated and deleted in the periphery

Front 191

Benefits to understanding tolerance induction

Back 191

1. Understanding pathogenesis of autoimmune disease
2. Successful manipulation of immune system or therapeutic purposes
--transplants
--therapies for tolerance induction
--others

Front 192

Graft rejection

Back 192

-Mature immune system recognizes between self and non-self and rejects foreign tissue

Front 193

introduction of foreign cells to a neonate

Back 193

-Young immune system is "educated" for other mouse cells
-System develops with other cells
-Grafts from other mouse system will survive in neonate when it grows up
-Indicates that self/non-self discrimination is developed during immune system maturation
-Can introduce ANYTHING at a young age and individual will accept it as its own
--will not reject tissue ever

Front 194

Positive Selection

Back 194

-Selecting for cells that recognize self MHC
--Self MHC expressed on thymic stromal epithelial cells in thymic cortex
-Occurs in thymic cortex
-Results in self-tolerant, self-MCH restricted antigen specific T-cell
-Cells can "see" self MHC receptors

Front 195

Negative selection

Back 195

-Select for cells that do not recognize self-antigen
-Get rid of cells that react to self
-Occurs in thymic medulla
-Dendritic cells or macrophages present self MHC and self antigen

Front 196

Environment in which T-cell matures determines MHC molecules to which it becomes restricted

Back 196

-Radio-resistant thymic stromal epithelial cells are responsible for positive selection
-T-cells are re-educated in the thymus
-Only cells that are same type as present initially are allowed to survive
-Other cells that do not recognize correct MHC complex die through neglect

Front 197

Bone marrow grafts and MHC molecules

Back 197

-Grafts will reconstitute immunity if there is at least one MHC molecule in common between the donor and the recipient
-If no common MHC, transplant will not work
-If donor has one same and one different, cells with different MHC complex will die due to neglect

Front 198

Negative Selection

Back 198

-Lymphocytes that recognize self antigens are eliminated
-Occurs in thymic medulla
-Every single antigen in body is presented by Dendritic cells and macrophages to T-cells
-Bone marrow derived DCs and macrophages are responsible for self-antigen presentation
-If a cell that happens to recognize self-antigens is made via random recombination, is eliminated in this step

Front 199

Positive and Negative Selection summary

Back 199

-Enormous TCR diversity is generated by random rearrangement
-Only T-cells that recognize self MHC are allowed to progress through the thymus
--positive selection
-T-cells that recognize self-antigen (autoreactive) are deleted in the thymus medulla
--negative selection
-regcognition of self vs. non-self and tolerance induction occurs during maturation of the immune system

Front 200

Problems with Central tolerance

Back 200

-Not a 100% foolproof system
-Errors account for autoimmune diseases
-Unlikely that all self antigens are represented in the thymus
-some self-reacting antigens may "slip through"
-Peripheral tolerance mechanisms exist
--ensure that self-reactive t-cells in periphery are not activated

Front 201

Peripheral Tolerance Mechanisms

Back 201

-Ensure that self-reactive T-cells that "slipped through" negative selection are not activated
-Mechanisms in the periphery are important for maintenance

Front 202

3 mechanisms of peripheral tolerance

Back 202

1. Anergy: state where t-cells are unable to respond to antigens
--reversible state
--reason for flare-ups
2. Ignorance: T-cell is prevented from "seeing" self-antigen
--antigen is behind an immunological barrier
3. Suppression: active process mediated by regulatory T-cells
--Regulatory T-cells decrease the immune response

Front 203

Two Signals required to activate T-cells

Back 203

-CD28 and CD80/CD86 AND TCR MCH interaction
-In absence of 2nd signal (no co-stimulation), anergy is induced
-T-cell can see antigen, but cannot see signal #2

Front 204

Properties of Anergic Cells

Back 204

-Generally survive but are unable to proliferate when re-exposed to antigen
-Anergic state is reversible
--do not go away, just hang out
--less absolute mechanism for enforcing tolerance
-Anergy can be reversed in presence of IL2

Front 205

IL2 and Anergy

Back 205

-T-cells that have been anergized can be reversed in the presence of IL2

Front 206

Therapeutic relevance of Co-stimulatory blockade

Back 206

-Inducing anergy in certain cells
-Block co-stimulatory signal to prevent activation of T-cells
-CTLA4-Ig like molecules bind to CD80/CD86 on APC and block co-stimulation
-T-cell cannot get co-stimulation

Front 207

Clinical settings for a co-stimulatory blockade

Back 207

1. Autoimmunity, use to prevent auto-reactive T-cells
2. Immune suppression with transplants

Does not cause blanket immunosuppression
-can still respond to other things you have been exposed to
-still have B-cell and other immune function
-Does not wipe out immune system completely
--uses and maintains immune system
-Introduces anergy to graft and any introduced pathogens
--will have anergy to whatever pathogens are introduced

Front 208

Naive T-cells and co-stimulation

Back 208

-Naive T-cells are much more dependent on co-stimulation than memory T-cells
-Will be inhibited by CTLA4-Ig drug

Front 209

Cats with Renal Transplantation

Back 209

-Also had toxoplamsa
-Immunosuppressed to be able to accept transplant
--Suppressed entire system
-Body could not fight against other latent infections
-CTLA4-Ig allows immune system to be maintained without decimating the entire immune system

Front 210

Treatment options for IMHA

Back 210

-Replace everything that has gone away
--RBCs
--Platelet transfusions
-Immunosuppressive drugs
-Splenectomy
-Thromboporphylaxis
-Co-stimulatory blockade???

Front 211

Ignorance in peripheral tolerance
Immune Privileged Sites

Back 211

-Some lymphoid cells may not have been exposed to some self-antigens
--late-developing antigens
--Antigens sequestered in immunologically privileged sites
-When barrier is broken due to trauma or surgery, body will attack cells as "foreign"
--autoimmune response
-Tumors in barrier sites go undetected
-Foreign tissues transplanted into closed-off sites are less prone to immunological attack
-Cells in immune privileged sites express FAS-Ligand
--FAS-Ligand interacts with T-cells and kills them
--T-cell is deleted so it does not cause problems within the cell

Front 212

Examples of failed peripheral tolerance associated with antigen exposure

Back 212

Situation where T-cells can now "see" antigens
1. Mumps (Paramyxovirus)
--can cause orchitis, inflammation in testes
2. Lens proteins and phacogenic uveitis
--perforating injury, retained lens material after cataract extraction
--Development of autoantibodies and granulomatious reaction associated with auto-reactive T-cells
3. Cartilage-Polychondritis-Antibodies: reactive to collagen II
--rheumatoid arthritis

Front 213

T-regulatory cells in peripheral tolerance

Back 213

-Function is to limit normal T-cell responses
-Inhibit self-reactive T-lymphocytes in an antigen-specific manner
-Actively suppress normal T-cells
-Can be transferred from a tolerant individual to a non-tolerant individual
--will produce antigen-specific tolerance in the recipient (infectious tolerance)
-Harnessing action of regulatory T-cells can provide new therapy for autoimmunity and graft acceptance

Front 214

T-reg cells

Back 214

-CD4 CD25 (IL-2R) T-regs
-Antigen-specific vs. non-specific suppression
-Secrete immunosuppressive cytokines
--IFN-gamma: inhibits IL4 B-cell class switching
--IL4: allows B-cell class switching
--IL10: inhibits development of TH1 responses
--TGFb: suppresses B and T cell proliferation
-CD8 suppressors can be cytotoxic to self-reactive T-cells

Front 215

Regulatory T-Cells and Transplantation tolerance

Back 215

-T-regs moderate tolerance to self and allogeneic antigens
--suppress effector T-cell functions
-2 types:
--Natural T-regs (produced by thymus
--Adaptive T-regs (induced by periphery
-Can modulate immune responses via direct cell-cell contact or through inflammatory process

Front 216

Natural T-regs

Back 216

-Produced in thymus
-Suppress effector T-cell functions and moderate tolerance to sell and antigens
-High surface expression of IL-2Ra
-intracellular expression of FoxP3
-Modulate immune response via direct cell-cell contact and secretion of soluble factors
-Can effect T-cell directly or through induction of tolerogenic APCs

Front 217

Tolerogenic APCs

Back 217

-Induced by natural T-reg cells
-Tolerize antigen-specific effector cells
-Promote differentiation of naive effector T-cells into adaptive regulatory T-cells
--adaptive regulatory t-cells inhibit effector T-cells with different antigen specificities
-Do not up-regulate co-stimulatory factors
--T-cells are anergized (no co-stimulation)

Front 218

Cyclophosphamaide

Back 218

-Preferentially inhibitory effect on T-reg cells
-Do not suppress immune system as a whole at the same time
-Can worsen certain diseases and help with others
--bad for IMHA
--Good pre-cancer vaccine

Front 219

B-cell Tolerance

Back 219

-Random rearrangement of BCR genes
-Occurs in bone marrow
-BCR repertoire is generated randomly
-B-cells that recognize self-antigens will be produced inadvertently
-B-cells require T-cells to function properly
--B-cell tolerance follows T-cell tolerance

Front 220

B-cell repertoire generation

Back 220

-In Bone marrow
-Generated by random BCR gene recombinations
--gives enormous receptor diversity
-VJ regions combine
-Immature autoreactive B-cells are deleted or anergized in the bone marroe

Front 221

Deletion of autoreactive B-cells

Back 221

-Occurs in bone marrow
-Multivalent self molecule recognition "cross-links" antibodies
--cell gets death signal
-Soluble self molecules induce anergy
-No recognition of self, cell can get out into periphery and mature

