M9-4-07

Front 1

Define innate immunity.

Back 1

Innate: nonspecific immunity -a set of disease-resistance mechanisms that are not specific for a particular pathogen

Front 2

Give characteristics of innate immunity.

Back 2

1. Pre-exists infection or exposure to foreign antigen

2. Response occurs immediately after recognition of foreign organisms or substance

3. Does not confer protection against subsequent exposure to the same pathogen or foreign antigen

Front 3

Define Adaptive immunity.

Back 3

specific immunity, displays a high degree of specificity as well as the property of memory

Front 4

Give characteristics of adaptive immunity.

Back 4

1. Does not pre-exist initial exposure to a specific pathogen of foreign antigen

2. Requires 6-7 days to develop after initial exposure.

3. Confers memory - host is protected from subsequent exposure to the same organism

4. Secondary response is very rapid and effective

Front 5

What is the first line of defense just after the host's exposure to a pathogen?

Back 5

Innate immunity... most organisms are cleared by the non-specific innate immune response

Failure to clear an organism results in triggering of an acquired immune response

Front 6

Innate immunity is composed of how many defensive barriers?

Back 6

4

Front 7

What are the defensive barriers of innate immunity?

Back 7

1. Anatomic barriers - prevent entry of pathogens
-- Skin (outer epidermal layer and inner dermal layer)
-- Mucous membranes

Physiological Barriers - temperature, pH, and chemical mediators

Phagocytic barriers - ingestion of extracellular particulate material by phagocytosis

Inflammatory Barriers - tissue damage causes an inflammatory response

Front 8

What are two types of anatomical barriers?

Back 8

Skin - outer epidermal layer and inner dermal layer

Mucous Membranes

Front 9

Describe the dermis and epidermis.

Back 9

Epidermis - comprised of dead skin cells and keratin

Dermis - connective tissue, blood vessels, hair follicles, sebaceous glands, and sweat glands

Front 10

Describe the sebaceious glands

Back 10

produce oily substance called sebum and sebum contains lactice acid and fatty acids that inhibit bacterial growth

Front 11

What are the physiological barriers?

Back 11

Temperature
pH
Chemical mediators

Front 12

Describe how temperature acts as a physiological barrier?

Back 12

normal body temp inhibits grown of some microorganisms

fever response inhibits growth of pathogens

Front 13

Describe how pH acts as a physiological barrier.

Back 13

Low pH - the gastric secretions in the stomach maintain a low pH that kills most ingested organisms - skin also maintained at a low pH

Front 14

What are chemical mediators?

Back 14

1. complement: killing of microbes, opsonization of microbes, recruitment and activation of leukocytes.

2. mannose-binding lectin: opsonization of microbes, activation of complement

3. C-reactive protein: opsonization of microbes, activation of complement

4. Coagulation factors: walling off of infected tissues

5. Lysozyme: hydrolytic enzyme found in saliva and tears that cleaves the peptidoglycan layer of the bacterial cell wall

6. Interferon: group of proteins (cytokines) produced by virus-infected cells that induce an anti-viral state in adjacent cells and activates leukocytes

Front 15

Phagocytosis is primarily mediated by?

Back 15

neutrophils and macrophages that respond to the presence of an invading microorganism

Front 16

What cells are the first cells to reach sites of inflammation? What cells are the second to reach?

Back 16

NEutrophils

Macrophages

Front 17

Neutrophils vs. macrophages: which cells are longer lived?

Back 17

Macrophages are longer lived and have the ability to replicate and therefore play an important role in innate defense after the initial insult

Front 18

Describe the steps in phagocytosis.

Back 18

Cell's plasma membrane expands around particulate matter to form large vesicles called phagosomes, which fuse with lysosomes to form phagolysosomes where the ingested material is destroyed.

Front 19

What are the different types of inflammatory barriers?

Back 19

1. Vasodilation

2. Increased capillary permeability

3. Influx of phagocytic cells

Front 20

What are the 2 types of adaptive immune responses?

