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578 Cards in this Set

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True/False as pathogens became more complex so did the immune system.
TRUE
What type of immunity is described? Slow response (days to weeks), variable, numerous highly selective specificities, improve during response.
Adaptive immunity
List the four major components of the adaptive immune response.
1. Self vs non self recognition 2. Antigen-recognition molecules 3. clonal selection 4. memory
What type of immunity is termed the first line defense?
innate immunity
What type of immunity is described? Rapid response (hours); invariant; limited number of specificities; constant during response.
Innate immunity
Whih type of immunity is considered constitutive?
Innate immunity
Which type of immunity is considered inducible?
Adaptive immunity
Induction and control (in the form of tolerance/homeostasis) refer to what immunity?
Adaptive immunity
What are the three components of induction (in the adaptive immunity)?
1. Inducibility 2. specificity 3. clonality
True/False all cells in the immune system are white blood cells (leukocytes) and derive from the hematopoietic stem cell pool.
TRUE
Cell types associated with innate immunity are mostly from the _____________ lineage.
Myeloid
Cell types associated with adaptive immunity are mostly from the ___________ lineage.
Lymphoid
What are the two arms of the adaptive immunity?
humoral and cell-mediated
Which type of cell mediates the humoral adaptive response?
B cells
Which type of cell mediates the cell-mediated adaptive response?
T cells
Which arm of the adaptive immune response deal with extracellular pathogens?
Humoral adaptive response
Which arm of the adaptive immune response deals with intracellular pathogens?
cell-mediated
Differentiate between primary and secondary lymphoid organs.
Immune cell primordial development occurs in the primary lymphoid organs (thymus and bone marrow) whereas immune cell education occurs in the secondary lymphoid organs.
List four secondary lymphoid organs.
Spleen, tonsils, lymph nodes, and peyer's patches
How are the secondary lymphoid organs further divided?
Mucosal and systemic
Describe the function of mucosal secondary lymphoid organs.
Protect against pathogens attacking the mucosa
List the four 'eyes' of pathogens (multiple routes of entry).
Ingestion, Inhalation, injection, insemination
Waldeyer's ring (lymph nodes, tonsils and adenoids), bronchus-associated lymphoid tissue, lamina propria, peyer's patch and urogenital lymphoid tissue are all examples of which division of the secondary lymphoid tissue?
Mucosal
Lymph nodes, spleen, amd mesenteric lymph nodes are all examples of what division of the secondary lymph nodes?
Systemic
The _______________ lymphoid organs serve as filters across the blood, lymph & intestines.
Secondary lymphoid organs
Granulocytes are from what lineage?
Myeloid
True/False: T cells form germinal centers inside the lymph node.
False! B cells form the germinal centers in the lymphoid follicle.
Are the T cell areas deeper (toward the medulla) of the lymph node than the lymphoid follicle?
Yes the are under the lymphoid follicle and the germinal center.
List the five classes of infectious agents.
1. Viruses 2. Fungi 3. Bacteria 4. Parasites 5. Prions
What infectious agent? Smallest infectious particle; DNA or RNA based (only one class has both); components enclosed in a protein coat with or without lipid membrane; true parasites; require host cells for replication.
Virus
What infectious agent? Univellular prokaryotes; 1-20 microns; different shapes; divide by binary fission (assexual); Gram +/-.
Bacteria
What infectious agent? Eukaryotic organisms; two forms asexual and sexual; dimorphic (asexual/sexual)
Fungi
What does dimorphic mean?
Can reproduce by either sexual or assexual means
What infectious agent? Complex eukaryotes; some unicellular, others multicellular; can range in size from tiny protozoa to 10 meter tapeworms.
Parasites
What infectious agent? Small proteinacious infectious particles; mutant form of a host protein; classified as slow virusues but they have no virion structrue or genome; resistant to chemicals, heat and ionizing radiation.
Prions
Define: Includes all members of microbial communities at individual body sites.
Microbiome
What is the primary causative agent of gastroenteritis in the US?
Salmonella
What is the primary cause of kidney failure in 1-4 year old in Canada & US?
O157:H7
Define: any substance tha may be specifically bound by an antibody molecule or a B or T cell receptor.
Antigen
How do you know that your antigen is a 'good' antigen?
It elicits an immune response.
What is the difference between a primary response and secondary response to an antigen?
Secondary response is 1) sooner 2) longer 3) bigger (greater in magnitude)
Why do we want to test antigens for their ability to induce an immune response?
Protection via vaccines
What sort of molecules make a good antigens?
Good antigens are big, complex and foreign molecules
What are the five variables that affect the immunogenicity of an antigen?
1. Dose 2. Route 3. Composition 4. Similarity to self 5. Adjuvants
What percent of pathogens are cleared from the body via the innate immune system?
95%
______________ enhance the immune responses by delaying the release of antigen.
Adjuvant
Give an example of one approved adjuvant.
Alum (Aluminum hydroxide in gel form)
Give another term for an antigenic determinant.
epitope
Define: Having multiple antigenic determinants on the surface of an antigen.
Multivalent antigens
Give two forms of multivalent antigens.
Different epitopes and repeated epitopes
Define: Small changes in cell surface antigens ie hemagglutinin and neuraminidase antigens.
Antigenic drift or mutations
Define: Segmented influenza genome among species; or major reassortment of the genome.
Antigenic shift
True/False: All antibodies are immunoglobulins.
TRUE
Antibodies are composed of how many chain molecules?
4
Describe the composition of the 4 antibody chain molecules?
2 Heavy (H) and 2 Light (L) chains covalently linked by S-S bonds
Define: A malignant disease in which one specific B cell clone multiplies repeatedly.
Multiple Myeloma
Describe the differences between the five structures of the immunoglobulin.
location of the hinge, heavy chain.
What are the two kinds of light chains?
kappa and lambda
True/False: Antibodies can contain both kappa or lambda light chains.
False, they can contain either kappa or lambda but not both.
Define: Substances that is able to provoke an adaptive immune response if injected on its own.
Immunogen
What are the four ways in which antibodies work?
1. Neutralization 2. Agglutination 3. Opsonization 4. Complement interactions
Define: Conserved molecular structures on the surface of pathogens
PAMPs Pathogen Associated Molecular Patterns
How many classes of antibodies are there?
IgA, IgG, IgM, IgD, IgE
True/False: Both L chains and H chains have variable & constant regions.
TRUE
Each V region and C subregion of an antibody constitutes a __________.
Domain
Distinguish between hypervariable regions and framework residues.
Hypervariable regions can change dramatically to fit a specific antigen; framework residues form the foundation for the hypervariable regions
List the regions of the antibody that make it a useful reagent for immunological assay.
Highly variable/highly specific light chains, non-antigen binding region is available for chemical coupling to "reporter" molecules.
ELISA, Radio-immunoassay (RIA), FACS , immunofluoresence, western blot, and coombs test are all what type of immunological methods?
Antibody-based methodologies
List two types of clelular assays.
Proliferation assay and cytotoxicity assay
List two nucleic acid-based assays.
Southern blot and microarray ("Gene chip") analyses
Pathogens, pathogen products, or serum antibodies are examples of antigens detected in what antibody-based immunoassay?
ELISA
When target is in low concentration, such as hormones, what is the preferred antibody-based immunoassay?
Radio-immunoassay (similar to ELISA)
Cell surface proteins (markers of activation state, cell type) and internal proteins (e.g. cytokines, cytoplasmic signaling molecules) are examples of antigens which are detected in what antibody-based immunoassay?
FACS analysis
In addition to FACS analysis what other antibody-based immunoassay could be used to detect cell surface proteins and internal cellular proteins?
Immunofluorescence
Cellular proteinsor pathogen proteins, typically in a denatured form, are antigens detected by what antibody-based immunoassay?
Western blot
Cell surface antigens (RBCs) are detected via what type of antibody based immunoassay?
Coombs test
What does ELISA stand for?
Enzyme Linked Immunosorbent Assay (ELISA)
What test: an unknown amount of antigen is affixed to a surface, and then a specific antibody is washed over the surface so that it can bind to the antigen. This antibody is linked to an enzyme, and in the final step a substance is added that the enzyme can convert to some detectable signal. Thus in the case of fluorescence test name, when light of the appropriate wavelength is shone upon the sample, any antigen/antibody complexes will fluoresce so that the amount of antigen in the sample can be inferred through the magnitude of the fluorescence
ELISA
What is the criteria for protective immunity to a particular antigen?
titer >= positive control
In RIA, the amount of radioactivity is _________ proportional to the concentration of hormone in the positive sample when compared with a negative sample.
Inversely
What does FACS stand for?
Fluorescence activated cell sorting
List the three optical properties of particles (cells).
Cell size (scatters light), Cellular granularity (scatters light), and fluorescence (fluorochrome-labeled antibody detection)
What type of immunoassay is being described here? It provides a method for sorting a heterogeneous mixture of biological cells into two or more containers, one cell at a time, based upon the specific light scattering and fluorescence characteristics of each cell. It is a useful scientific instrument, as it provides fast, objective and quantitative recording of fluorescent signals from individual cells as well as physical separation of cells of particular interest.