Front 222

Peripheral B-cell tolerance

Back 222

-Mature B-cells in periphery that recognize self-antigen are either anergized or commit apoptosis
-Anergy occurs when autoreactive B-cells sees soluble antigen
--eventually over time, will commit apoptosis
-Apoptosis occurs over time, or when autoreactive B-cell sees membrane-bound or particulate antigen

Front 223

B-cell tolerance and T-cell help

Back 223

-B-cell tolerance in the periphery relies on the fact that B-cell activation requires T-cell help
-If B-cell does not have help from T-cell due to Tcell anergized or tolerized, B-cell will not be useful
-NEEDS T-CELL TOLERANCE
-T-cell produces interleukins 4,5,6 to get B-cell to work
-T-cell tolerance prevents auto-reactive antibody formation

Front 224

Horror Autotoxicus

Back 224

-Paul Erlich
-The unwillingness of the organism to endanger itself by the formation of auto-antibodies
-"Antibodies against self cannot be formed"
-Not true, can form antibodies against self
-Formation of autoantibodies is prevented by certain mechanisms

Front 225

Autoimmunity

Back 225

-Results from activation of auto-reactive T-cells (root of entire process)
--Support production of auto-antibody by B-cells, T-helper support B-cells
--Damage tissues directly
-Associated with abnormalities in the generation and maintenance of self-tolerance in T-cells

Front 226

General model for Autoimmunity

Back 226

-Some agent initiates immune response and causes inflammation of infected tissue
-Combined with genetic background of individual and environmental influences and presence of auto-reactive T-cells makes "perfect storm"
-All factors have to come together to produce a clinical problem

Front 227

Factors contributing to "perfect storm" of autoimmune reaction

Back 227

1. Genetic background of the individual
2. Environment of affected tissue
3. Presence of self-reactive T-cells

Factors influence immune response and severity

Multifactorial effect
--hormonal influences

Front 228

Pathogenic Mechanisms leading to non-tolerant T-cells

Back 228

1. Failure of the thymic education
2. Novel self-antigen exposure due to breaking of ignorance or immune privileged sites
3. Molecular mimicry of pathogen that looks like self-antigen
--can inadvertently activate cells against self
4. Breakdown of peripheral tolerance by inflammation
5. Antigen non-specific lymphocyte activation
--super antigens activate T-cells in non-antigen specific way

Front 229

Infection and Autoimmunity

Back 229

-Immune diseases are exacerbated by infection
-Infections can induce autoimmunity via:
1. bystander T-cell activation (breakdown of peripheral tolerance)
2. Molecular Mimicry
3. Non-specific lymphocyte activation

Front 230

Bystander T-cell Activation

Back 230

1. Infection, dendritic cell picks up antigen, becomes activated, expresses antigen in context of MHC
--activates T-cell it is supposed to activate
2. T-cell is activated
--produces IL-2, INF-g
3. IL-2 can activate anergic self-reactive t-cells
--can go on to support self-reactive antibody production
--Antibodies will go on to cause tissue damage

Front 231

INF-Gamma

Back 231

-Causes aberrant expression of MHC on tissues
-Important in thyroid diseases

Front 232

Molecular Mimicry

Back 232

1. Normal t-cell comes along, reacts to specific pathogenic antigen
-TCR recognizes bacterial peptides that look similar to self-peptides
2. Other cells are activated and go off to react to self tissues
3. Auto-antibody formation occurs

Front 233

Non-specific Lymphocyte Activation

Back 233

1. Superantigens activate T-cells non-specifically
-T-cell and MHC are cross-linked
-Specificity of the t-cell does not matter
-Receptor is activated in a totally different manner

Front 234

Bystander activation

Back 234

-APC can activate normal T-cells by presenting antigen
-In a similar area, can uptake already damaged tissue
--Will present own damaged tissue as an antigen
-With appropriate co-stimulation can activate t-cells that are reactive to self

Front 235

IMHA associated to vaccination

Back 235

-Temporal association with IMHA cases and months post-vaccination
-Most cases of IMHA occurred within 1 month of vaccination
-Vaccines cause immune mediated diseases via bystander effect
--cause inflammation and immune response
--Autoreactive t-cells can become reversed and set-up immune-mediated disease

Front 236

Can make autoreactive t-cells by vaccination

Back 236

-can induce antibodies by vaccination
-Injection of saline can also stimulate auto-antibodies
--just introducing damage can result in auto-immunity

Front 237

Molecular mimicry

Back 237

-Dendritic cell takes up pathogen and presents it to t-cell
--T-cell is activated
-T-cell kills pathogen, and also cross-reacts with self-antigen
-Can be a weak reaction, but will kill cell and support generation of auto-reactive antibodies
--stimulates B-cell reaction, antibodies are made

Front 238

Molecular Mimicry Diseases

Back 238

1. Type I diabetes Mellitus, GAD 65 auto antigen, Coxsackie virus pathogen
2. Rheumatoid Arthritis, HSP 60 auto antigen, M. tuberculosis pathogen
3. K9 Rheumatoid Arthritis, DLA/collagen auto antigen, CDV pathogen
4. MS, Myelin basic protein auto antigen, multiple viruses as pathogens
5. Lyme's associated arthritis, CD11a/CD18 auto antigen, Borreli Burgdorferi pathogen

Front 239

Antigen Non-specific Lymphocyte Activation

Back 239

-Superantigen cross-links MHC receptor and T-cell beta chain receptor
--Activates T-cells
-Totally independent of the specificity of the T-cell receptor
-T-cell response can be 25% of population
--causes massive cytokine production
--"Cytokine Storm" (toxic shock syndrome)
-Can also activate self-reactive t-cell populations, will cause autoimmune reaction

Front 240

Factors influencing pathogenesis of t-cell mediated autoimmune disease

Back 240

1. Genetic Susceptibility
--specifically genetics of MHC class II
2. Concurrent infections/inflammation
3. Susceptibility of target organ to T-cell mediated damage
4. Environmental influences
5. Hormonal influences

All factors come together

Front 241

MHC types and autoimmune susceptibility

Back 241

-Certain MHC types can predispose individuals to certain diseases
--rheumatoid arthritis, MS, lupus, insulin-dependent diabetes mellitus
-MHC II presents peptide antigens, may have something to so with antigen selection and presentation
-Genetic components other than MHC increase the chances of autoimmune diseases
-Does not always develop disease, just increases risk
--clearly more factors are involved

Front 242

Infectious agents and autoimmunity in the Dog

Back 242

-Canine Distemper virus and rheumatoid arthritis
-CDV proteins and antibodies to proteins are present in synovial fluid of dogs with RA, but not OA
-Degree of molecular mimicry?
-Antibodies to IgG rheumatoid factor only bind to IgG molecules that have bound to antigen and undergone conformational change
--exposes hidden epitopes

Front 243

Rheumatoid Factor

Back 243

-Antibody that recognizes Antibody bound to Antigen

Front 244

Environmental Influences on Auto-Immunity

Back 244

-Physical damage or infectious etiologies
-Releases sequestered antigens from privileged sites
-Activates "ignorant" autoreactive T-cells
-Up-regulate co-stimulatory molecules on either APCs or non-antigen presenting cells
--activates anergic cells

Front 245

Hormonal Influences on Autoimmunity

Back 245

-not sure how it works
-Auto-immune diseases occur more often in females than in males

Front 246

Drugs for Tx of autoimmunity

Back 246

1. Corticosteroids
2. Cyclophosphamide
3. Azathioprine
4. Cyclosporine
5. Mycophenolate
6. IVIG
7. Leflunomide

Most are blanket-suppressing agents, not antigen-specific

Most suppress cellular proliferation, depress formation of cytotoxic T-cells and B-cell proliferation
--will have side-effects on other rapidly-dividing cells

Front 247

Corticosteroids as Immunosuppressive agent

Back 247

-Mainstay therapy for autoimmune diseases
-Act at almost every step in immune response
--block neutrophils and monocytes
--inhibit APCs
--Suppress T-cell proliferation and effect of cytotoxic T-cells
--affect B-cell proliferation
--Uptake of antigens

Front 248

Cyclophosphamide

Back 248

-Alkylating agent
-Cross-links DNA strands
-Leads to immediate lymphocyte cell death or death during mitosis
-Inhibits cell division

Front 249

Azathioprine

Back 249

-Anti metabolite
-Inhibits purine synthesis and impairs DNA synthesis
-Prevents proliferation of rapidly-dividing cells

Front 250

Vincristine

Back 250

-Mitotic spindle inhibitor
-Interferes with cell division

Front 251

Cyclosporin A

Back 251

-Inhibits TCR signal transduction and IL-2 production
-Profound effect on all T-cell functions

Front 252

Leflunomide

Back 252

-INhibits de novo pathway of pyrimidine biosynthesis
-Inhibits B and T cell proliferation
-Can cause GI toxicity

Front 253

IVIG

Back 253

-Unknown mode of action
-Decreases autoantibodies
-Saturated and blocks macrophage Fc receptors
-Contains anti-idiotypic antibodies
-Down-regulates adhesion molecules on T-cells and endothelial cells
-Can cause anaphylaxis, hyperviscosity, and thromboemolism

Front 254

Mycophenolate Mofetil

Back 254

-Inhibits enzymes necessary for de novo purine synthesis in B and T cells
-interferes with cell cycle
-Blocks IL-2 mediated proliferation
-Can cause GI hemmorhage, diarrhea, anorexia

Front 255

Gold Salts

Back 255

-Selectively stimulate production of anti-inflammatory cytokines
--IL4, IL10
-Decresae IFN-gamma

