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6 Cards in this Set
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Complement - describe it. Is it innate?
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One of the complement pathways is innate - the alternative pathway.
the alternative is the first to act after infection and is always kinda on. It's turned on by LPS. Immediately cleaves C3 into C3a and C3b. Note that C3b is the "binding" one that performs OPSONISATION for improved phagocytosis. C3a recruits phagocytes. Note that the complement system can also blow holes in enemy membranes by membrane attack complexes. (MAC's) |
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how many kinds of opsonisation are there?
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2 kinds - one from antibody binding to enemy which then binds to phagocyte, and another from C3b.
note that when working together, phagocytosis response is turned way up. |
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what "soluble mediators" do they want us to be familiar with?
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anti viral defense - mediated by the interferons (INF alpha and INF gamma
complement proteins inflammation (pro inflammatory = IL1, IL6 and TNF |
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describe the cell's antiviral response.
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Interferons "interfere" with viruses and confer protection to adjacent cells, so they won't get infected.
NK cells come by and check for infection - if so, they blast holes in them. Then, you get a T-cell response (CD8's to come by and further kill bad cells). Then, you get a B cell response to make anti-viral antibodies. This is considered seroconversion. So, first is INF, then NK's, then T-cells. |
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describe interferons better:
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two classes: type 1 includes INF alpha and Beta. These are involved in ANTIVIRAL ACTIVITY.
INF beta is released by T cells and is a big activator of macrophages. Not good against viruses, but ups MHC1 and MHC2. |
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what are the two big cytotoxic cells and what are their main differences?
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Cd8 T cells and NK cells.
Big difference is that T cells require MHC, NK's don't. This is why NK's are part of the innate immunity and T cells aren't. NK cells work by recognizing inhibitor molecules on healthy cells and NOT killing. If the cell is infected, none of those are present and the NK kills. Also, INF alpha and beta up the NK activity. Biggest antiviral activity is that NK's bind to uninfected cells and induce synthesis of enzymes that inhibit viral protein synthesis. |