FACS analysis
What type of immunoassay separates proteins via electrophoresis then detects specific proteins via antibody-enzyme color?
Western blot
T/F: Western Blot requires the separated proteins be transferred from a polyacrylamide gel to a different membrane for further evaulation?
True, polyacrylamide gel is used for electrophoresis, the nitrocellulose gel is used for diagnostic testing.
What test: Used for detection of anti-RBC antibodies bound to RBCs in an individual patient.
Coombs test.
What est would you order for a patient which you suspect has an autoimmune hemolytic anemia?
A direct coombs test because there will be RBC/antibody complexes which cause RBC destruction and the resulting anemia
Differentiate between a direct Coombs test and an indirect Coombs test.
A direct Coombs test detects antibodies already attached to a person's own blood while an indirect coombs test determines whether the serum of another person while react with the patient's RBC
What type of Coombs test? a blood sample is taken and the RBCs are washed (removing the patient's own plasma) and then incubated with antihuman globulin (also known as "Coombs reagent"). If this produces agglutination of RBCs, the ______ Coombs test is positive, a visual indication that antibodies (and/or complement proteins) are bound to the surface of RBCs
Direct Coombs test
Define: Antihuman globulin used in the direct Coombs test.
Coombs reagent (such as Rabbit anti-human immunoglobulin)
List three ways antibodies for clinical assays are obtained.
Patient sera (blood draw), polyclonal antibodies (animal immunization), monoclonal antibodies (hybridomas)
Blood draw is associated with what source of antibodies?
Patient serum
Polyclonal antibodies are produced from what source?
Immunized animals
Monoclonal antibodies are produced from what source?
Hybridomas (immunization of rodents, followed by fusion of reactive spleen cells with tumore cells.
What source of antibody should be used? Used when the patien response to an antigen needs to be assessed.
Patient sera (blood draw)
What source of antibody should be used? Typically used when an antigen needs to be detected with maximal signal (e.g. anti-human antibodies for ELISA detection)
Polyclonal antibodies (rodent immunization)
What source of antibody is described? Typically used when antigen needs to be detected with exquisite specificity.
Monoclonal antibodies (rodent immunization followed by hybridoma)
List an advantage and a disadvantage of using monoclonal antibodies.
Advantage: Great purification value Disadvantage(s): Highly specific, laborious to produce
List an advantage and a disadvantage of using polyclonal antibodies.
Advantage: Cheap to produce Disadvantage: Difficult to purify
Give a specific example where monoclonal antibodies are used in treatment.
anti-TNF-alpha mAbs are used as drugs to treat rheumatoid arthritis
Why is molecular biology required to produce mAbs for humans?
It is very difficult to generate human antibodies
What type of immunoassay? Used to measure the ability of B cells or T cells to proliferate in response to mitogenic stimuli.
Proliferation assay
Where are polyclonal antibodies isolated from?
Serum (murine or other lab animal)
What type of immunoassay is described? B or T cells are placed in tissue culture with radiolabeled nucleic acids and a mitogenic stimulation. After several hours of growth, excess label is washed out, and cells are harvested. Measurement of incorporation of radiolabel allows the proliferative response to be quantified.
Proliferation assay
What test would be ordered? Various tests have failed to indicate a pathogen infection (AIDS has been ruled out); FACS shos the patient has normal numbers of T cells.
Proliferation assay which reveals that in response to various T cell mitogenic stimuli, Patient #1 shows little or no T cell proliferation.
CD3, CD28, IL2 are all examples of what type of signal for B or T cells?
Mitogenic signals used in the proliferation assay.
In a cytotoxicity assay (chromium release assay); what is being measured?
The efficient of the effector cells
What type of immunoassay? Target cells are loaded with radioactive chromium, effector cells are added into the solution; incubation; media removed and percent of radioactive chromium in the media is calculated to determine % specific lysis.
Cytotoxicity assay: Chromium release assay
What type of test would you order when you suspected T cell numbers are good and proliferating but they are failing to activate?
Cytotoxicity assay: Chromium release assay
What test is used in clinical immunology specifically for the detection of specific chromosomal rearragnements, partciularly in lymphocyte tumors.
Southern blot
Which immunoassay is being described? 1. Separation of endonuclease-digested DNA fragments 2. Transfer of DNA to a nylon membrane 3. Hybridaization to a specific radiolabeled DNA probe. 4. Exposure to X-ray film to visualize specific DNA fragments.
Southern blot
When you suspect DNA or want to characterize a tumor better what method of immunoassay would you perform?
Southern blot
What immunoassay provides simultaneous analysis of expression of thousands of genes concurrently?
Microarray ("Gene chip") analyses
What test is being described? Glass slide is prepared with DNA sequences from individual genes; two samples (normal and patient) are put through reverse transcriptase to form mRNA; Patient and control are fluorscently dyed differently; Patient and Control differently dyed mRNA is competitively hybridized with the DNA prepared glass slide; data is collected on fluorescent status of each spot.
What assay should be used? Desire for unique genetic information, determination of carrier status for cystic fibrosis; snapshot of cancer's expression of different genes.
Microarray ("Gene chip") analyses
List the four major groups of cellular adhesion molecules (CAMs).
1. Immunoglobulin Superfamily 2. Integrin family 3. Selectin Family 4. Vascular addressins
Which family of CAMs? ICAM-1, ICAM-2, CD2, CD4, CD8. Structures based on immunoglobulin fold.
Immunoglobulin superfamily
Which family of CAMs? LFA-1; heterodimers of alpha and beta chains; subfamilies named after shared beta chain.
Integrin family
Which family of CAMs? Extracellular portion of molecule terminates in a lectin domain; binds to carbohydrate ligands, facilitating interactions between leukocytes and endothelial cells; L-selectin
Selectin family
Which family of CAMs? Molecules bearing the carbohydrate ligands that are recognized by L-Selectin; such as CD34, GlyCAM-1
Vascular addressins
What is it? The antigen receptor on b cells which is a membrane bound immunoglobulin molecule.
B cell receptor
What is it? The highly variable antigen receptor of T lymphocytes composed of a variable alpha chain and a variable beta chain; known as the alph:Beta t-cell receptor.
T cell receptor
What molecule? Complex of signaling proteins that associates with T-cell receptors. Consists of CD3γ, δ, ε, and ζ chains
CD3
What molecule? Adhesion molecule on T cells that binds to the LFA-3 adhesion molecule on antigen-presenting cells.
CD2
What molecule? Cell-surface glycoprotein that distinguishes a subset of t cells that recognize antigens present by MHC class II molecules.
CD4
What binds to MHC class II molecules on the antigen-presenting cell and acts a s a co-receptor to augment the T cell's response to antigen?
CD4
What molecule? Cell surface glycoprotein that distginsuiches a subset of t cells that recognize antigens presented by MHC class I molecules.
CD8
What binds to MHC class I molecules on the antigen-presenting cell and acts as a co-receptor to augment the T cell's response to antigen?
CD8
What molecule? The low-affinity receptor on T cells that interacts with B7 co-stimulatory molecules to promote T-cell activation.
CD28
What molecule? Vascular addressin that is expressed on high endothelial venules in lymph nodes and is involved in the extravasation of white blood cells?
CD34
What molecule? Cell -surface glycoprotein on B cells whose interaction with CD40 ligand on helper T cells triggers B-cell proliferation.
CD40
What molecule? T cell Ligand protein which interacts with CD40 cell-surface glycoprotein on B cells whose interaction triggers B cell proliferation.
CD40L
What molecule? Vascular addressin present on the high enothelial venules of secondary lymphoid tissue. It is an important ligand for the L-selectin adhesion molecule on naïve lymphocytes and directs these cells to leave the blood and enter the lymphoid tissues.
GlyCAM-1
What is an important ligand for the L-selectin adehsion molecule on naïve lymphocytes and directs these cells to leave the blood and enter the lymphoid tissue?
GlyCAM-1
What molecule? Co stimulatory molecules present on the surface of professional antigen-presenting cells such as dendritic cells; examples B7.1 and B7.2 proteins.
B7 molecules
What molecule? High-affinity inhibitory receptor on T cells that interacts with B7 co-stimulatory molecules.
CTLA4
What two molecules (a high and low affinity) interact with B7 co-stimulatory molecules on professional antigen presenting cells.
CTLA4 (high affinity) and CD28 (low affinity)
Give names for three different types of intercellular adhesion molecules.
ICAM-1, ICAM-2, ICAM-3
What molecule? Cytokine produced by activated T cells that is essential for the proliferation of activated T cells and the development of and adaptive immune response.
Interleukin-2
What molecule? Cytokine receptor for Interleukin-2 on T cells
IL-2R
What molecule? One of the leukocyte integrins that mediate the adhesion of lymphocytes, expecially T cells, to endothelial cells and antigen-presenting cells.
LFA-1 (Leukocyte function-associated antigen-1)
What molecule? An adhesion molecule of the selectin family found on lymphocytes. It binds to CD34 and GlyCAM-1 on High Endothelial venules to initiate the migration of naïve lymphocytes into secondary lymphoid tissue.