Front 256

Antigen-specific therapy to induce tolerance

Back 256

1. Parental antigen administration: works well in allergy, limited success as autoimmune treatment
2. Mucosal antigen administration: limited success

Front 257

Costimulatory Blockade

Back 257

-CTLA4-Ig
-Binds to CD28/B7 and inhibits co-stimulation
-Induces anergy

Front 258

Immunomodulation therapies to induce tolerance

Back 258

1. Co-stimulatory blockade
2. Administration of suppressor t-cells
3. Antagonism of inflammatory cytokines
--inflammation causes clinical signs
--block IL1 or TNF-a

Front 259

Type II Diseases classified by immunopathogenic Mechanism

Back 259

-Antibody targets antigens present on cell surface or matrix antigens
1. IMHA/AIHA
2. Myasthenia Gravis (directed at ACH receptor)
3. Skin diseases

Front 260

AIHA va IMHA

Back 260

AIHA: autoimmune hemolytic anemia
--associated with antibody responses against and antigen

IMHA: Immune mediated hemolytic anemia
--associated with something foreign on the surface of blood cells
--not really a real auto-immune disease

Front 261

Type III immune diseases with autoimmune mechanism

Back 261

-Immune complex diseases
1. Lupus
--autoantigen is DNA, histones, ribosomes

Front 262

Type IV autoimmune diseases

Back 262

-T-cell mediated diseases
1. Insulin-dependent diabetes mellitus
2. Rheumatoid arthritis
3. MS (in people only)

Front 263

Immune Mediated Hemolytic Anemia
IMHA

Back 263

-S/: lethargy, weakness, decreased appetite, diarrhea
-Pale, yellow, tachycardic, vomiting, splenomegaly
-VERY low PCV, anemia
-Hematological features:
--RBCs clump, (persistent autoagglutination) are coated with antibody that is sticking RBCs together
--spherocytosis, RBCs are no longer donut shaped, no central pallor (piece of membrane is gone, volume is smaller)
--young RBCs, polychromatophils

Front 264

IMHA mechanism of action

Back 264

-Antibodies directed against RBC membrane components or foreign antigens present on surface of RBCs
-May be idiopathic or secondary to underlying diseases
-RBCs have antibody on surface
-Macrophages take away RBCs
--create spherocytes or remove completely
-RBCs are tagged for depletion

Primary: autoimmune disorder
Secondary: antibody is formed due to underlying antigenic stimulus
--stimulus can be a drug, infectious disease, neoplasia

Front 265

Secondary immune disorder

Back 265

-Antibodies form and destroy self cells due to underlying antigenic stimulus
-Drugs: sulfas, cephalosporins
-Infectious disease: Ehrlichia, Babesia
-Neoplasia

Front 266

Mechanism for RBC destruction in IMHA

Back 266

1. Extravascular hemolysis: IgG antibodies and complement system targets RBCs for phagocytosis by reticulo-endothelial system
--Fc and C3b receptors on cells of RES
--Destruction or partial removal of membrane, leading to spherocyte formation
2. Intravascular Hemolysis: IgM attaches to RBC and activates complement
--more severe, Hb is released everywhere in vasculature, not contained in RBCs

Signs: lethargy, paleness, tachycardia, low RBC, jaundice, hemoglobinemia, hemoglobinuria

Front 267

IMHA Extravascular Hemolysis Pathogenesis

Back 267

1. Molecular mimicry or breakdown of peripheral tolerance
2. RBC is coated with antibodies
3. Complement system is activated and deposited on surface of RBCs
4. RBCs are taken out by cells of RES

Front 268

IMHA intravascular hemolysis pathogenesis

Back 268

1. Molecular mimicry and breakdown of peripheral tolerance
2. IgM Antibody is generated against RBC membrane components
3. Results in intravascular hemolysis mediated by complement

Front 269

Familial Predisposition to IMHA

Back 269

-American Cocker Spaniels (VERY common)
-Poodles
-Females 3-4x more common than males
-Young-middle aged dogs2-8 years
-Can be acute or chronic

Front 270

Diagnosis of IMHA

Back 270

-Hx, clinical signs
-CBC: regenerative anemia, macrocytosis, polychromasia, ansiocytosis
--can see concurrent immune-mediated destruction of platelets
-Chemistry Screen: bilirubinemia,
-Urinalysis: bilirubinuria, hemoglobinuria (with intravascular hemolysis)
-Autoagglutination
-Spherocytosis
-Positive coomb's test

Front 271

Direct coombs' Test

Back 271

-Used to diagnose IMHA
-RBC has antibody on surface
-Incubate blood sample with Coomb's reagent (antibody against antibody)
-Agglutinates RBCs

Cannot do test in patients if dog is already auto-agglutinating

Front 272

Indirect Coombs' Test

Back 272

-Identifies antibody to RBCs in serum
-Can tell difference between true autoimmunity and something foreign on RBCs
--true autoimmunity will have antibody in serum
-Patient's serum is incubated with RBC from unaffected dog (dog must have same blood type)
--if antibody is present, will attack RBCs from unaffected dog
--Add Coomb's reagent and see if agglutination happens

Front 273

Treatment for AIHA/IMHA

Back 273

1. Remove inciting cause (other drug, infectious etiologies, neoplasia)
2. Immunosuppressive doses of corticosteroids
--inhibit Fc receptor recognition of antibody
--decreases phagocytosis of sensitized RBCs
--interferes with antibod binding to RBCs
-Will not have an effect on auto-antibody production
3. Additional immunosuppressive agents
4. Splenectomy in severe cases, remove sensitized RBCs
--Only useful if antibody is to IgG

Front 274

Thrombocytopenia

Back 274

-Same process as IMHA, but cell that is attacked is a platelet
-Antobody and complement mediated platelet phagocytosis in the spleen and liver, destruction of megakaryocytes in bone marrow
-Antibody is directed against platelet antigen or exogenous antigens
-May occur alone or with IMHA
-Get spontaneous hemmorhages, can bleed into GI or into brain in platelet count is really low

Front 275

Evan's syndrome

Back 275

-ITP and IMHA
-No RBCs and no platelets

Front 276

Clinical signs of ITP

Back 276

-Spontaneous bleeding, bruising, ecchymoses, low platelet count
-Platelet count below 20,000 leads to spontaneous bleeding
-Bone marrow aspirate shows megakaryocytosis
-No good diagnosis

Front 277

Myasthenia Gravis

Back 277

-Autoimmune disease
-Characterized by autoantibody directed against ACh receptors on post-synaptic membrane of neuromuscular junction
-Associated with thymic hyperplasia, thymoma
-Antibodies bind to ACh receptors and block them
--cannot see ACh, ACh cannot interact with the receptor, no signaling
-Interaction between receptor and antibody leads to endocytosis of receptor
-inflammation of post-synaptic membrane
-no effective ACh signaling
-Surface area of membrane decreases as receptors are taken in

Front 278

Autoimmune and Immune mediated skin-disease

Back 278

-Autoantibodies are directed at intracellular cement holding epidermal cells together or at basement membrane
-immune complex formation results in complement activation and induction of inflammation
--big inflammatory response
--results in damage to surrounding tissues
-Characterized by vesicle and bulla formation
--vesicles= small, bulla= big
-Dx: skin biopsy, histopathology, immunofluorescence

Front 279

Pemphigus Disease

Back 279

-Immune-mediated skin disease
-Autoantibodies are directed against intracellular cement
-Vesicles are in epidermis
--more superficial and not as dangerous (uncomfortable, not deadly)

Front 280

Bullous Pemphigoid

Back 280

-Immune mediated skin disease
-Antibody is directed at basement membrane
-Vesicles in dermis, deeper
--deeper location, more dangerous disease

Front 281

Pemphigus Diseases

Back 281

-Presence of autoanitbodies to antigen in intracellular space between epidermal cells
-Immune system destroys glue between cells
-Formation of acanthocytes, epidermal cells are no longer connected to other cells
-Types:
--Pemphigus vulgaris (just above dermal/epidermal junction)
--Pemphigus Vegetans
--Pemphigus Foliaceous (antibodies against "glue" cells)
--Pemphigus erythematosus (superficial)
-Presence of IgG antibody alone is enough to induce acantholysis
--release of proteinase

Front 282

Locations of Pemphigus Lesions

Back 282

1. Pemphigus Vegetans: generalized distribution without mucosal involvement
2. Pemphigus Erythematosus: crusting around eyes and nose
--lesions exacerbated by sunlight
--Systemic signs are rare
3. Pemphigus Foliaceous: most common
--lesions on head and ears, then become generalized
--hyperkeratotic foot pads
4. Pemphigus Vulgaris:
--Acute or chronic lesions on mucocutaneous regions and nail beds
--Very painful

Front 283

Diagnosis of Pemphigus Diseases

Back 283

-Direct immunofluorescence: shows presence of IgG and C3 on epidermal cell surface
--antibodies surround acanthocytes and light up with fluorescence
-Circulating IgG may be present
--reacts with cell surface of stratified squamous epithelium in target substrates

Front 284

Bullous Pemphigoid

Back 284

-DEEP ulcerative lesions on mucous membranes and mucocutaneous junctions
-Relatively common
-Looks clinically similar to pemphigus vulgaris
-Circulating IgG binds to bullous pemphigoid antigens at demal/epidermal junction
-Linear alignment of IgG and C3 at dermal-epidermal junction (no honeycomb pattern)
-Antibody, complement inflammatory cells and proteolytic enzymes contribute to lesions and separation of dermis from epidermis
-NO acantholysis

