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9 Cards in this Set
- Front
- Back
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What Ig isotype is involved in the first encounter?
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IgM
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What are the roles of antibodies?
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Opsonisation
Bacterial killing Neutralisation of toxins Prevent attachement at mucosal surfaces (IgA) Agglutination of bacteria (IgM) Eosinophil mediated parasite killing (IgE) |
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Which chromosomes encode heavy, kappa and lambda chains?
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14,2,22
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What parts of the antibody lend to its variation and specificity?
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Variable chains and their hypervariable regoins
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Explain affinity maturation
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When antigen concentration are high even low affinity B-cells and their low affinity antigen are stimulated to proliferate etc. However as the levels of antigen fall only the high affinity B-cells are continually stimulated and so these begin to predominate leading to high affinity Ab for that particular antigen
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Where are MHC I and II types found and which major HLAs belong to each class?
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I - All nucleated cells - HLA-A,B,C
II - APC cells only - HLA,DP,DQ,DR |
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How is central tolerance achieved?
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CD8+ must have some affinity for MHC I to be presented to by it but not enough to attack self without antigen presentation.
CD4+ same but for MHC II |
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What co-stimulatory signal is need to activate CD4+ cells and which cells supply this signal?
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B7-1/2 supplied by APCs like dendritic cells, B-cells or macrophages. This signal stimuates CD28 which must be stimulated alongside the TcR to active.
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How does T-cell anergy improve self tolerance?
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If a naive T-cell comes across an APC not expressing the co-stimulatory signal and interacts with it and the self antigen (hence why no co-stim), it becomes Anergised making it unresponsive to further antigen presentation improving self tolerance further
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