BIOL 2005 Lecture Notes - Exocytosis, Death Domain, Superoxide
30 Jan 2013
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Document Summary
Ctls lyse target cells that display processed foreign antigens bound to mhc molecules. Pathogens replicating within host cells are protected from humoral immune response by intracellular environment. But peptide products appear on mhc i and are recognized by cd8 + ctls. Ctls can eliminate infected cells even in the presence of excess soluble antigen. Functions virally infected cells (major) tumor cells bacterial infected cells graft rejection. *important that their activity is confined only to target cells* Note: some cd4 and some nk cells also have cytolytic activity. Intravenous transfer of cd8 t cells specific for flue can protect against viral pneumonia! Ctls can recognize conserved np abundantly synthesized on the cytoplasm (thus catches ha/na antigenic shift) Class i (b-2microglobluin) and cd8 knockouts reduced ctl levels and don"t clear virus. Perforin knockouts normal cd8+ numbers but don"t lyse virally infected cells. Perforin plays central role in lysis of target cells by ctl.