Front 285

Treatment of autoimmune skin disease

Back 285

-Immunosuppressive therapy
-Prednisone to start
-Can add more immunosuppressive agents if needed
--azathioprine, cyclophosphamide
--gold salt therapy
-Bacteriocidal therapy for secondary bacterial infections

Front 286

Systemic Lupus Erythematosis

Back 286

-Chronic Multi-system inflammatory disease
-waxing and waning course
-Abnormal immune system hyperactivity and production of multiple autoantibodies
--Antinuclear antibodies
--Anti double-stranded DNA
--Antibodies against numerous non-nucleic acid antigens
-Immune complex mediated type III hypersensitivity
--immune complex final location shows inflammation
-Signs can be very varied, making it hard to diagnose this disease
-Severity of the disease depends on where immune complexes form

Front 287

Lupus signs and diagnosis

Back 287

-Serum complement levels are reduced
-Immune complex deposition occurs in vasculature, joints, skin, glomerular basement membrane of the kidneys, on RBCs and platelets
-Immune complexes fix complement and leads to damage of surrounding tissues
-Damage is due to bystander effect
--cell that is damaged is not the target of the antibody itself

Front 288

Lupus Predisposing Factors

Back 288

-Genetic predisposition, certain HLA types
-Age of onset= 6 years
-Predominantly in females with exacerbations during pregnancy
-infection leading to molecular mimicry?
-Defects in suppressor T-cell activity is present in lupus patients
--cause and effects are unknown

Front 289

Lupus

Back 289

Antibodies against nuclear components

Front 290

Autoreactive T-cells of one specificity can support the production of autoantibodies against multiple nuclear components

Back 290

T-cells with autoreactivity can support antibodies against body in other T-cells
-Can recognize any part of the nuclear complex (nucleosome, DNA, histone)
-T-cell can recognize one part and B-cell can recognize a different part

Front 291

Lupus Clinical signs

Back 291

-Can be anything, wherever immune complexes go signs will appear
-Fever, weight loss, lethargy
-Can be sudden onset or slow onset
-Waxing or waining
-Every organ system may be involved
-Shifting limb lameness, stiff gait, affected joints, arthritis, pleuritis, pericarditis, glomerulonephritis

Front 292

Lupus Diagnosis

Back 292

-Difficult in most cases
-based on clinical signs
--2 major clinical signs and one minor sign
--two minor signs and serological evidence
-Clinical results: Positive anti-nuclear Antigen test
--antibody response against nuclear antigens
-Tissue immunofluorescence

Front 293

Anti-Nuclear Antigen Test

Back 293

-Indirect immunofluorescence to detect circulating antinuclear antibodies in patient's serum
-ANA binds to nuclei of cells
-Presence of bound ANA is detected using immunofluorescence
-Can see deposition of immune complexes in kidneys or skin

Front 294

Lupus Treatment

Back 294

-Antiinflammatory agents: aspirin in less severe cases
-Corticosteroids: systemic, used in more severe cases
-New approaches:
--tolerance induction
--prevention of consequencesof pathogenic autoantibody production

Front 295

Endocrine Diseases Caused by autoimmunity

Back 295

-Hypothyroidism
-Hypoadrenocorticism
-Insulin-Dependent Diabetes Mellitus

Currently treated by replacement of hormones deficient as a result of destruction of endocrine glands
-just give missing components

Front 296

Initiation of Autoimmunity via class II expression

Back 296

-Non-specific infection or inflammation causes INF-g release
-Leads to aberrant expression of MHC class II molecules
-T-cells that recognize MHC class II are activated
-T-cells come and kill gland

Front 297

Rheumatoid Arthritis

Back 297

-Autoimmune joint disease
-Severe, erosive, progressive polyarthritis
-Mainly affects peripheral joints (carpus and tarsus)
-Chronic, progressive symmetrical polyarthritis
-Soft tissue swelling around joints
-Joints are very painful
--in advanced cases joint destruction and ankylosis/fusion can occur
-may have a genetic component

Front 298

Rheumatoid Arthritis Infectious Agents and genetic background

Back 298

-Infectious stimuli may initiate disease in genetically predisposed individuals
-High antibody titer to CDV and CDV proteins can be found in synovial fluids in joints
-Autoantigen may be IgG or collagen

Front 299

Rheumatoid Factor

Back 299

-IgGs have bound antigen and undergone conformational change
--exposes hidden epitopes
-Can be found in other diseases (lupus, osteoarthritis)

Front 300

Pathogenesis of Rheumatoid Arthritis

Back 300

-T-cell mediated disease, type IV hypersensitivity
-T-cells in synovial membrane
-Macrophage and cytokine production and formation of new blood vessels in connective tissue of joints
-IL1, IL6, GM-CSF, TNF-a cause fever
-C5a, PAF, attract neutrophils to synovia
--release proteases and free radicals
--degrade articular cartilage and ligaments
-Joints are painful, swollen, synovial proliferation (pannus)

Front 301

Rheumatoid Arthritis Diagnosis

Back 301

-Morning stiffness
-Pain on joint movement
-Soft tissue swelling
-Swelling in at least one other joint within 3 month period
-Symmetrical joint swelling
-Consistent radiographic findings
-Presence of rheumatoid factor
-Characteristic synovial and nodule histology

Any 5 signs must be present for at least 6 weeks
ANA test must be NEGATIVE

Front 302

Rheumatoid Arthritis and Synovial thickening

Back 302

-Should be a thin layer
-With RA, is much thicker and inflitrated with lymphocytes and plasma cells
-Increased collagenous connective tissue-

Front 303

Test for Canine Rheumatoid Arthritis

Back 303

-Similar to Coombs test
-Incubate canine serum against sheep erythrocytes
--get covered in canine antibody
-Add patient's serum
-If RF is present, will agglutinate and clump

Front 304

Significance of positive Rheumatoid Factor

Back 304

-Not very specific
-Found in serum, joint fluid
-Should be positive in joint fluid to give conclusive diagnosis
-Titer greater than 1:16 is significant, occurs in 70% of RA dogs
-lots of RF in joint fluid tends to correlate to severity
-Some patients with RA do not have any RF, some with RF do not have any arthritis
--have to put whole picture together!

Front 305

Rheumatoid Arthritis Treatment

Back 305

-Control pain and slow progression of the disease
-NSAIDs
-Steroids
-Immunosuppressives (cyclophosphamide, cyclosporine)
-Antibodies to TNF-a, CD4, IL2r

Suppress the immune response

Front 306

Tumor Immunology

Back 306

-Study of antigenic Properties of transformed cells and host's response to transformed cells
-Immunological consequences to host of having a tumor
-how immune system can be manipulated to recognize and destroy transformed cells

Front 307

How do cells become Cancerous

Back 307

-Spontaneous transformation
--random mutations
--gene rearrangements, chromosomal translocations
-Induced transformation
--chemical carcinogens
--Physical carcinogens
--Viral carcinogens

Front 308

Chemical Carcinogens

Back 308

-Induced transformation
-Polycyclic armoatic hydrocarbons
-Aromatic amines in dyes

Front 309

Physical Carcinogens

Back 309

-Induced transformation
-X-rays and radioactivity
-UV light

Front 310

Viral Carcinogens

Back 310

-induced transformation
-DNA viruses
--herpesvirus, adenovirus
--Integration of viral DNA into host genome
-RNA viruses

Front 311

Common properties of Tumor Cells

Back 311

1. failure to respond to regulatory signals for normal growth and repair
--grow autonomously
2. Grow without exogenous growth factors
3. Invasive growth through normal tissue boundaries
4. Metastatic growth, spreads to distant organs
5. Monoclonal origin, genetically unstable
--mutate all of the time
6. Have differences in appearance and membrane antigenic display from non-transformed cells of the same tissue origin

Front 312

Tumors are Immunogenic

Back 312

-Produce an immune response
--can be good and bad
-CD8 cytotoxic T-cells can eliminate tumors
-Can be a form of therapy for tumors

Front 313

Immune Surveillance and tumors

Back 313

-Immune system controls outgrowth of cancer cells
--eliminates cells bearing malignant mutations
-Animals that are immunodeficient tend to have more tumors
-Tumors can develop in immunologically privileged sites
-Immunological response will cause tumor to change

Front 314

Changes in tumor in response to immunological pressure

Back 314

-Tumor will change to get away from immune system
-Tumor antigen escape variants exist
-Other tumor cells will take over the population
-With therapy, want to target a cell that the tumor cannot get rid of
--telomerase

Front 315

Tumor Antigen-specific t-cells

Back 315

-Present in tumor-bearing hosts
-Patients with CD8 T-cells that have infiltrated tumor tend to have a better prognosis than patients with regulatory T-cell infiltration or few CD8 T-cells

Front 316

INF-g and lymphocytes in tumor control

Back 316

-Important in controlling tumors
-Immune response will kill all tumor cells it can see
-Will develop a tumor population that is "invisible" to the immune system
--issue for immune therapy
--can be very dangerous
-No interferon response, no ability to amount an immune response
--no defense against cancer

Front 317

Tumors developed in mice that cannot immune edit

Back 317

-No immunological response against tumor
-When out into wild-type mice, immune system will kill tumors
-Immune system interacts with the tumor and kills it

Front 318

Schreiber's Mouse Tumor experiment

Back 318

-Tumors that arise in lymphocyte deficient mice are more immunogenic than those that develop in the presence of an immune system
--do not have any pressure from immune system to develop
-Tumors that do continue to grow have avoided immune system surveillance

Front 319

Immune Surveillance

Back 319

-Elimination: immune system kills abnormal cells it can see
-Equilibrium: immune system cannot see all cells
--remaining cells can replicate
-Escape: Tumor is invisible to immune system
--Tumor can coerce immune system, employ T-reg cells to make immunosuppressive environment
--immune system cannot do anything

Front 320

Alternative model to immune surveillance

Back 320

-Immune suppressive cells come in early in process

Induction → inflammation →immunosuppression→immune privilege

Can produce as many CD8 T-cells as you can, but will be battling tumor

Front 321

What tumor antigens does immune system recognize?