L-selectin
What do CD28, CTLA-4 and CD40 have in common?
All interact with leukocytes to regulate T cells
What is the difference between CD28 and CTLA-4?
CD28 sends a stimulatory signal while CTLA-4 sends an inhibitory signal to T cells
What is in common between CD28 and CD40?
They are both stimulatory (CD28 stimulates T cells and CD40 stimulates APCs)
Define: a lack of reaction by the body's defense mechanisms to foreign substances, and consists of a direct induction of peripheral lymphocyte tolerance.
Anergic
Helper T lymphocyte interacts with which class of MHC-expressing APC?
MHC II class expressing APC interacts with CD4+ TH
MHC I class expressing APC interacts with which T cell subtype?
CD8+ Cytotoxic T cell
List the six molecules bound to a CD4 T cell.
LFA-1, CD4, CD3, TCR, CD2 and CD28
List the six molecules bound to a CD8 T cell.
LFA-1, CD8, CD3, TCR, CD2 and CD28
What is the main difference in signaling molecules between a helper T cell and a cytotoxic t cell?
CD4 versus CD8
What molecule interacts with LFA-1?
ICAM-1
What molecules interacts with CD4 (helper), CD3, ζ chain, and TCR?
Antigen and MHC class II
What molecules interacts with CD8 (cytotoxic), TCR, ζ chain, and CD3?
Antigen and MHC class I
List the four molecules which compose the interaction with MHC class I or class II.
CD4 helper (MHC II) or CD8 cytotoxic (MHC I), CD3, TCR and ζ chain.
What molecule interacts with C2 on T cells?
LFA-3
What molecule interacts with CD28 on T cells?
B7.1 or B7.2 molecules
What molecule serves for specific recognition of antigen?
TCR
What 5/6 molecules serves for signal transduction of the specific recognition of the antigen?
CD4/CD8, ζ chains, CTLA-4, CD2 and CD28
What three molecules serve as adhesion points?
L-selectin, LFA-1, CD2
Define: Describes any signal that is required for the activation of a naïve lymphocyte in addition ot eh signal delivered via the antigen receptor.
Costimulatory
What are the two T cell "costimulatory" molecules?
CD28 (positive effect) and CTLA-4 (negative effect)
What functions as the the signal transducing subunit of the TCR?
CD3
When a cell signals to itself and increase the affinity of LFA-1 for ICAM-1 what process has occurred?
inside out signaling
Helper T lymphocyte interacts with which class of MHC-expressing APC?
Antigen recognition/TCR engagement
What functions as an efficient means of information transfer from the APC to the T cell?
Immunological synapse and SMACs
What is the costimulatory molecule for B cells?
CD40
What is the basic function of helper T cells?
Activate other components of the adaptive response (such as B cells and macrophages)
Describe the organziation of the immunological synapse.
Composed of three concentric circles (C-SMAC, P-SMAC, and D-SMAC) each containing a peculiar mix of molecules.
Define: Proteins made by cells that affect the behavior of other cells.
Cytokine
Define: Describes a cytokine or other secreted molecule that acts on the same type of cell as the one that secreted it.
autocrine
What three cell signals are associated with c-SMAC?
TCR, CD4, CD28
What two cell signals are associated with p-SMAC?
LFA-1:ICAM-1
Define: Cytokine acts systemically in distant cells.
Endocrine
Define: Cytokine acts on neighbroing cells.
Paracrine
IL-2 secretion during T cell activation is an example of what type of cytokine?
autocrine
Chemokine recruitment of leukocytes to sites of inflammation is an example of what type of cytokine?
paracrine
IL-1, IL-6, and TNF-α are examples of what type of cytokine?
endocrine
True/False: Interleukin 2 is synthesized and secreted by the activated T cell itself.
TRUE
What is the signficance of the 3 chain structure of the IL-2 receptor?
The 3 chain has a high affinity and is expressed by activated T cells; Naïve T cell expresses a two chain IL-2.
What is required for the production of IL-2?
TCR signal and coreceptor copmlex and costimulatory signal through CD28
What is one of the functions of the co-stimulatory signal of T cell's activation?
Stabilization of cytokine mRNA to increase IL2 cytokine production 20-30 fold
What is the end result of IL-2 binding to its high affinity receptor?
Triggers the t cell to divide two to three times a day.
Describe the effects of rapamycin suppressing the immune response.
Rapamycin inhibits signaling from the IL-2 receptor disrupting T celll increased proliferation (which suppresses all immune responses that require activated T cells)
Define: Chemoattractant cytokines
chemokines
Describe the general features of cellular response to chemokines?
Directs the flow of leukocyte traffic; attraction via chemokine gradients
What viruses use CD4, ICAM-1 and CD155 as receptors to enter the host cell?
CD4=HIV, ICAM-1=Rhinovirus, CD155=Poliovirus
What are the four stages of neutrophil extravasation?
1. Rolling adhesion 2. Tight binding 3. Diapedesis 4. Migration
P-selectin, E-selectin on the endothelial wall and Carbohydrate side chain known as sialyl Lewisx are all cell interaction molecules associated with what part of neutrophil extravasation?
Rolling adhesion
Integrins LFA-1 and CR3 on the neutrophil and adhesion molecules on endothelium such as ICAM-1 (in the presence of CXCL8, chemokine) are important in what part of neutrophil extravasation?
Tight binding
LFA-1 (integrin), CR3 (integrins), CD31 on neutrophils and CD31 on the endothelium are present in which part of neutrophil extravasation?
Diapesdesis
What are the four effects of antibodies?
Opsonize, neutralize, agluttinization and complementation
CXCL8 is the cytokine (or chemokine) which mediates in what part of neutrophil extravasation?
homing
What is the molecular bases for leukocyte adhesion deficiency (LAD)?
A defect in the β2 integrin gene mutation
What are the two important functions of Innate immunity?
1. Initial response to microbes 2. Stimulates adaptive immune responses to be optimally effective against different types of microbes
Define: Microbrial substances that stiulate innate immunity which are generally conserved and universal for microbes.
Pathogen-associated molecular patterns (PAMPs)
Define: Host receptors that bind to PAMPs.
Pattern recognition receptors (PRRs)
T/F: PRRs are only expressed on the cell-surface
False, pattern recognition receptors may be secreted, cell surface expressed or intracellular.
What does activation of PRRs lead to?
Pattern recognitiion receptor activation results in secretion of proinflammatory cytokines and enhanced microbial killing.
Toll-like receptors, n-formyl-mehtionyl receptor, mannose receptors and scavenger receptors are all examples of?
Pattern recognition receptors (PRRs)
List five cellular expression product types of Toll-like Receptors (TLRs).
1. Inflammatory cytokines (TNF, IL-1, IL-12) 2. Chemokines (IL-8,MCP-1, RANTES) 3. Endothelial adhesion molecules (E-selectin) 4. Costimulatory molecules (CD80, CD86) 5. Antiviral cytokines.
TNF, IL-1, IL-12 are all examples of what?
Inflammatory cytokines
IL-8, MCP-1, and RANTES are all examples of what?
Chemokines
Does this statement describe the adaptive immunity or the innate immunity? Specificity for structures shared by classes of microbes (PAMPs).
Innate (PAMPs = Pathogen Associated molecular patterns)
Does this statement describe the adapative immunity or the innate immunity? Receptors are encoded by genes produced by somatic recombination of gene segments: greater diversity.
Adaptive immunity
Does this statement describe the adaptive immunity or the innate immunity? The distribution of receptors is non-clonal: identical receptors on all cells of the same lineage.
Innate immunity
Does this statement describe the adaptive immunity or the innate immunity? Specificity for structrual detail of microbial molecules (antigens); may recognize non-microbial antigens.
Adaptive immunity
Does this statement describe the adaptive immunity or the innate immunity? Self/Non-self; Host cells are not recognized or they may express molecules that prevent this type of immunity.
Innate immunity
Does this statement describe the adaptive immunity or the innate immunity? Receptors are encoded in germinlin; limited diversity (PRRs).
Innate immunity
Does this statement describe the adaptive immunity or the innate immunity? Self/Non-self; Based on selection against self-reactive lymphocytes; maybe imperfect.
Adaptive immunity
Which immunity has a limited repertoire of receptors?
Innate
What is the majore cellular response of innate immunity?
Inflammation
Define: Changes in the host in response to an antigen that allows movement of serum proteins & leukocytes to move from the circulation into the tissues.
Inflammation
List the four characteristics (in Latin) of inflammation.
Rubor, Calor, Tumor, and Dolor
T/F: The skin produces chemicals which act as barriers to pathogens.
TRUE
What is an extension of the skina nd lines the digestive track from mouth to anus; Is composed of epithelial cells and forms a physical barrier?
Mucosa
How is the epithelial cells in the small & largintestines organized?
Into villi
Give an example of follicle-associated epithelium.
Peyer's patches
What cell uptakes antigens from the gut lumen and releases them to an APC?
