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18 Cards in this Set
- Front
- Back
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What is a cytokine? |
A small protein made by a cell that affects the behavior of other cells. |
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What is an interleukin (IL)? |
Cytokine made by a lymphocyte. |
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What is a chemokine? |
Chemo-attract protein that stimulates cell migration (and activation) e.g of phagocytes, lymphocytes |
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Which cell produces IL-2? |
T cells
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Which cell produces IL-y ? |
T cells and NK cells |
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Which cell produces IL1 and TNFa? |
Macrophages (and T cells) |
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How do stimulated T cells make IL-2? |
Activated (b, y and NEW a chain) T cell express a high-affinity IL-2 receptor and secrete IL-2
Binding of IL2 to receptor signals T cell to enter cell cycle Induces T cell proliferation |
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How does IFN-y signal? |
JAK-STAT pathway
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What does IFNy do? |
Anti-proliferative
Regulates differentiation Induces MHC antigens Activates NK cell and macrophages |
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How to viruses target IFN-y? |
Pox viruses -produce soluble IFN-y receptor homologues - T7, B8-R
Mop up IFN-y and prevent MHC gene activation Other viruses, produce proteins that block JAK-STAT |
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What is inflammation a result of? |
Inflammation is often, but not always a result of infection. |
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What cytokines do macrophages produce? |
IL-1B - activates lympocytes and vascular endothelium - fever and production of IL6
TNF-a - fiver, mobilises metabolites |
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What is the effect of TNFa and IL1? |
Liver - acute-phase proteins, MBL, C-reactive
BM endothelium - neutrophil mob - phag Hypothal - inc. body temp. - decreases viral/bacterial replication, increased antigen processing Fat, muscle - protein and energy metabolism -inc. body temp Dendritic cells - TNF-a stimulates migration from lymph nodes - adaptive immune response |
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What is TNF-a? |
Tumour necrosis factor Cytokine binds to homotrimeric receptor. Secreted by macrophaes Stimulates proliferation and induces cell diff. |
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How does TNF-a signal? |
MAP/ERK kinase kinase Can activate cleavage of pro-caspase 8 or NFkB released into nucleus |
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How does NFkB reach the nucleus? |
Activated IKK phosphorylates IkB IkB degraded - releases NFkB |
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What is IL-1? |
Interleukin 1 Produced by activated macrophages Stimulates thymocyte proliferation by inducing IL-2 release, B-cell maturation and proliferation, and fibroblast growth factor activity Stimulates the release of prostaglandin and collagenase from synovial cells |
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How is IL-1 processed and secreted? |
(Calcium-dependent cys protease) Calpain (IL1a) or ICE (IL1b) to active form ICE is a prototypical caspase |