Back 321

-Want tumor to express unique antigen, does not always happen
-Tumor associated antigens: found on tumor cells and some normal cells
--qualitative or quantitative differences to tell normal vs. tumor cells

Front 322

Unique Tumor-specific antigens

Back 322

-Found only on tumor cells
-Ideal targets for immunotherapy
-Ras mutations (seen in 10% of carcinomas)
-Bcr/Abl rearrangements (chromosomal translocation)
-Products of mutated tumor suppressor gene
--p53

Front 323

Tumor Associated Antigens

Back 323

-Found on tumor cells AND normal cells
-Qualitative and quantitative differences allow distinction between normal and abnormal

Front 324

Mutated normal gene antigens

Back 324

-Protein products of mutated genes can be expressed on tumor cell surface by MHC I
-Mutation may lead to protein that is different enough to be recognized by CTLs as foreign
--is targeted

Ex: abnormal mucins on surface of tumor cells
-in cancer cells, are under-glycosylated and reveal peptides on surface of the mucin
-target peptides by antibodies in immunotherapy

Front 325

Differentiation Antigens

Back 325

-Used to diagnose cancer
-Found in blood
-Normally only expressed at certain stages of cell differentiation
--during embryogenesis
-Expression outside of embryogenesis is abnormal, sign of cancer
-Carcinoembryonic Antigen (CEA)
-Alpha Fetoprotein (AFP)

Front 326

Carcinoembryonic Antigen
CEA

Back 326

-Member of immunoglobulin superfamily that is expressed normally in fetal gut, pancreas, and liver
-Acts as intracellular adhesion molecule in colon cancer
-Readily shed from tumor cells and serum
-Levels can be monitored in non-fetal patients to determine cancer presence and recurrence

Front 327

Alpha Fetoprotein
AFP

Back 327

-Protein normally expressed in embryos, but can find in carcinomas as well

Front 328

Over-expressed antigens on tumors

Back 328

-Normal antigens that are over-expressed on the tumor cell surface
-Gene products normally expressed at low levels, but expressed at high levels in tumors
-MAGE: found in carcinomas of the lung, liver, stomach, esophagus, urinary bladder
-Tyrosinase: target of canine melanoma vaccine
--involved in production of melanin and melanocytes
-Prostate-specific antigen
-HER-2/neu: Epidermal growth factor receptor
--expressed on breast cancer cells
--Associated with 40-50% of human and canine osteosarcomas

Front 329

Canine Mammary Carcinoma

Back 329

-35% of mammary tumors are Her2/Neu positive
-Malingnant tumors can use vaccination for metastatic tumors that express Her2/neu

Front 330

Oncogenic Viral Antigens

Back 330

-Viral antigens result from protein produced by the infecting virus
-Virus infects cell and produces viral particles
-Induces immune responses due to expression of non-self antigens

Ex:
-Epstein barr Virus
-HPV

Front 331

Types of Tumor Antigens

Back 331

1. Product of oncogene or mutated tumor suppressor gene
2. Mutated self protein
3. Over-expressed or aberrantly expressed self-protein
4. Oncogenic virus

Front 332

Locations of Tumor Antigens

Back 332

-Have MANY cellular locations
--on surface, in tumor, in nucleus, presented by antigens, secreted

Front 333

Identification of Tumor Antigens

Back 333

1. purify mononuclear cells from tumor site
-isolate T-cells present, presumably have specificity for tumor antigens
2. Isolate t-cells away from the tumor
3. Put CD8 T-cells and tumor together
-will develop CD8 T-cells that can react to specific tumor
4. Take RNA out of melanoma cell line and make cDNA library
5. introduce T-cells to cell types with different cDNA libraries
-find which T-cell clone kills which gene sequence
-Which cells can be targeted

Front 334

Biochemical approach to tumor antigen

Back 334

-Identify tumor by eluting tumor specific peptides from purified MHC class I molecules from tumor cells
-MHC class I molecules are isolated from tumor cells
--treated to elute bound properties
-Peptides are fractionated, fractions are tested using surrogate target cells for lysis
-Take cells and cut out MHC class I, take antigen off of receptor, and find out what antigen is

Front 335

Human Tumor Antigens

Back 335

1. mealnoma:
-antigen: tyrosinase, trp-1, trp-2
-antigen tissue specific
2. Cervical cancer:
-antigen: HPV-16, E6, E7
-Transforming virus gene
3. 50% of all human cancers
-Antigen: p53
-Mutated oncogene

Front 336

Effector Mechanisms that Kill Tumors

Back 336

-CD8 T-cells, cytotoxic T-cells
-Humoral Immunity and antibodies
-Natural Killer Cells
-Innate Immunity

Using all can be used for active and passive immunotherapy

Front 337

Humoral Effector mechanisms for Tumor suppression

Back 337

-Down-regulate cell-surface oncogene products
--results in a loss of transforming phenotype
-Mediate through Fc receptors on macrophages and NK cells
-Only effective against cell surface expressed antigens
-Retoximab: B-cell lymphomas and leukemias
--targets CD20
--CD20 exists on all B-cells, not just tumor B-cells (results in immunosuppression)

Front 338

Monoclonal antibodies and targeted therapy

Back 338

-Anti CD20
-Kills B-cells
-No antibodies, no antibody response to rituximab
-Only works for targets on surface of the cell
-Extremely costly, $80,000 per year
-Antibodies are currently not canine, are only for mice or humans
--different antibodies, body will attack as foreign antibodies

Front 339

Adaptive T-cell immune response to tumor-associated antigens

Back 339

-Convince immune system that tumor is foreign
-Tag for destruction
-Induced immunological response against tumor pathogen
-Create some level of "Danger" so immune system responds

Front 340

CD8 T-cells and Cancer

Back 340

-Provide effective anti-tumor immunity in vivo in many mouse tumor models
-Cytotoxic T- Lymphocyte repsonses against tumor antigens occur in human peripheral blood
--correlate with a better recovery
--Can use as an assessment for whether therapy is working
-Found in human, canine, and mouse tumors
-CTLs will go in against specific antigens and will start to kill them off
-Will get inflammation and epitope spreading, get immunological response against different parts of the tumor
-Have to get CD8 cells into tumor and get rid of T-reg cells
-CD8 cells will only kill something that is presented by MHC class I

Front 341

Rituximab and antibodies

Back 341

-Rituximab wipes out all antibodies and B-cells
-Cannot mount same immune response, may be able to use in therapy where normally would be tagged as foreign and eliminated

Front 342

Tumors and MHC class I

Back 342

-CD8 can only kill cells that have antigen presented on cell surface by MHC class I
-Tumor will down-regulate MHC I
--cells that do not use MHC I will survive more effectively
--becomes "invisible" to immune system
-BIG issue for CD8 recognition!
-NK cells may be able to kill this population
--target cells that do no express MHC I

Front 343

CD4 T-cells and cancer

Back 343

-Provide help
-Recognition of antigens in context of MHC II activates CD4 cells and cytokine production
-Cytokines:
--IFN-g: activates macrophages and NK cells to kill tumor
--TNF-a: initiates apoptois in cancer cells directly
--Interleukins support humoral immunity
--support CD8 response
-FasL killing
-IFN-g is angiogenesis inhibitor, prevents tumor growth

Front 344

Tumor Angiogenesis

Back 344

-Tumors need bloodflow to grow
-Cut off blood supply, no tumors grow
-IFN-g will inhibit angiogenesis by inhibiting vascularization

Front 345

Innate Immune Responses and Cancer

Back 345

-NK cells, Myeloid cells, cytokines
-Inject tumors with bacteria to initiate innate immune response
-Toxins are added to stimulate immunological response

Front 346

Coley's Toxins and Potential Mechanisms

Back 346

-Toxins act as adjuvant for tumor specific therapy
--mixed with autologous tumor cells
-Some bacteria are known to infiltrate and reproduce in tumors
--will cause an immune response in tumor cells that contain bacteria
-Stimulates macrophages to secrete TNF, IL12, and cytotoxic cytokines for systemic effects

Front 347

Bacterial PAMPS and cancer

Back 347

-Are particularly good at activating TLRs
-Can act on a number of TLRs
-Act as immune stimulants

Front 348

Natural Killer Cells and Tumors

Back 348

-Go after cells with low expression of MHC class I, often tumor cells
-Activity can be enhanced by cytokines IL2, IFNs, and TNF
-Contain 2 types of receptors on membrane
--killer inhibitory receptors
--Activating receptors

Front 349

Killer Inhibitory Receptors on NK cells

Back 349

-Dominant type of receptor
-Receptor binds to class I molecules and activate receptor
-Activated receptor sends negative signal to NK cell
-NK cell is prevented from killing the target

Front 350

Activating receptors on NK cells

Back 350

-Bind to ligands on the surface of a target cell
-Activated receptor sends positive signal to NK cell
-NK cell kills target cell

Front 351

Mechanisms of NK cell killing

Back 351

1. Degranulation: granules in NK cell contain perforin
--puts holes in surface of the target cell
2. Fas-Ligand: NK cell surface FasL binds to Fas on surface of target cell
--Initiates a signal that passes through target cell to induce apoptosis
3. INF-g production: activates macrophages and NK cells