M cells
FITB: The early stages of inflammation are characterized by a release in __________ inflammatory mediators in secretory granules, such as histamine, serotonin, platelet activating factor, and lysosomal enzymes from local cells.
preformed
List four preformed inflammatory mediators released from secretory granules in local cells during early stages of inflammation.
Histamine, serotonin, platelet activating factor, and lysosomal enzymes.
Besides inflammatory mediators what other two class of compounds are released as part of the early inflammatory response?
Defensins (antimicrobial, chemokines) and Complement (Vasodilation, edema, opsonization)
What are the two types of defensins?
Alpha (Neutrophil and Paneth) and Beta (epithelial)
What type of defensin? Secreted by Neutrophils, and Paneth cells; naïve T cell chemoattractant; attracts immature dendritic cells and activates complement system.
Alpha defensins
What type of defensin? Secreted by epithelial cells; upregulated by LPS or TNF-alpha; Memory cell chemoattractant; attracts immature dendritic cells.
Beta defensins
Define: A set of plasma proteins that act together to help eliminate extracellular forms of pathogens.
The Complement cascade
What are the two major functions of the complement cascade?
Opsonization and chemotaxis
What is the ultimate convergance of the three pathways (Classical, MB-lectin, and alternative)?
Synthesis of C3 convertase
What are the four results of C3 convertase synthesis? I.E. What does C3 Convertase do?
1. Degrades into C3 into C3a, C5a and C3b effector molecules 2. Allows formation of Membrane Attack complexes 3. C3a & C5a (anaphylatoxins) increase vascular permeability 4. Allows binding of C3b to C receptors on phagocytes
C5b, C6-C9 are all involved in what terminal reactions in the complement cascade?
Membrane-attack complex, lysis of certain pathogens and cells
C3b accomplishes what terminal reactions in the complement cascade?
Opsonization of pathogens (via binding to complement receptors on phagocytes)
C3a and C5a accomplishes what terminal actions in the complement cascade?
Peptide inflammatory mediators; phagocyte recruitment
C1INH, C4BP, Factors H & I, DAF, MCP, CS59, and Factor P play what role in complement cascade?
Determine the extent and site of C3b deposition
List the four major cell types of the innate immune response.
Neutrophs, monocytes (macrophages), mast cells, and natural killer cells
In addition to neutrophils, monocytes (macrophages), mast cells and natural killer cells what other two additional cell types are part of the innate immune response?
T cells (intraepithelial lymphocytes) and B cells (B-1 B cells)
FITB: Mast cells, like ___________ are also sentinel cells.
Macrophage
What are the first lymphocytes of the host to encounter pathogens after oral infection?
Intraepithelial lymphocytes (IELS)
True/False as pathogens became more complex so did the immune system.
TRUE
What type of immunity is described? Slow response (days to weeks), variable, numerous highly selective specificities, improve during response.
Adaptive immunity
List the four major components of the adaptive immune response.
1. Self vs non self recognition 2. Antigen-recognition molecules 3. clonal selection 4. memory
What type of immunity is termed the first line defense?
innate immunity
What type of immunity is described? Rapid response (hours); invariant; limited number of specificities; constant during response.
Innate immunity
Whih type of immunity is considered constitutive?
Innate immunity
Which type of immunity is considered inducible?
Adaptive immunity
Induction and control (in the form of tolerance/homeostasis) refer to what immunity?
Adaptive immunity
What are the three components of induction (in the adaptive immunity)?
1. Inducibility 2. specificity 3. clonality
True/False all cells in the immune system are white blood cells (leukocytes) and derive from the hematopoietic stem cell pool.
TRUE
Cell types associated with innate immunity are mostly from the _____________ lineage.
Myeloid
Cell types associated with adaptive immunity are mostly from the ___________ lineage.
Lymphoid
What are the two arms of the adaptive immunity?
humoral and cell-mediated
Which type of cell mediates the humoral adaptive response?
B cells
Which type of cell mediates the cell-mediated adaptive response?
T cells
Which arm of the adaptive immune response deal with extracellular pathogens?
Humoral adaptive response
Which arm of the adaptive immune response deals with intracellular pathogens?
cell-mediated
Differentiate between primary and secondary lymphoid organs.
Immune cell primordial development occurs in the primary lymphoid organs (thymus and bone marrow) whereas immune cell education occurs in the secondary lymphoid organs.
List four secondary lymphoid organs.
Spleen, tonsils, lymph nodes, and peyer's patches
How are the secondary lymphoid organs further divided?
Mucosal and systemic
Describe the function of mucosal secondary lymphoid organs.
Protect against pathogens attacking the mucosa
List the four 'eyes' of pathogens (multiple routes of entry).
Ingestion, Inhalation, injection, insemination
Waldeyer's ring (lymph nodes, tonsils and adenoids), bronchus-associated lymphoid tissue, lamina propria, peyer's patch and urogenital lymphoid tissue are all examples of which division of the secondary lymphoid tissue?
Mucosal
Lymph nodes, spleen, amd mesenteric lymph nodes are all examples of what division of the secondary lymph nodes?
Systemic
The _______________ lymphoid organs serve as filters across the blood, lymph & intestines.
Secondary lymphoid organs
Granulocytes are from what lineage?
Myeloid
True/False: T cells form germinal centers inside the lymph node.
False! B cells form the germinal centers in the lymphoid follicle.
Are the T cell areas deeper (toward the medulla) of the lymph node than the lymphoid follicle?
Yes the are under the lymphoid follicle and the germinal center.
List the five classes of infectious agents.
1. Viruses 2. Fungi 3. Bacteria 4. Parasites 5. Prions
What infectious agent? Smallest infectious particle; DNA or RNA based (only one class has both); components enclosed in a protein coat with or without lipid membrane; true parasites; require host cells for replication.
Virus
What infectious agent? Univellular prokaryotes; 1-20 microns; different shapes; divide by binary fission (assexual); Gram +/-.
Bacteria
What infectious agent? Eukaryotic organisms; two forms asexual and sexual; dimorphic (asexual/sexual)
Fungi
What does dimorphic mean?
Can reproduce by either sexual or assexual means
What infectious agent? Complex eukaryotes; some unicellular, others multicellular; can range in size from tiny protozoa to 10 meter tapeworms.
Parasites
What infectious agent? Small proteinacious infectious particles; mutant form of a host protein; classified as slow virusues but they have no virion structrue or genome; resistant to chemicals, heat and ionizing radiation.
Prions
Define: Includes all members of microbial communities at individual body sites.
Microbiome
What is the primary causative agent of gastroenteritis in the US?
Salmonella
What is the primary cause of kidney failure in 1-4 year old in Canada & US?
O157:H7
Define: any substance tha may be specifically bound by an antibody molecule or a B or T cell receptor.
Antigen
How do you know that your antigen is a 'good' antigen?
It elicits an immune response.
What is the difference between a primary response and secondary response to an antigen?
Secondary response is 1) sooner 2) longer 3) bigger (greater in magnitude)
Why do we want to test antigens for their ability to induce an immune response?
Protection via vaccines
What sort of molecules make a good antigens?
Good antigens are big, complex and foreign molecules
What are the five variables that affect the immunogenicity of an antigen?
1. Dose 2. Route 3. Composition 4. Similarity to self 5. Adjuvants
What percent of pathogens are cleared from the body via the innate immune system?
95%
______________ enhance the immune responses by delaying the release of antigen.
Adjuvant
Give an example of one approved adjuvant.
Alum (Aluminum hydroxide in gel form)
Give another term for an antigenic determinant.
epitope
Define: Having multiple antigenic determinants on the surface of an antigen.
Multivalent antigens
Give two forms of multivalent antigens.
Different epitopes and repeated epitopes
Define: Small changes in cell surface antigens ie hemagglutinin and neuraminidase antigens.
Antigenic drift or mutations
Define: Segmented influenza genome among species; or major reassortment of the genome.
Antigenic shift
True/False: All antibodies are immunoglobulins.
TRUE
Antibodies are composed of how many chain molecules?
4
Describe the composition of the 4 antibody chain molecules?
2 Heavy (H) and 2 Light (L) chains covalently linked by S-S bonds
Define: A malignant disease in which one specific B cell clone multiplies repeatedly.
Multiple Myeloma
Describe the differences between the five structures of the immunoglobulin.
location of the hinge, heavy chain.
What are the two kinds of light chains?
kappa and lambda
True/False: Antibodies can contain both kappa or lambda light chains.
False, they can contain either kappa or lambda but not both.
Define: Substances that is able to provoke an adaptive immune response if injected on its own.
Immunogen
What are the four ways in which antibodies work?
1. Neutralization 2. Agglutination 3. Opsonization 4. Complement interactions
Define: Conserved molecular structures on the surface of pathogens
PAMPs Pathogen Associated Molecular Patterns
How many classes of antibodies are there?
IgA, IgG, IgM, IgD, IgE
True/False: Both L chains and H chains have variable & constant regions.
TRUE
Each V region and C subregion of an antibody constitutes a __________.
Domain
Distinguish between hypervariable regions and framework residues.
Hypervariable regions can change dramatically to fit a specific antigen; framework residues form the foundation for the hypervariable regions
List the regions of the antibody that make it a useful reagent for immunological assay.
