IMM350H1 Lecture Notes - Lecture 3: Fas Ligand, Perforin, Interleukin 4
Document Summary
Killing by ctls is mediated by infected by pathogen perforins and granzymes: cytotoxic effectors: perforin, granzymes, granulysin, fas ligand, others: ifn- , lt- , tnf- . Dna fragmentation -> ctl migrates to new target -> target dies by. Initial cd8+ target + t cell interaction is non-specific -> cells will separate apoptosis. Perforin: aids in delivering contents of granules to cytoplasm of target. Antigen-specific recognition -> cell death of target & release of cd8+ t cell: cytotoxic granules: Cytoplasmic components & cytoskeleton redistribute, granules released: selective killing: cell programed for death. Granzymes: serine proteases which activate apoptosis once in the cytoplasm of the target cell. Grranulysin: has antimicrobial actions and can induce apoptosis. Signal 3 induces distinct types of effector cd4 cells. Il-4: th2 (parasites) produce cytokines, these induce transcription factors in na ve t cells. Antimicrobial responses are highly coordinated by th1 cells. Ifn- and cd40 ligand: activate macrophage to destroy engulfed bacteria.