NK cells go after MHC I deficient cells

Front 352

Tumors are poorly immunogenic

Back 352

-Tumors are "self" and poorly immunogenic
-down-regulate MHC I molecules on cells
--unrecognizable by CD8 cells
--NK cells can recognize
-No expression or low expression of co-stimulatory molecules
--T-cell will be anergized
-Tolerance in CD4 cells, cannot help CD8 population
-Escape system of evolution

Front 353

Tumors are immunosuppressive

Back 353

-Can generate T-cells, put antibody on the surface of a T-cell
-Expression of inhibitory molecules (IL10, TNF-g, FasL)
--leads to inhibition and/or apoptosis of T-cells entering tumor
-Defective antigen processing in APCs

Front 354

Mechanisms of Tumor Evasion

Back 354

1. Tumors are poorly immunogenic
2. Tumor microenvironment is immunosuppressive
3. Tumors grow rapidly and mutate frequently
4. Tumors have immune-specific factors

Front 355

Tumors grow rapidly and mutate frequently

Back 355

-Numbers game
-Rapid growth and bulky disease
-Tumor growth can be faster than CD8 cell activity
-Mutations may lead to antigenic variant that is not recognized

Front 356

Immune specific factors in Tumors

Back 356

-Tumors are self, can generate tumor-specific T-cell tolerance
-Have to "break tolerance" to kill cells
-lack of "danger" signals associated with tumors
-Presence of T-reg, myeloid suppressor, tumor-associated macrophages inhibit immune response
-Intrinsic defects in T-cell signaling pathways

Front 357

Tumor escape from immunne responses

Back 357

-As a consequence of mounting an immune response to a tumor, you will eventually produce a tumor that is "invisible" to the immune system
-

Front 358

Approaches to cancer immunotherapy

Back 358

-increase tumor specific t-cells
-Non-specific activation of the immune system
--convince body that the tumor is dangerous

Front 359

Non-specific activation of the immune system

Back 359

-BCG mycobacterium extract
--has immune-stimulating properties
-Can be taken up by macrophages and leads to activation
-Macrophages can take up dying tumor cells and initiate immune response
-Effective in treating bladder cancer in humans (not dogs)

Front 360

Strategies to generate and enhance tumor specific T-cell immunity

Back 360

-Active immunotherapy, actively immunizing patient to stimulate immune response
-Passive therapy, generate everything outside of patient then put back in
--Effective due to defects in APCs or T-cells, maybe associated with environment
-Can non-specifically expand T-cells out of the body and put back in to battle cancer

Front 361

Promoting tumor-specific T-cells

Back 361

-Activation and expansion
-Expand cells that are specific for the tumor
-Grow cells on APCs
-Have to figure out how to get T-cells into body without causing an immune reaction
-Supply Patient with anti-tumor antigens and stimulate APCs

Front 362

Autologous and Allogenic whole tumor cell vaccines

Back 362

-Autologous= from patient
-Allogenic= from someone else
-Can give to patient and have them taken up by APCs
-Will cause a reaction within the host
-Give whole tumor cell, all antigens possible
-Can modify to secrete pro-inflammatory cytokines

Front 363

Steps in Autologous and Allogenic whole cell tumor vaccines

Back 363

1. Take irradiated tumor cells and inject into Pt
2. Tumor cells are taken up by host APCs
--transported into lymph node
3. Will get priming in the lymph node
--can get cross-priming
--stimulates CD8 T-cells

Can also make a tumor cell look like a dendritic cell
-genetically modify tumor cell
-Will present all own antigens

MUST be safe and well-tolerated

Front 364

Tumor vaccine strategies in veterinary medicine

Back 364

-Target melanoma, responds the best
-Have to think about vaccine strategies
--timing
--frequency
--dose
--route of administration
--preconditioning regimes
Have to get rid of tumor micro-environment to be able to really assess vaccine strength and effectiveness

Front 365

Peptide and DNA vaccines

Back 365

-Not really seen in vet med
-Do not understand immunogenetics
-Peptides sit in MHC haplotypes
-DNA vaccines are against telomerase
--inject into body with a gene gun, protein will be produced and presented to stimulate an immune response

Front 366

APC based cancer vaccines

Back 366

-Want an APC that is "loaded" and ready to go with antigen
-Autologous therapy
-Can spin out WBCs and platelets, get bag of isolated monocytes
-Use monocytes to make a dendritic cell vaccine
-Dendritic cells do not proliferate, each time you want a monocyte population have to go through extraction procedure

Front 367

Adoptive Immunotherapy Transfer

Back 367

-Take t-cells out of the body
-Stimulate with magnetic beads coated with antigens, produce a large number of T-cells
--some will be specific to the tumor
-Put back into patient
-Artificial way to produce a large number of T-cells

Front 368

Pathogens

Back 368

-Prokaryotic cells are TINY compared to eukaryotic cells
-Viruses are TINY compared to prokaryotic cells and miniscule compared to eukaryotic cells
-Not all microorganisms are pathogens
-Carry a lot of viral genome within out own genome

Front 369

Pathogen-Host Interactions

Back 369

-We live in constant interaction with bilions of pathogens
--in food, air, everywhere
-Carry viral genomes in our own genetic material
-Carry viruses and bacteria as part of our microbiome
--fundamental for some organisms lifestyle

Front 370

Microbial Pathogens

Back 370

-Process of producing diseases
-Pathogen interferes with host cellular process
-Collateral damage of host defensive mechanisms
--tissue damage can be source of immune response

Front 371

Host barriers to infection

Back 371

1. Physical barriers
-common barrier to many different kinds of pathogens
2. Innate immunity
-a little more specific
3. Adaptive immunity
-specific response to pathogen

Front 372

Pathogen recognition receptors

Back 372

-TLRs, RLRs, etc.
--RigI-like receptors
-Receptors that are specific for virus molecular motifs
-Cover different cellular components and cell types
-TLRs are on endosomes
-RigI-like receptors are proteins that function as helicases in cell
--recognize RNA and DNA in cytoplasm

Front 373

Toll-Like Receptors (TLR)

Back 373

-On surface or on endosomes in cell
-Recognize specific motifs
-Will recognize genetic material of viruses

Front 374

RIGI-like receptors

Back 374

-RIG-I and MDA5
-Recognize viral RNA replicating in the
-Expressed on pretty much every nucleated cell in the body
-Same signaling process as TLRs
-Intermediate molecules cause transcription and translation activation

Front 375

Cytokines important in innate immunity
Type I interferons

Back 375

-Type I interferons: INF-beta and INF-alpha
-Hallmark of antiviral response
-Presence of INF-a and INF-b indicate recent viral infection
-Inhibit virus replication
-Prepare neighboring cells
-Support antigen presentation
-Signal to distal cells to become resistant to pathogen
-Pro0inflammatory molecules recruit and activate phagocytes
--prepare transition to adaptive immunity

Front 376

Type I interferons and virus spread

Back 376

-IFN-a and IFN-b prevent viral replication
-Essential to prevent spread of a virus
-Prevents neighboring cells from being able to replicate the virus
-Have control over antiviral immunity

Front 377

Antiviral inflammatory response

Back 377

-Involves IFN-a and IFN-b cytokines
-Also involves other cytokines

Front 378

Steps for IFN activity in cell

Back 378

1. Virus makes its way into the cell
2. RLRs identify viral genome in cytoplasm
3. Signal transcription of IFN
4. IFN acts on receptors that are present in pretty much all cells
--signals molecules to stimulate interferon-Stimulated Genes
5. Interferon-Stimulated Genes prepare cell for virus, allows fast immune response

Acts locally, at a distant, and on activated cell

Front 379

Activity of IFNs in Immunity

Back 379

1. Hallmark antiviral cytokine
2. Induce expression of genes with direct antiviral activity
3. Prime cells of the innate immune system to better respond to infection
4. Regulate various elements of the adaptive immune response
5. Used as anti-viral therapy in chronic infections

VERY important!

Front 380

Cytokines expressed in lung after infection

Back 380

-Takes animal 2 days to produce interferons and cytokines
-After about 10 days infection is over and cytokines decline
-recruit other cells to site of infection

Front 381

Other cells recruited to the site of infection

Back 381

-Recruit innate response cells
-Phagocytes (macrophages, neutrophils), NK cells
--eliminate infected cells
-Professional antigen presenting cells
--dendritic cells

Cells are in environment that is filled with cytokines
-cytokines shape immune response of cells
-Cells migrate to lymph node to initiate adaptive immune response

Front 382

Overview of the Anti-viral Response

Back 382

1. Virus infection/detection by RLRs and TLRs in resident cells
--dendritic cells see virus and become activated
2. Production of cytokines and chemokines, recruits cells from the periphery
3. Dendritic cells capture antigen and become activated
4. Expression of cytokines and chemokines cause migration to the lymph nodes
5. Dendritic cell presents antigen to CD8, CD4, and B-cells in lymph node

Cycle takes 5-7 days, have an incubation period before you get sick

Front 383

Adaptive Immune Response to Viruses

Back 383

1. Antigen is presented in the draining lymph node
--B and T cells are activated by antigen presenting cell
2. T-cell mediated lysis of infected cells
--CD8 T-cells enter circulation and go to infected tissue, recognize viral peptides presented on MHC class I
--CD8 T-cells kill infected cell
3. Memory is established, provides protection from subsequent infections by the same pathogen
--neutralization by antibodies and quick expansion ad response by T-cells in future