Highly variable/highly specific light chains, non-antigen binding region is available for chemical coupling to "reporter" molecules.
ELISA, Radio-immunoassay (RIA), FACS , immunofluoresence, western blot, and coombs test are all what type of immunological methods?
Antibody-based methodologies
List two types of clelular assays.
Proliferation assay and cytotoxicity assay
List two nucleic acid-based assays.
Southern blot and microarray ("Gene chip") analyses
Pathogens, pathogen products, or serum antibodies are examples of antigens detected in what antibody-based immunoassay?
ELISA
When target is in low concentration, such as hormones, what is the preferred antibody-based immunoassay?
Radio-immunoassay (similar to ELISA)
Cell surface proteins (markers of activation state, cell type) and internal proteins (e.g. cytokines, cytoplasmic signaling molecules) are examples of antigens which are detected in what antibody-based immunoassay?
FACS analysis
In addition to FACS analysis what other antibody-based immunoassay could be used to detect cell surface proteins and internal cellular proteins?
Immunofluorescence
Cellular proteinsor pathogen proteins, typically in a denatured form, are antigens detected by what antibody-based immunoassay?
Western blot
Cell surface antigens (RBCs) are detected via what type of antibody based immunoassay?
Coombs test
What does ELISA stand for?
Enzyme Linked Immunosorbent Assay (ELISA)
What test: an unknown amount of antigen is affixed to a surface, and then a specific antibody is washed over the surface so that it can bind to the antigen. This antibody is linked to an enzyme, and in the final step a substance is added that the enzyme can convert to some detectable signal. Thus in the case of fluorescence test name, when light of the appropriate wavelength is shone upon the sample, any antigen/antibody complexes will fluoresce so that the amount of antigen in the sample can be inferred through the magnitude of the fluorescence
ELISA
What is the criteria for protective immunity to a particular antigen?
titer >= positive control
In RIA, the amount of radioactivity is _________ proportional to the concentration of hormone in the positive sample when compared with a negative sample.
Inversely
What does FACS stand for?
Fluorescence activated cell sorting
List the three optical properties of particles (cells).
Cell size (scatters light), Cellular granularity (scatters light), and fluorescence (fluorochrome-labeled antibody detection)
What type of immunoassay is being described here? It provides a method for sorting a heterogeneous mixture of biological cells into two or more containers, one cell at a time, based upon the specific light scattering and fluorescence characteristics of each cell. It is a useful scientific instrument, as it provides fast, objective and quantitative recording of fluorescent signals from individual cells as well as physical separation of cells of particular interest.
FACS analysis
What type of immunoassay separates proteins via electrophoresis then detects specific proteins via antibody-enzyme color?
Western blot
T/F: Western Blot requires the separated proteins be transferred from a polyacrylamide gel to a different membrane for further evaulation?
True, polyacrylamide gel is used for electrophoresis, the nitrocellulose gel is used for diagnostic testing.
What test: Used for detection of anti-RBC antibodies bound to RBCs in an individual patient.
Coombs test.
What est would you order for a patient which you suspect has an autoimmune hemolytic anemia?
A direct coombs test because there will be RBC/antibody complexes which cause RBC destruction and the resulting anemia
Differentiate between a direct Coombs test and an indirect Coombs test.
A direct Coombs test detects antibodies already attached to a person's own blood while an indirect coombs test determines whether the serum of another person while react with the patient's RBC
What type of Coombs test? a blood sample is taken and the RBCs are washed (removing the patient's own plasma) and then incubated with antihuman globulin (also known as "Coombs reagent"). If this produces agglutination of RBCs, the ______ Coombs test is positive, a visual indication that antibodies (and/or complement proteins) are bound to the surface of RBCs
Direct Coombs test
Define: Antihuman globulin used in the direct Coombs test.
Coombs reagent (such as Rabbit anti-human immunoglobulin)
List three ways antibodies for clinical assays are obtained.
Patient sera (blood draw), polyclonal antibodies (animal immunization), monoclonal antibodies (hybridomas)
Blood draw is associated with what source of antibodies?
Patient serum
Polyclonal antibodies are produced from what source?
Immunized animals
Monoclonal antibodies are produced from what source?
Hybridomas (immunization of rodents, followed by fusion of reactive spleen cells with tumore cells.
What source of antibody should be used? Used when the patien response to an antigen needs to be assessed.
Patient sera (blood draw)
What source of antibody should be used? Typically used when an antigen needs to be detected with maximal signal (e.g. anti-human antibodies for ELISA detection)
Polyclonal antibodies (rodent immunization)
What source of antibody is described? Typically used when antigen needs to be detected with exquisite specificity.
Monoclonal antibodies (rodent immunization followed by hybridoma)
List an advantage and a disadvantage of using monoclonal antibodies.
Advantage: Great purification value Disadvantage(s): Highly specific, laborious to produce
List an advantage and a disadvantage of using polyclonal antibodies.
Advantage: Cheap to produce Disadvantage: Difficult to purify
Give a specific example where monoclonal antibodies are used in treatment.
anti-TNF-alpha mAbs are used as drugs to treat rheumatoid arthritis
Why is molecular biology required to produce mAbs for humans?
It is very difficult to generate human antibodies
What type of immunoassay? Used to measure the ability of B cells or T cells to proliferate in response to mitogenic stimuli.
Proliferation assay
Where are polyclonal antibodies isolated from?
Serum (murine or other lab animal)
What type of immunoassay is described? B or T cells are placed in tissue culture with radiolabeled nucleic acids and a mitogenic stimulation. After several hours of growth, excess label is washed out, and cells are harvested. Measurement of incorporation of radiolabel allows the proliferative response to be quantified.
Proliferation assay
What test would be ordered? Various tests have failed to indicate a pathogen infection (AIDS has been ruled out); FACS shos the patient has normal numbers of T cells.
Proliferation assay which reveals that in response to various T cell mitogenic stimuli, Patient #1 shows little or no T cell proliferation.
CD3, CD28, IL2 are all examples of what type of signal for B or T cells?
Mitogenic signals used in the proliferation assay.
In a cytotoxicity assay (chromium release assay); what is being measured?
The efficient of the effector cells
What type of immunoassay? Target cells are loaded with radioactive chromium, effector cells are added into the solution; incubation; media removed and percent of radioactive chromium in the media is calculated to determine % specific lysis.
Cytotoxicity assay: Chromium release assay
What type of test would you order when you suspected T cell numbers are good and proliferating but they are failing to activate?
Cytotoxicity assay: Chromium release assay
What test is used in clinical immunology specifically for the detection of specific chromosomal rearragnements, partciularly in lymphocyte tumors.
Southern blot
Which immunoassay is being described? 1. Separation of endonuclease-digested DNA fragments 2. Transfer of DNA to a nylon membrane 3. Hybridaization to a specific radiolabeled DNA probe. 4. Exposure to X-ray film to visualize specific DNA fragments.
Southern blot
When you suspect DNA or want to characterize a tumor better what method of immunoassay would you perform?
Southern blot
What immunoassay provides simultaneous analysis of expression of thousands of genes concurrently?
Microarray ("Gene chip") analyses
What test is being described? Glass slide is prepared with DNA sequences from individual genes; two samples (normal and patient) are put through reverse transcriptase to form mRNA; Patient and control are fluorscently dyed differently; Patient and Control differently dyed mRNA is competitively hybridized with the DNA prepared glass slide; data is collected on fluorescent status of each spot.
What assay should be used? Desire for unique genetic information, determination of carrier status for cystic fibrosis; snapshot of cancer's expression of different genes.
Microarray ("Gene chip") analyses
List the four major groups of cellular adhesion molecules (CAMs).
1. Immunoglobulin Superfamily 2. Integrin family 3. Selectin Family 4. Vascular addressins
Which family of CAMs? ICAM-1, ICAM-2, CD2, CD4, CD8. Structures based on immunoglobulin fold.
Immunoglobulin superfamily
Which family of CAMs? LFA-1; heterodimers of alpha and beta chains; subfamilies named after shared beta chain.
Integrin family
Which family of CAMs? Extracellular portion of molecule terminates in a lectin domain; binds to carbohydrate ligands, facilitating interactions between leukocytes and endothelial cells; L-selectin
Selectin family
Which family of CAMs? Molecules bearing the carbohydrate ligands that are recognized by L-Selectin; such as CD34, GlyCAM-1
Vascular addressins
What is it? The antigen receptor on b cells which is a membrane bound immunoglobulin molecule.
B cell receptor
What is it? The highly variable antigen receptor of T lymphocytes composed of a variable alpha chain and a variable beta chain; known as the alph:Beta t-cell receptor.
T cell receptor
What molecule? Complex of signaling proteins that associates with T-cell receptors. Consists of CD3γ, δ, ε, and ζ chains
CD3
What molecule? Adhesion molecule on T cells that binds to the LFA-3 adhesion molecule on antigen-presenting cells.
CD2
What molecule? Cell-surface glycoprotein that distinguishes a subset of t cells that recognize antigens present by MHC class II molecules.
