Term
| Where do the majority of infectious diseases originate? |
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Definition
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Term
| How do commensal bacteria exclude pathogens? |
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Definition
prevent pathogens from colonizing the host
compete for space, oxygen tension, pH etc with pathogens |
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Term
| How do commensal bacteria influence lymphocyte function? |
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Definition
| APCs regularily sample commensals as they are sampling antigens, helps to regulate the local immune response against commensals & food (don't want to react to commensals in your gut, or 'good' things you eat) |
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Term
| How do organisms get to lymphoid tissue? |
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Definition
-direct invasion
-spcialized M cells (they don't have a brush border, less mucus)
-epithelial cells (often phagocytic)
-direct capture by dendritic cells |
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Term
| Inductive vs effector sites |
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Definition
Inductive site - antigens are processed and an immune response is initiated here
Effector sites - this is where antibody and cell mediated responses are generated |
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Term
| What is the significance of B cell affinity for all mucosal surfaces |
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Definition
B cells that produce IgA are present at all mucosal surfaces
-priming of an antigen at one location will result in generation & secretion of antibodies at remote locations |
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Term
| What is immune exclsion (IgA, IgM) |
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Definition
| IgA - opsonization, virus neutralization |
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Term
| ______ cells located directly over Peyer's patches have less mucus and no brush border, so they are a 'weak point' in the front lines of defense |
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Definition
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Term
True or False
IgA activates the complement system |
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Definition
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