Front 384

Viral Evasion of the Host Immune Response

Back 384

-Virus has to learn how to live in the body
-Mechanisms have evolved to evade innate immunity
-Encode antagonists of innate response, focus on blocking innate immune response
-Interfere with the adaptive immune response
-Will change, evade antibodies by changing too quickly
-Can integrate into the cellular genome

Front 385

Proteins encoded by viruses block specific steps in immune response

Back 385

-At each step of the immune response, have at least 5 different proteins encoded by virus that block step
-Blocking one step can have huge effects on immune response
-Allows viruses that are adapted to the host to be very efficient
-With zoonotic diseases, viruses have to change to interact with the host

Front 386

Zoonotic viruses

Back 386

-Have to adapt and change to be successful in a new host
-Change protein expression and how it deals with the host
-Immune system of host does not necessarily have mechanisms to defend against new virus proteins

Front 387

Flu NS1

Back 387

-Very efficient virus
-Blocks interferon
-Results in no immune response
-Only has 8 genes, 10 proteins
-Expresses protein NS1, blocks RIGI signaling
-If cell has antiviral genes or proteins, will not see virus at all
--body can combat virus efficiently

Front 388

Different viruses have different proteins and affect different parts of the immune system

Back 388

-For any given virus, will have a different sent of mechanisms and different effects

Front 389

Bacteria Infection

Back 389

-Strategy is to evade the immune system
1. Prevent phagocytosis
2. Evade complement
3. Impede function of lymphocytes and granulocytes
4. Antigenic Variation

Front 390

intracellular survival of bacteria

Back 390

-Some bacteria and parasites can live inside phagocytes
--mycobacterium tuberculosis, listeria monocytogenes, toxoplasma gondii
-Take control of replication cycle
-Avoid fusion of phagosome with lysosomes that contain antimicrobials
-Interfere with the function of the phagolysosome
-Escape form the phagolysosome to the cytoplasm

Front 391

Goals of immunization

Back 391

1. Avoid infection
2. Prevent spread of infection
3. Prevent clinical disease
4. Reduce clinical disease

Will never get full sterility

Front 392

Methods of Immunization

Back 392

1. Passive Immunity (short-term)
-transfer of pre-formed immunity, lasts as long as antibodies survive
-Natural: transfer of antibody from the mother
-Artificial: antibody therapy, administration of Ig, neutralization of toxins
2. Active Immunity: long-term
-Natural: infection
-Artificial: vaccination

Front 393

passive Immunity

Back 393

-Transfer of pre-formed immunity
-Short immunity, lasts as long as antibodies survive, temporary
-Host immune system does not need to make appropriate response
-Side effects: need repeated injections, can have adverse reactions

1. Natural: transfer of antibody from mother via colostrum
2. artificial: antibody therapy via administration of Ig or neutralization of toxins

Front 394

Active Immunity

Back 394

-Long-term immunity
-Host system is forced to make appropriate response
-Immunity is transferred to offspring

1. Natural: infection
2. Artificial: Vaccination
--aims to develop an immune response

Front 395

Passive Immunization methods

Back 395

1. Placental antibody transfer
--fetus is immunized with IgG from mother
--Provides protection to offspring in first months of life
2. Colostrum
--IgA, IgG, IgM are found in human milk
--exposure to antibodies for pathogens mother has already had
3. Antibody and Serum Therapy
--Antibodies raised in animals
--serum from recovering individuals
--monoclonal antibodies raised in the laboratory

Front 396

Vaccintion of neonates

Back 396

-Important to not vaccinate neonates!
-Maternal antibodies will neutralize vaccine and it will not have any effect

Front 397

Why Vaccinate?

Back 397

-Induces immunological memory without causing disease
-Will form memory to pathogen that will respond faster and more efficiently and specifically to secondary infection

Front 398

Impact of Vaccination

Back 398

-HUGE impact on health of individuals!
-Polio:
--increased coverage leads to decreased incidence
--amount of pathogen decreases
-Measles is the same
-Eradication of Rinderpest

Front 399

Veterinary Vaccines

Back 399

-1100 vaccines for animals
-79 for dogs
--core vaccines: canine distemper, canine adenovirus, parvovirus, parainfluenza, rabies
-60 for cats
--core viruses: panleukopeina, rhinotracheitis, calicivirus, rabies

Front 400

Approaches to vaccination

Back 400

-Many strategies
-Live attenuated organism
-Recombinant antigen

Front 401

Live attenuated Organism approach to vaccination

Back 401

-Not a vaccine directly, organism itself is used to create an immune response
-Organism is alive but will not grow efficiently
--has been modified to not create tissue damage
-Organism will induce immune response
-Alive but not fully functional

Front 402

related organism approach to vaccination

Back 402

-Can use a pathogen that is similar in one animal to create an immune response in another animal

Front 403

Other approaches to vaccination

Back 403

-Dead organism
-Purified antigen
-Recombinant antigen
-DNA vaccine (prepare plasmid that encodes a protein normally seen on a pathogen)

Front 404

What kind of immunity do you want with vaccine?

Back 404

1. Humoral: antibody production
--neutralize pathogen before they cause damage
2. Cellular immunity:
--trigger CD8 T-cells

Front 405

Live vaccine vs. Dead vaccine

Back 405

-Highly antigenic vs. less immunoenic, safer
-Few innoculations vs. requires boosting
-Prolonged humoral and cellular immunity vs. poor stimulation of cellular immunity, no CD8 cells
-No Adjuvant vs. needs adjuvant
-May have residual virulence and reversion vs. safer
-Can spread to unvaccinated animals vs. does not spread
-Difficult to store vs. easier to store and manipulate

Front 406

Adjuvants

Back 406

-Molecules used to enhance immune response
-Triggers immunological response
-Concentrate pathogen particles
-Added to dead/protein vaccines to enhance immunogenicity
-Ex:
--Alum
--monophosphoryl lipid A
--Freund's adjuvant
--Bacterial CpG motifs

Front 407

Adjuvant Action

Back 407

-Put antigen in contact with the immune system
-Influence the type of immune response to the antigen
-Stimulates the immune response against the antigen
-Stimulates the activation of dendritic cells
-Needed to "get system going"

Front 408

New approaches to vaccinations

Back 408

1. DNA vaccine
2. Living vectors (viral and bacterial)
--use genome to make protein to induce reaction
--want virus to go into one specific cell and activate PAMPS
--will never become a full virus, not all parts are present
3. Dendritic Cells as carriers
--take dendritic cells out of patient, infect, and put back in to cause immune response

Front 409

Route of vaccine Administration

Back 409

Route of administration matters!
1. Subcutaneous
2. Intradermal
3. Intramuscular
4. Oral in water or food (important route for animals)
5. Intranasal or aerosolized (common in brids)
6. Topical/transdermal
7. Immersion (common in fish)

Front 410

Considerations for route of vaccine administration

Back 410

1. Live vs. attenuated vaccine
--will go to different places in the body
2. Type of adjuvant and adverse reactions
--important for route of administration, different cells in different areas, different cytokines, etc.
3. Immunogenicity at different sites
--location of injection is based on type of adjuvant, types of cells adjuvant interacts with
4. Target immunity, mucosal vs. systemic
--mucosal, want IgA specifically

Front 411

Vaccine Schedule and Doses

Back 411

-Newborns are passively protected and should not be vaccinated
--maternal colostrum will neutralize vaccine
--puppies = 6 weeks
-Mother may be vaccinated during late pregnancy to protect offspring
-Multiple doses boosts immunological memory
-Dose to induce optimal immunity

Front 412

Multiple Doses of Vaccines

Back 412

-Boosts immunological memory
-Duration of memory depends on the nature of the antigen, adjuvant used, route of immunization
-Memory cells will expand in response to exposure
-Depends on antigen, antigen/adjuvant combination, and route of administration

Front 413

Minimal duration of vaccine and optimal immunity

Back 413

-Minimal duration of immunity is generally not taken into consideration
-Duration of immunity is based on MINIMAL data available, "better safe than sued"
-Is not affected by the weight or size of the animal
--immune systems are comparable from animal to animal

Front 414

Mixed Vaccines

Back 414

-Growing number of combination vaccines
-Easier to administer, only takes one injection
-Less suffering for animal, less cost for owner
-May be wasteful, vaccinate for something you don't need
-May compete for immunity
-NEVER MIX VACCINES!

Front 415

Immune Status of the host can affect vaccination outcome

Back 415

-Pregnancy
-Cancer
-Immunosuppressive Drugs
-Infection
-Primary autoimmune deficiencies
-Nutrition and stress
-Age

Vaccine will probably not work as well if any conditions are present

Front 416

Side effects of vaccines

Back 416

-Some animals can show specific side-effects to vaccines
-FeLV post-vaccine fibrosarcoma
-Granuloma formation
-Systemic reactions
--immediate anaphylaxis
--delayed allergic response
-Immune competent host disease signs
-Shedding virus
-Vaccine break or contamination

Front 417

Ethics of vaccines

Back 417

-DO we need all vaccines?
-Do we need frequent vaccinations?
-Is the immune system similar between species?
--currently know the most about mice
-Interests of consumers vs. veterinarians vs. vaccine producers

Front 418

Renal Transplantation Introduction

Back 418

-UC Davis was first successful transplant
-Renal function stayed normal throughout rest of cat's life
-Have patients that live up to 13 years post-transplant

Front 419

Factors that have made transplantation possible

Back 419

1. Cyclosporin use
--revolutionized transplantation
2. Ability to take an allograft from an unrelated donor
--understanding of immune response to foreign tissue
3. Microsurgical technique development

Front 420

Aspects of a successful transplant program

Back 420

1. Case selection
--really makes the difference
--not all cats or dogs are appropriate cases
2. Technical preparation and support
3. Equipment and facilities
4. Communication between client and referring vets

Front 421

What patients make the best recipients for renal transplant?