CD4
What binds to MHC class II molecules on the antigen-presenting cell and acts a s a co-receptor to augment the T cell's response to antigen?
CD4
What molecule? Cell surface glycoprotein that distginsuiches a subset of t cells that recognize antigens presented by MHC class I molecules.
CD8
What binds to MHC class I molecules on the antigen-presenting cell and acts as a co-receptor to augment the T cell's response to antigen?
CD8
What molecule? The low-affinity receptor on T cells that interacts with B7 co-stimulatory molecules to promote T-cell activation.
CD28
What molecule? Vascular addressin that is expressed on high endothelial venules in lymph nodes and is involved in the extravasation of white blood cells?
CD34
What molecule? Cell -surface glycoprotein on B cells whose interaction with CD40 ligand on helper T cells triggers B-cell proliferation.
CD40
What molecule? T cell Ligand protein which interacts with CD40 cell-surface glycoprotein on B cells whose interaction triggers B cell proliferation.
CD40L
What molecule? Vascular addressin present on the high enothelial venules of secondary lymphoid tissue. It is an important ligand for the L-selectin adhesion molecule on naïve lymphocytes and directs these cells to leave the blood and enter the lymphoid tissues.
GlyCAM-1
What is an important ligand for the L-selectin adehsion molecule on naïve lymphocytes and directs these cells to leave the blood and enter the lymphoid tissue?
GlyCAM-1
What molecule? Co stimulatory molecules present on the surface of professional antigen-presenting cells such as dendritic cells; examples B7.1 and B7.2 proteins.
B7 molecules
What molecule? High-affinity inhibitory receptor on T cells that interacts with B7 co-stimulatory molecules.
CTLA4
What two molecules (a high and low affinity) interact with B7 co-stimulatory molecules on professional antigen presenting cells.
CTLA4 (high affinity) and CD28 (low affinity)
Give names for three different types of intercellular adhesion molecules.
ICAM-1, ICAM-2, ICAM-3
What molecule? Cytokine produced by activated T cells that is essential for the proliferation of activated T cells and the development of and adaptive immune response.
Interleukin-2
What molecule? Cytokine receptor for Interleukin-2 on T cells
IL-2R
What molecule? One of the leukocyte integrins that mediate the adhesion of lymphocytes, expecially T cells, to endothelial cells and antigen-presenting cells.
LFA-1 (Leukocyte function-associated antigen-1)
What molecule? An adhesion molecule of the selectin family found on lymphocytes. It binds to CD34 and GlyCAM-1 on High Endothelial venules to initiate the migration of naïve lymphocytes into secondary lymphoid tissue.
L-selectin
What do CD28, CTLA-4 and CD40 have in common?
All interact with leukocytes to regulate T cells
What is the difference between CD28 and CTLA-4?
CD28 sends a stimulatory signal while CTLA-4 sends an inhibitory signal to T cells
What is in common between CD28 and CD40?
They are both stimulatory (CD28 stimulates T cells and CD40 stimulates APCs)
Define: a lack of reaction by the body's defense mechanisms to foreign substances, and consists of a direct induction of peripheral lymphocyte tolerance.
Anergic
Helper T lymphocyte interacts with which class of MHC-expressing APC?
MHC II class expressing APC interacts with CD4+ TH
MHC I class expressing APC interacts with which T cell subtype?
CD8+ Cytotoxic T cell
List the six molecules bound to a CD4 T cell.
LFA-1, CD4, CD3, TCR, CD2 and CD28
List the six molecules bound to a CD8 T cell.
LFA-1, CD8, CD3, TCR, CD2 and CD28
What is the main difference in signaling molecules between a helper T cell and a cytotoxic t cell?
CD4 versus CD8
What molecule interacts with LFA-1?
ICAM-1
What molecules interacts with CD4 (helper), CD3, ζ chain, and TCR?
Antigen and MHC class II
What molecules interacts with CD8 (cytotoxic), TCR, ζ chain, and CD3?
Antigen and MHC class I
List the four molecules which compose the interaction with MHC class I or class II.
CD4 helper (MHC II) or CD8 cytotoxic (MHC I), CD3, TCR and ζ chain.
What molecule interacts with C2 on T cells?
LFA-3
What molecule interacts with CD28 on T cells?
B7.1 or B7.2 molecules
What molecule serves for specific recognition of antigen?
TCR
What 5/6 molecules serves for signal transduction of the specific recognition of the antigen?
CD4/CD8, ζ chains, CTLA-4, CD2 and CD28
What three molecules serve as adhesion points?
L-selectin, LFA-1, CD2
Define: Describes any signal that is required for the activation of a naïve lymphocyte in addition ot eh signal delivered via the antigen receptor.
Costimulatory
What are the two T cell "costimulatory" molecules?
CD28 (positive effect) and CTLA-4 (negative effect)
What functions as the the signal transducing subunit of the TCR?
CD3
When a cell signals to itself and increase the affinity of LFA-1 for ICAM-1 what process has occurred?
inside out signaling
Helper T lymphocyte interacts with which class of MHC-expressing APC?
Antigen recognition/TCR engagement
What functions as an efficient means of information transfer from the APC to the T cell?
Immunological synapse and SMACs
What is the costimulatory molecule for B cells?
CD40
What is the basic function of helper T cells?
Activate other components of the adaptive response (such as B cells and macrophages)
Describe the organziation of the immunological synapse.
Composed of three concentric circles (C-SMAC, P-SMAC, and D-SMAC) each containing a peculiar mix of molecules.
Define: Proteins made by cells that affect the behavior of other cells.
Cytokine
Define: Describes a cytokine or other secreted molecule that acts on the same type of cell as the one that secreted it.
autocrine
What three cell signals are associated with c-SMAC?
TCR, CD4, CD28
What two cell signals are associated with p-SMAC?
LFA-1:ICAM-1
Define: Cytokine acts systemically in distant cells.
Endocrine
Define: Cytokine acts on neighbroing cells.
Paracrine
IL-2 secretion during T cell activation is an example of what type of cytokine?
autocrine
Chemokine recruitment of leukocytes to sites of inflammation is an example of what type of cytokine?
paracrine
IL-1, IL-6, and TNF-α are examples of what type of cytokine?
endocrine
True/False: Interleukin 2 is synthesized and secreted by the activated T cell itself.
TRUE
What is the signficance of the 3 chain structure of the IL-2 receptor?
The 3 chain has a high affinity and is expressed by activated T cells; Naïve T cell expresses a two chain IL-2.
What is required for the production of IL-2?
TCR signal and coreceptor copmlex and costimulatory signal through CD28
What is one of the functions of the co-stimulatory signal of T cell's activation?
Stabilization of cytokine mRNA to increase IL2 cytokine production 20-30 fold
What is the end result of IL-2 binding to its high affinity receptor?
Triggers the t cell to divide two to three times a day.
Describe the effects of rapamycin suppressing the immune response.
Rapamycin inhibits signaling from the IL-2 receptor disrupting T celll increased proliferation (which suppresses all immune responses that require activated T cells)
Define: Chemoattractant cytokines
chemokines
Describe the general features of cellular response to chemokines?
Directs the flow of leukocyte traffic; attraction via chemokine gradients
What viruses use CD4, ICAM-1 and CD155 as receptors to enter the host cell?
CD4=HIV, ICAM-1=Rhinovirus, CD155=Poliovirus
What are the four stages of neutrophil extravasation?
1. Rolling adhesion 2. Tight binding 3. Diapedesis 4. Migration
P-selectin, E-selectin on the endothelial wall and Carbohydrate side chain known as sialyl Lewisx are all cell interaction molecules associated with what part of neutrophil extravasation?
Rolling adhesion
Integrins LFA-1 and CR3 on the neutrophil and adhesion molecules on endothelium such as ICAM-1 (in the presence of CXCL8, chemokine) are important in what part of neutrophil extravasation?
Tight binding
LFA-1 (integrin), CR3 (integrins), CD31 on neutrophils and CD31 on the endothelium are present in which part of neutrophil extravasation?
Diapesdesis
What are the four effects of antibodies?
Opsonize, neutralize, agluttinization and complementation
CXCL8 is the cytokine (or chemokine) which mediates in what part of neutrophil extravasation?
homing
What is the molecular bases for leukocyte adhesion deficiency (LAD)?
A defect in the β2 integrin gene mutation
What are the two important functions of Innate immunity?
1. Initial response to microbes 2. Stimulates adaptive immune responses to be optimally effective against different types of microbes
Define: Microbrial substances that stiulate innate immunity which are generally conserved and universal for microbes.
Pathogen-associated molecular patterns (PAMPs)
Define: Host receptors that bind to PAMPs.
Pattern recognition receptors (PRRs)
T/F: PRRs are only expressed on the cell-surface
False, pattern recognition receptors may be secreted, cell surface expressed or intracellular.
What does activation of PRRs lead to?
Pattern recognitiion receptor activation results in secretion of proinflammatory cytokines and enhanced microbial killing.
Toll-like receptors, n-formyl-mehtionyl receptor, mannose receptors and scavenger receptors are all examples of?