Back 20

Humoral immunity
Cellular immunity

Front 21

What is humoral immunity?

Back 21

immunity mediated by molecules in the blood called antibodies that are produced by B lymphocytes... specifically plasma cells

Abs recognize microbial antigens, neutralize the infectivity of microbes and target microbes for destruction.

Front 22

What type of immunity is the principle defense against extracellular microbes and their toxins?

Back 22

Humoral immunity

Front 23

What immunglobins promote phagocytosis?

Back 23

IgM

Front 24

What immunoglobins promote the release of inflammatory mediators from leukocytes?

Back 24

IgE

Front 25

What is cell mediated immunity?

Back 25

mediated by cells called T lymphocytes

promotes the destruction of cells harboring intracellular pathogens

Front 26

What is the difference between active and passive immunity?

Back 26

Active immunity is induced by exposure of the host to a foreign antigen - the host's immune system plays an active role in responding to the antigen
-- confers specificity
-- confers memory
-- is not immediate


Passive immunity - conferred upon the individual by transferring serum or lymphocytes from a specifically immunized person - person becomes immune w/o having been exposed to or having responded to antigen
-- confers resistance rapidly w/o having to wait for active response (6-7days)
-- confers specifity
-- does NOT confer memory

Front 27

What is the difference between passive humoral immunity and passive cell mediated immunity?

Back 27

Passive humoral - transferred by cell-free, Ab-containing protions of the blood--serum or plasma

Passive cell mediated - trasnferred with cells (T cells)

Front 28

What are the features of the adaptive immune response?

Back 28

1. Specificity
2. Memory
3. Diversity
4. Specialization
5. Self - limitation
6. Nonreactivity to self

Front 29

Describe B lymphocytes.

Back 29

B cells specifically recognize antigens by virtue of expressing unique antigen receptors on their surface -- membrane immunoglobulin

BCR - 2 heavy chains and 2 light chain polypeptides that are disulfided together

Binding of antigen to BCR leads to cell activation and entry into cell cycle

Front 30

What terminal end will you find the antigen binding sites?

Back 30

BCR = divalent

amino end

Front 31

Describe T lymphocytes.

Back 31

T cells express unique antigen receptors on surface that are comprised of 2 polypeptides (alpha and beta) that are disulfide linked

TCR recognizes antigen that is bound to either MHCI or MHCII

Have helper and cytotoxic T cells

Front 32

What is the difference between CD8 and CD4 T cells?

Back 32

Cd8 = cytotoxic, MHCI, recognize endogenous peptides

CD4= helper, MHCII, recognize exogenous sources

Front 33

Describe the action of helper T cells.

Back 33

Activation of helper T cells in response to antigen leads to proliferation and secretion of cytokines that promote activation of B cells and other T cells

Front 34

What is the difference between helper TH1 and TH2.

Back 34

TH1 = produce cytokines which support inflammation

TH2 = produce cytokines which promote B cell activation and development of immune responses that depend on Ab production

Front 35

Describe the function of cytotoxic T cells.

Back 35

Activation of cytotoxic T cells leads to proliferation and differentiation into cells that exhibit cytolytic activity

Front 36

What are the three types of APCs?

Back 36

macrophage
B cell
dendritic cells

These are MHC2 cells

Front 37

Describe the function of APC?

Back 37

APC first internalize antrigen either by endocytosis or phagocytosis, then process the antigen and display it on their surface bound to MHC Class II, which is recognized by the TCR on the helper T cell.

Front 38

What cells constitute the largest portion of WBCs that are circulating in the blood at any given time - most WBCs produced everyday are these subset?

Back 38

Neutrophils

Front 39

Do neutrophils die after they phagocytiza bacteria? macrophages?

Back 39

Neutrophils phagocytize bacteria and destroy them, killing themselves in the process.

Macrophages phagocytize bacteria and then present parts of the bacteria back out on their cell surface to communicate with (or induce) cells of the adaptive immune response.

Front 40

Where do macrophages come from?

