PHGY 209-immunology lecture V

PHGY 209-immunology lecture V - These molecules cause the...

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PHGY 209-Immunology Lecture V October 18, 2008 Memory B and memory T cells are deposited in the regional lymph nodes. Immunization with live virus give you lifelong immunity. Tetnus- does not. Only last for about 4 years, Cytotoxic T cells CD8 +, not natural killers. Must be taught to kill. Need assistance by CD4+ TH1 helper cells. Immunoglobulin and T cell receptor are formed randomy in the utero and not in response to any antigenic stimuli. CD4 helps in MHC II binding, CD8 helps in MHC I binding. Clonal selection (+)/Clonal deletion (-): Need to destroy cells that see us. In terms of the thymus, 95% of the T cells are killed in the thymus. Defense against virus: Dendritic cell takes virus up by phagocytosis and cut it up into little pieces and present it on its surface. MHC II complex with B7 coreceptor binds with TH1 cell. TH1 cell is activated. We find out that the helper cell is a TH1 because it secretes INF (interferon) and IL 2 rather than IL 4, 5, 6.
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Unformatted text preview: These molecules cause the proliferation and further maturation of the cytotoxic T cells that will kill the infected cells in order to stop the proliferation of the infection. Infected cell and cytotoxic cell meet through MHC1 complex and T cell receptor. Cytotoxic T cell kills it and goes back as a memory cell. Thymus of the utero Remove from thymus T cells that will not recognize MHC (they can’t do anything) Remove from thymus that sees the MHC complex too well. (Binds too well to MHC may make antiself antibody)- dangerous. We want cells that can recognize MHC “pretty well” – can bind but not too dangerous Epithelial component of the thymus are able to construct proteins of any conformation- both self and foreign. This allows T cells to see all the foreign cells and all the self cells. Lymphoepithelian organ....
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This note was uploaded on 12/25/2008 for the course PHGY PHGY 209 taught by Professor Annwechsler during the Spring '08 term at McGill.

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