Pattern recognition receptors (PRRs)
List five cellular expression product types of Toll-like Receptors (TLRs).
1. Inflammatory cytokines (TNF, IL-1, IL-12) 2. Chemokines (IL-8,MCP-1, RANTES) 3. Endothelial adhesion molecules (E-selectin) 4. Costimulatory molecules (CD80, CD86) 5. Antiviral cytokines.
TNF, IL-1, IL-12 are all examples of what?
Inflammatory cytokines
True/False as pathogens became more complex so did the immune system.
TRUE
What type of immunity is described? Slow response (days to weeks), variable, numerous highly selective specificities, improve during response.
Adaptive immunity
List the four major components of the adaptive immune response.
1. Self vs non self recognition 2. Antigen-recognition molecules 3. clonal selection 4. memory
What type of immunity is termed the first line defense?
innate immunity
What type of immunity is described? Rapid response (hours); invariant; limited number of specificities; constant during response.
Innate immunity
Whih type of immunity is considered constitutive?
Innate immunity
Which type of immunity is considered inducible?
Adaptive immunity
Induction and control (in the form of tolerance/homeostasis) refer to what immunity?
Adaptive immunity
What are the three components of induction (in the adaptive immunity)?
1. Inducibility 2. specificity 3. clonality
True/False all cells in the immune system are white blood cells (leukocytes) and derive from the hematopoietic stem cell pool.
TRUE
Cell types associated with innate immunity are mostly from the _____________ lineage.
Myeloid
Cell types associated with adaptive immunity are mostly from the ___________ lineage.
Lymphoid
What are the two arms of the adaptive immunity?
humoral and cell-mediated
Which type of cell mediates the humoral adaptive response?
B cells
Which type of cell mediates the cell-mediated adaptive response?
T cells
Which arm of the adaptive immune response deal with extracellular pathogens?
Humoral adaptive response
Which arm of the adaptive immune response deals with intracellular pathogens?
cell-mediated
Differentiate between primary and secondary lymphoid organs.
Immune cell primordial development occurs in the primary lymphoid organs (thymus and bone marrow) whereas immune cell education occurs in the secondary lymphoid organs.
List four secondary lymphoid organs.
Spleen, tonsils, lymph nodes, and peyer's patches
How are the secondary lymphoid organs further divided?
Mucosal and systemic
Describe the function of mucosal secondary lymphoid organs.
Protect against pathogens attacking the mucosa
List the four 'eyes' of pathogens (multiple routes of entry).
Ingestion, Inhalation, injection, insemination
Waldeyer's ring (lymph nodes, tonsils and adenoids), bronchus-associated lymphoid tissue, lamina propria, peyer's patch and urogenital lymphoid tissue are all examples of which division of the secondary lymphoid tissue?
Mucosal
Lymph nodes, spleen, amd mesenteric lymph nodes are all examples of what division of the secondary lymph nodes?
Systemic
The _______________ lymphoid organs serve as filters across the blood, lymph & intestines.
Secondary lymphoid organs
Granulocytes are from what lineage?
Myeloid
True/False: T cells form germinal centers inside the lymph node.
False! B cells form the germinal centers in the lymphoid follicle.
Are the T cell areas deeper (toward the medulla) of the lymph node than the lymphoid follicle?
Yes the are under the lymphoid follicle and the germinal center.
List the five classes of infectious agents.
1. Viruses 2. Fungi 3. Bacteria 4. Parasites 5. Prions
What infectious agent? Smallest infectious particle; DNA or RNA based (only one class has both); components enclosed in a protein coat with or without lipid membrane; true parasites; require host cells for replication.
Virus
What infectious agent? Univellular prokaryotes; 1-20 microns; different shapes; divide by binary fission (assexual); Gram +/-.
Bacteria
What infectious agent? Eukaryotic organisms; two forms asexual and sexual; dimorphic (asexual/sexual)
Fungi
What does dimorphic mean?
Can reproduce by either sexual or assexual means
What infectious agent? Complex eukaryotes; some unicellular, others multicellular; can range in size from tiny protozoa to 10 meter tapeworms.
Parasites
What infectious agent? Small proteinacious infectious particles; mutant form of a host protein; classified as slow virusues but they have no virion structrue or genome; resistant to chemicals, heat and ionizing radiation.
Prions
Define: Includes all members of microbial communities at individual body sites.
Microbiome
What is the primary causative agent of gastroenteritis in the US?
Salmonella
What is the primary cause of kidney failure in 1-4 year old in Canada & US?
O157:H7
Define: any substance tha may be specifically bound by an antibody molecule or a B or T cell receptor.
Antigen
How do you know that your antigen is a 'good' antigen?
It elicits an immune response.
What is the difference between a primary response and secondary response to an antigen?
Secondary response is 1) sooner 2) longer 3) bigger (greater in magnitude)
Why do we want to test antigens for their ability to induce an immune response?
Protection via vaccines
What sort of molecules make a good antigens?
Good antigens are big, complex and foreign molecules
What are the five variables that affect the immunogenicity of an antigen?
1. Dose 2. Route 3. Composition 4. Similarity to self 5. Adjuvants
What percent of pathogens are cleared from the body via the innate immune system?
95%
______________ enhance the immune responses by delaying the release of antigen.
Adjuvant
Give an example of one approved adjuvant.
Alum (Aluminum hydroxide in gel form)
Give another term for an antigenic determinant.
epitope
Define: Having multiple antigenic determinants on the surface of an antigen.
Multivalent antigens
Give two forms of multivalent antigens.
Different epitopes and repeated epitopes
Define: Small changes in cell surface antigens ie hemagglutinin and neuraminidase antigens.
Antigenic drift or mutations
Define: Segmented influenza genome among species; or major reassortment of the genome.
Antigenic shift
True/False: All antibodies are immunoglobulins.
TRUE
Antibodies are composed of how many chain molecules?
4
Describe the composition of the 4 antibody chain molecules?
2 Heavy (H) and 2 Light (L) chains covalently linked by S-S bonds
Define: A malignant disease in which one specific B cell clone multiplies repeatedly.
Multiple Myeloma
Describe the differences between the five structures of the immunoglobulin.
location of the hinge, heavy chain.
What are the two kinds of light chains?
kappa and lambda
True/False: Antibodies can contain both kappa or lambda light chains.
False, they can contain either kappa or lambda but not both.
Define: Substances that is able to provoke an adaptive immune response if injected on its own.
Immunogen
What are the four ways in which antibodies work?
1. Neutralization 2. Agglutination 3. Opsonization 4. Complement interactions
Define: Conserved molecular structures on the surface of pathogens
PAMPs Pathogen Associated Molecular Patterns
How many classes of antibodies are there?
IgA, IgG, IgM, IgD, IgE
True/False: Both L chains and H chains have variable & constant regions.
TRUE
Each V region and C subregion of an antibody constitutes a __________.
Domain
Distinguish between hypervariable regions and framework residues.
Hypervariable regions can change dramatically to fit a specific antigen; framework residues form the foundation for the hypervariable regions
List the regions of the antibody that make it a useful reagent for immunological assay.
Highly variable/highly specific light chains, non-antigen binding region is available for chemical coupling to "reporter" molecules.
ELISA, Radio-immunoassay (RIA), FACS , immunofluoresence, western blot, and coombs test are all what type of immunological methods?
Antibody-based methodologies
List two types of clelular assays.
Proliferation assay and cytotoxicity assay
List two nucleic acid-based assays.
Southern blot and microarray ("Gene chip") analyses
Pathogens, pathogen products, or serum antibodies are examples of antigens detected in what antibody-based immunoassay?
ELISA
When target is in low concentration, such as hormones, what is the preferred antibody-based immunoassay?
Radio-immunoassay (similar to ELISA)
Cell surface proteins (markers of activation state, cell type) and internal proteins (e.g. cytokines, cytoplasmic signaling molecules) are examples of antigens which are detected in what antibody-based immunoassay?
FACS analysis
In addition to FACS analysis what other antibody-based immunoassay could be used to detect cell surface proteins and internal cellular proteins?
Immunofluorescence
Cellular proteinsor pathogen proteins, typically in a denatured form, are antigens detected by what antibody-based immunoassay?
Western blot
Cell surface antigens (RBCs) are detected via what type of antibody based immunoassay?
Coombs test
What does ELISA stand for?
Enzyme Linked Immunosorbent Assay (ELISA)
What test: an unknown amount of antigen is affixed to a surface, and then a specific antibody is washed over the surface so that it can bind to the antigen. This antibody is linked to an enzyme, and in the final step a substance is added that the enzyme can convert to some detectable signal. Thus in the case of fluorescence test name, when light of the appropriate wavelength is shone upon the sample, any antigen/antibody complexes will fluoresce so that the amount of antigen in the sample can be inferred through the magnitude of the fluorescence
ELISA
What is the criteria for protective immunity to a particular antigen?
titer >= positive control
In RIA, the amount of radioactivity is _________ proportional to the concentration of hormone in the positive sample when compared with a negative sample.
Inversely
What does FACS stand for?