Back 40

WBCs that circulate through the blood as immature monocytes and also migrate from the blood into challenged tissue and then differentiate into macrophages

Front 41

The local imnflammatory response is often mediated by a set of cytokines... name the cytokines.

Back 41

IL-1; IL-6; TNF-alpha

Front 42

If the cytokines are in high enough amounts, it can create a systemic response... describe the systemic response.

Back 42

1. increased temp
2. feedback on liver - produce more acute phase reactants (CRP, MBL, serum amyloid A (SAA), complement

3. feedback on bone marrow - bone marrow is site of hematopoiesis - increases the production of neutrophils in acute manner

Front 43

What are the 3 main players of the adaptive immune response?

Back 43

T cells
B cells
APCs

Front 44

Humoral immunity mainly deals with....

Back 44

extracellular microbes, parasites, and neutralizing toxins

Front 45

Describe the sequence of events in humoral immunity.

Back 45

Helper T cells produce cytokines which activate B cells.

B cells are the precursors to terminally differentiated plasma cells which secrete SOLUBLE proteins called Abs

Abs are the effectors in humoral response

Front 46

Cell mediated immunity mainly deals with...

Back 46

virally infected cells or cells containing intracellular bacteria

Front 47

Describe the sequence of events in cell mediated immunity.

Back 47

Helper T cells produce cytokines which can also differentiate cytotoxic precursor cells into cytotoxic T cells

Front 48

What is a major difference between cell mediated and humoral responses?

Back 48

Cell mediated - effector is a cell - T cell

Humoral - effector is a soluble protein = Ab

Front 49

What is agammaglobulinemia?

Back 49

Patients that have no B cells. Therefore, they have no Ab and must be given IV antibodies.

Front 50

Describe the antigen receptor found on B cells.

Back 50

the membrane immunoglublin has 2 heavy and 2 light chains joined by a disulfide bond.

Front 51

What are the two types of receptors found on T cells? Which one is more common?

Back 51

alpha-beta -- more common
gamma-delta

Front 52

T cell receptors only recognize.....?

Back 52

peptides either in the context of MHC2 or MHC1

Front 53

All cells on your body express which MHC class?

Back 53

one

Front 54

When is bradykinin released and what does it cause?

Back 54

It is released when you have physical insult to the skin.

It causes an increase in vascular permeability and vasculat dilation

Front 55

What is the role of fibrinopeptides?

Back 55

Acts as chemoattractant to attract phagocytic cells and

Front 56

What do each of the following receptors bind to and what is their fxn?

Complement
Mannose binding lectin
C-reactive protein
LPS binding protein

Back 56

Complement - binds to microbial cell wall components

Mannose - recognizes mannose on microbes - human mannose is always glycosylated by microbes isnt

C-reactive protein - bind to phosphatidylcholine in microbial membranes

LPS - recognizes lipopolysaccharide which is part of gram negative cell wall

each causes opsonization of microbes and activation of complement

Front 57

What does opsonization of microbes actually do?

Back 57

It puts a signal on the microbe surface that allows the phagocytic cells to more effectively bind to that microbe

Front 58

What is the lectin pathway in regards to the complement pathway?

Back 58

involves a situation where you have mannose binding lectin or c-reactive protein binding to a bacterium. This triggers the complement cascade

Front 59

What is the Alternative Pathway in regards to the complement cascade?

Back 59

A C3 component of complement would bind to the surface of a gram negative bacterium which provides an activating surfaces which allows the alternative pathway to be triggered

Front 60

What is the Classical Pathway in regards to the complement cascade?

Back 60

Ab molecules either IgM or certain isotopes of IgG bind to the surface of a bacterium and triggers the cascade

Front 61

What is C3a and C5a?

Back 61

Fragments of products of the complement cascade which are NAPHLOTOXINS

These bind to receptors on mast cells and cause mast cell degranulation. This causes factors to be released that increase vasodilation and increased vascular permeability

They are also chemotactic factors and promote recruitment of neutrophils to the site of the inflammatory response