Back 421

-Whole picture of patient
-Early decompensated renal failure is best time to intervene
-Want a patient whose main problem is kidney disease
-recurrent UTIs are not good patients, infection will come back
-make sure patient can handle immunosuppression
-make sure patient does not have underlying cancer
-IBD does not make a difference
-Diabetes is kind of unknown, not enough info
-Animal should be able to take medication
-Fractious patients are not good patients
-No pathology associated with vasculature

Front 422

Infections and Renal transplants

Back 422

-Avoid infections!
-If animal is infected before procedure, will be difficult to maintain immunosuppression for transplant without incurring additional infections

Front 423

renal transplant Donors

Back 423

-Young, healthy cats
-Owner of recipient should adopt donor cat
-Dogs have to be very compatible, litter mate or relative
-Needs to be same blood type and cross-match compatible
--very important!
-CT angiography to look at donor kidneys
--can only have one arterial supply

Front 424

Preoperative care for renal transplant patients

Back 424

-Protein-restricted diet
-IV/sub Q fluid therapy
-Blood transfusions
-Hormonal therapy
-Medication for high BP
-Phosphate binders
-Dogs have local heparin to avoid clots after procedure

Front 425

Feline immunosuppression for renal transplant
Option 1

Back 425

1. Cyclosporine
2. Prednisolone
3. Azathioprine
--broad spectrum, not a lot of specificity
4. Other experimental
--many have side-effects

Front 426

Cyclosporine and Prednisolone in renal transplants

Back 426

-Cyclosporine: enters into cell and binds to cyclophilis ad inhibits calcinurin
--inhibits transcription of certain cytokines

Front 427

Feline immunosuppression for Renal transplant
Option 2

Back 427

-Combination of Cyclosporine, Steroids, and Ketoconazole
-Ketoconazole= antifungal agent
--inhibits cytochrompe p450 system
--level of cyclosporin stays higher for longer, decreases administrations and cost of medication
-Can cause hepatotoxicity in cats

Front 428

Canine immunosuppression for Renal Transplants

Back 428

-Cyclosporin and Prednisolone
-Lots of experimental protocols
-Lots of side-effects

Front 429

Anesthetic Management Primary Concers

Back 429

-keep patient warm
-Keep things sterile
-Try not to put in hind-leg catheters
--will not get venous return because vena cava is clamped off

Front 430

Donor Nephrectomy

Back 430

-Do not remove kidney from blood supply until totally ready
-needs to have a single renal artery
-Clean as much as you can before removal, do not want to clean under microscope
-Left kidney has longest vein
-Vein must be clean, especially to point of transection
-Cut ureter

Front 431

Surgical technique for Renal Transplant

Back 431

-Feline: anastomosis directly to aorta and vena cava
-Canine: anastomosis to ilia artery and vein
-Can clamp vessels, make windows that will match size of donor vessels

Front 432

Procedure for removed kidney before placed into recipient

Back 432

-Flush with heparinized saline solution
-Clean excessive adventitia
-Make sure vessels are not twisted

Front 433

Ureteral Anastomosis

Back 433

-Bilateral incision on bladder
-Pull ureter into urinary bladder and clean end
-Widen end and suture 360 degrees around

Front 434

Native Kidneys

Back 434

-Usually leave in body
-Want to get animal off table as soon as possible
-Sometimes graft does not work immediately, leave in just in case

Front 435

Enteroplication

Back 435

-Dogs with renal transplants commonly have intussusception
-Lay out bowel and suture to hold things together
-Keeps bowel from forming intussusceptions

Front 436

Postoperative Care for renal Transplants

Back 436

-IV fluids until eating and drinking
-minimal stress and handling, do not want to dislodge
-Broad spectrum antibiotics
-Pain control
-Monitor for seizure activity
-Dogs get blood thinners to avoid clots
-Take blood samples regularly
-Should see resolution of azotemia within a few days

Front 437

Vascular Pedicle Complications in renal transplants

Back 437

-Kidney is free-floating and has twister
-Artery thromboses very quickly
-needs re-transplant
-Can develop clots

Front 438

Ureteral Complications in renal transplants

Back 438

-Obstructions developed before suturing 360 degrees around
-Can have a stricture at site of anastomosis
--cut and re-attach

Front 439

Follow-up care for renal transplants

Back 439

-Weekly exams for first 6-8 weeks
-Decrease visits after cyclosporin has stabilized and other factors have stabilized
-Go in 3-4 times per year for monitoring

Front 440

Complications with Immunosuppression in Renal Transplants

Back 440

-Too little:
--allograft rejection or rupture

-Too much:
--Reactivation of latent infections
--Cancer
--Diabetes
--Poor wound healing

Front 441

Retroperitoneal Fibrosis

Back 441

-Patients develop fibrotic lesion in retroperitoneal space
-Encases urinary tract, causes mechanical obstruction
-Unknown cause
-Ureter is encased in scar tissue
-have to remove scar tissue to release obstruction

Front 442

Acute rejection of renal transplant

Back 442

-in cats, 13-26% rejection
-Usually occurs in first few weeks
-Cats will not act sick, will have subtle clinical signs
--might not notice very much
-Kidney will get big and bright on radiographs
-Inadequate immunosuppression
-May have infection

Front 443

Renal Allograft Rejection

Back 443

-Subcapsular and interlobar phlebitis
-Human scoring system does not work well for acute rejection, works fine for chronic rejection

Front 444

Allograft Rupture in renal transplants

Back 444

-Allograft rejection
-Kidney becomes edemetous and will rupture
-Due to infections

Front 445

Hemolytic Uremic Syndrome

Back 445

-Complication with chronic immunosuppressive therapy
-Toxic reaction to immunosuppressive drugs
-Throw clots
-Fatal for feline patients

Front 446

Gingival Hyperplasia

Back 446

-Common side-effect to renal transplant

Front 447

Infectious complications to renal transplant

Back 447

-Immunosuppressive therapy
-Bacterial infections are most common
-also have fungal and viral infections, some protozoal
-Develop infections in about 2.5 months
-2nd most common cause of death after allograft rejection
-Diabetes increases risk of complications

Front 448

Mycobacterial infections with renal transplant

Back 448

-Can cause joint infections

Front 449

T gondii infection

Back 449

-Toxoplasmic infection
-Totally detrimental for immunosuppressed cats
-Seropositive recipients are placed on lifelong prophylactic Clindamycin
-Cannot use seropositive donors for seronegative recipients

Front 450

Opportunistic infections in renal transplant patients

Back 450

-Cysts
-Fungal infections (not very common)

Front 451

Malignant Neoplasia and renal transplants

Back 451

-increased incidence
-Lymphoma is increased incidence with immunosuppression
-Can have decreased immune surveillance and neoplastic cell clearance
-Promotion of DNA mutations caused by drugs
-Activation of latent oncogenic viruses
--epstein-barr virus in humans

Front 452

Diabetes Mellitus and Renal transplants

Back 452

-Increased risk
-Cyclosporine and steroids are diabetogenic
-5.5x as likely to develop diabetes as non-transplant patients
-Taper immunosuppressive medication
-Give long-term insulin therapy

Front 453

Immunosuppression in Transplants

Back 453

-Prevention, not treatment should be the goal!
-Immunosuppressive drugs act indiscriminately
--suppress naive t-cells and memory T-cells

Front 454

Naive T-cells and allograft rejection

Back 454

-TCR is blocked, cell becomes anergic
--no co-stimulation
-For Naive T-cell to proliferate:
--naive T-cell must recognize antigen attached to MHC
--Co-stimulatory signal is necessary
--CD28 and B7 receptor must interact

Naive T-cell is important in allograft rejection
Memory T-cell is important in future interactions
-Want to inhibit Naive T-cell function and keep memory T-cells intact

Front 455

CTLA4

Back 455

-Receptor on memory T-cell
-Has affinity for B7 receptor (20x higher affinity)
-Immunoglobulin fusion protein
-Binding blocks T-cell proliferation and B-cell differentiation
--anergizes T-cells
-Prolongs transplanted organ survival
-Blocks graft vs. host rejection
-Prevents development of graft arteriosclerosis
-Induces allograft tolerance
--reduces long-term immunosuppressive therapy
-Inhibits T-cell dependent antibody responses

Front 456

CSFE

Back 456

-Fluorescent molecule taken up by cells
-As cells divide, intensity of fluorescence decreases
-more division and proliferation, decreasing intensity

Front 457

-Cyclosporin and CTLA caused decrease in CD4 T-cells
-Cyclospirin alone caused decrease in CD8 cells
-CTLA4 had more of an effect on CD4 cells

Back 457

-Cyclosporin and cyclosporin + steroids have a greater effect than CTLA-4
--Suppress CD4 and CD8

Novel drug causes significant decrease in CD4 cells, NOT CD8 cells
--CD4 cells are more co-stimulation dependent

Front 458

CTLA-4 and IL-10 suppression

Back 458

-CTLA-4 does not suppress IL-10
-Can be beneficial if IL-10 is involved in allograft suppression
-Causes suppression of all other factors (IL-2, IFN-g, GM-CSF) but NOT IL-10
-Sparing IL-10 can be significant
--can contribute to allograft survival

Front 459

Early identification of Acute graft rejection

Back 459

-Percutaneous needle biopsy
--invasive, has complications
-Want a non-invasive, early way to detect rejection
-Can look at blood and urine
-Distinguish between acute rejection and non-immunological causes of renal dysfunction