Fluorescence activated cell sorting
List the three optical properties of particles (cells).
Cell size (scatters light), Cellular granularity (scatters light), and fluorescence (fluorochrome-labeled antibody detection)
What type of immunoassay is being described here? It provides a method for sorting a heterogeneous mixture of biological cells into two or more containers, one cell at a time, based upon the specific light scattering and fluorescence characteristics of each cell. It is a useful scientific instrument, as it provides fast, objective and quantitative recording of fluorescent signals from individual cells as well as physical separation of cells of particular interest.
FACS analysis
What type of immunoassay separates proteins via electrophoresis then detects specific proteins via antibody-enzyme color?
Western blot
T/F: Western Blot requires the separated proteins be transferred from a polyacrylamide gel to a different membrane for further evaulation?
True, polyacrylamide gel is used for electrophoresis, the nitrocellulose gel is used for diagnostic testing.
What test: Used for detection of anti-RBC antibodies bound to RBCs in an individual patient.
Coombs test.
What est would you order for a patient which you suspect has an autoimmune hemolytic anemia?
A direct coombs test because there will be RBC/antibody complexes which cause RBC destruction and the resulting anemia
Differentiate between a direct Coombs test and an indirect Coombs test.
A direct Coombs test detects antibodies already attached to a person's own blood while an indirect coombs test determines whether the serum of another person while react with the patient's RBC
What type of Coombs test? a blood sample is taken and the RBCs are washed (removing the patient's own plasma) and then incubated with antihuman globulin (also known as "Coombs reagent"). If this produces agglutination of RBCs, the ______ Coombs test is positive, a visual indication that antibodies (and/or complement proteins) are bound to the surface of RBCs
Direct Coombs test
Define: Antihuman globulin used in the direct Coombs test.
Coombs reagent (such as Rabbit anti-human immunoglobulin)
List three ways antibodies for clinical assays are obtained.
Patient sera (blood draw), polyclonal antibodies (animal immunization), monoclonal antibodies (hybridomas)
Blood draw is associated with what source of antibodies?
Patient serum
Polyclonal antibodies are produced from what source?
Immunized animals
Monoclonal antibodies are produced from what source?
Hybridomas (immunization of rodents, followed by fusion of reactive spleen cells with tumore cells.
What source of antibody should be used? Used when the patien response to an antigen needs to be assessed.
Patient sera (blood draw)
What source of antibody should be used? Typically used when an antigen needs to be detected with maximal signal (e.g. anti-human antibodies for ELISA detection)
Polyclonal antibodies (rodent immunization)
What source of antibody is described? Typically used when antigen needs to be detected with exquisite specificity.
Monoclonal antibodies (rodent immunization followed by hybridoma)
List an advantage and a disadvantage of using monoclonal antibodies.
Advantage: Great purification value Disadvantage(s): Highly specific, laborious to produce
List an advantage and a disadvantage of using polyclonal antibodies.
Advantage: Cheap to produce Disadvantage: Difficult to purify
Give a specific example where monoclonal antibodies are used in treatment.
anti-TNF-alpha mAbs are used as drugs to treat rheumatoid arthritis
Why is molecular biology required to produce mAbs for humans?
It is very difficult to generate human antibodies
What type of immunoassay? Used to measure the ability of B cells or T cells to proliferate in response to mitogenic stimuli.
Proliferation assay
Where are polyclonal antibodies isolated from?
Serum (murine or other lab animal)
What type of immunoassay is described? B or T cells are placed in tissue culture with radiolabeled nucleic acids and a mitogenic stimulation. After several hours of growth, excess label is washed out, and cells are harvested. Measurement of incorporation of radiolabel allows the proliferative response to be quantified.
Proliferation assay
What test would be ordered? Various tests have failed to indicate a pathogen infection (AIDS has been ruled out); FACS shos the patient has normal numbers of T cells.
Proliferation assay which reveals that in response to various T cell mitogenic stimuli, Patient #1 shows little or no T cell proliferation.
CD3, CD28, IL2 are all examples of what type of signal for B or T cells?
Mitogenic signals used in the proliferation assay.
In a cytotoxicity assay (chromium release assay); what is being measured?
The efficient of the effector cells
What type of immunoassay? Target cells are loaded with radioactive chromium, effector cells are added into the solution; incubation; media removed and percent of radioactive chromium in the media is calculated to determine % specific lysis.
Cytotoxicity assay: Chromium release assay
What type of test would you order when you suspected T cell numbers are good and proliferating but they are failing to activate?
Cytotoxicity assay: Chromium release assay
What test is used in clinical immunology specifically for the detection of specific chromosomal rearragnements, partciularly in lymphocyte tumors.
Southern blot
Which immunoassay is being described? 1. Separation of endonuclease-digested DNA fragments 2. Transfer of DNA to a nylon membrane 3. Hybridaization to a specific radiolabeled DNA probe. 4. Exposure to X-ray film to visualize specific DNA fragments.
Southern blot
When you suspect DNA or want to characterize a tumor better what method of immunoassay would you perform?
Southern blot
What immunoassay provides simultaneous analysis of expression of thousands of genes concurrently?
Microarray ("Gene chip") analyses
What test is being described? Glass slide is prepared with DNA sequences from individual genes; two samples (normal and patient) are put through reverse transcriptase to form mRNA; Patient and control are fluorscently dyed differently; Patient and Control differently dyed mRNA is competitively hybridized with the DNA prepared glass slide; data is collected on fluorescent status of each spot.
What assay should be used? Desire for unique genetic information, determination of carrier status for cystic fibrosis; snapshot of cancer's expression of different genes.
Microarray ("Gene chip") analyses
List the four major groups of cellular adhesion molecules (CAMs).
1. Immunoglobulin Superfamily 2. Integrin family 3. Selectin Family 4. Vascular addressins
Which family of CAMs? ICAM-1, ICAM-2, CD2, CD4, CD8. Structures based on immunoglobulin fold.
Immunoglobulin superfamily
Which family of CAMs? LFA-1; heterodimers of alpha and beta chains; subfamilies named after shared beta chain.
Integrin family
Which family of CAMs? Extracellular portion of molecule terminates in a lectin domain; binds to carbohydrate ligands, facilitating interactions between leukocytes and endothelial cells; L-selectin
Selectin family
Which family of CAMs? Molecules bearing the carbohydrate ligands that are recognized by L-Selectin; such as CD34, GlyCAM-1
Vascular addressins
What is it? The antigen receptor on b cells which is a membrane bound immunoglobulin molecule.
B cell receptor
What is it? The highly variable antigen receptor of T lymphocytes composed of a variable alpha chain and a variable beta chain; known as the alph:Beta t-cell receptor.
T cell receptor
What molecule? Complex of signaling proteins that associates with T-cell receptors. Consists of CD3γ, δ, ε, and ζ chains
CD3
What molecule? Adhesion molecule on T cells that binds to the LFA-3 adhesion molecule on antigen-presenting cells.
CD2
What molecule? Cell-surface glycoprotein that distinguishes a subset of t cells that recognize antigens present by MHC class II molecules.
CD4
What binds to MHC class II molecules on the antigen-presenting cell and acts a s a co-receptor to augment the T cell's response to antigen?
CD4
What molecule? Cell surface glycoprotein that distginsuiches a subset of t cells that recognize antigens presented by MHC class I molecules.
CD8
What binds to MHC class I molecules on the antigen-presenting cell and acts as a co-receptor to augment the T cell's response to antigen?
CD8
What molecule? The low-affinity receptor on T cells that interacts with B7 co-stimulatory molecules to promote T-cell activation.
CD28
What molecule? Vascular addressin that is expressed on high endothelial venules in lymph nodes and is involved in the extravasation of white blood cells?
CD34
What molecule? Cell -surface glycoprotein on B cells whose interaction with CD40 ligand on helper T cells triggers B-cell proliferation.
CD40
What molecule? T cell Ligand protein which interacts with CD40 cell-surface glycoprotein on B cells whose interaction triggers B cell proliferation.
CD40L
What molecule? Vascular addressin present on the high enothelial venules of secondary lymphoid tissue. It is an important ligand for the L-selectin adhesion molecule on naïve lymphocytes and directs these cells to leave the blood and enter the lymphoid tissues.
GlyCAM-1
What is an important ligand for the L-selectin adehsion molecule on naïve lymphocytes and directs these cells to leave the blood and enter the lymphoid tissue?
GlyCAM-1
What molecule? Co stimulatory molecules present on the surface of professional antigen-presenting cells such as dendritic cells; examples B7.1 and B7.2 proteins.
B7 molecules
What molecule? High-affinity inhibitory receptor on T cells that interacts with B7 co-stimulatory molecules.
CTLA4
What two molecules (a high and low affinity) interact with B7 co-stimulatory molecules on professional antigen presenting cells.
CTLA4 (high affinity) and CD28 (low affinity)
Give names for three different types of intercellular adhesion molecules.
ICAM-1, ICAM-2, ICAM-3
What molecule? Cytokine produced by activated T cells that is essential for the proliferation of activated T cells and the development of and adaptive immune response.
Interleukin-2