91401 Lecture Notes - Lecture 8: Interferon Gamma, Natural Killer Cell, Perforin
Document Summary
Cytotoxic t cells: kill cells infected with viruses or intracellular pathogens, produce perforins and granzymes, similar killing mechanism as nk cells, mainly produce interferon gamma (ifn-) (that blocks viral replication, increase mhc-i expression and activate macrophages) T cell killing: cd8+ t cell clones (small cells) killing cervical carcinoma cells (large cells). Attached t cells deliver the "kiss of death", inducing the cancer cells to undergo apoptosis: cell apoptosis. This is the mechanism by which cytotoxic t cells kill their target cells. Promotes inflammation and can release intact pathogens. Nucleases that drive cellular dna destruction also destroy viral dna. Fas fas-ligand (fasl) (cd95 cd178) pathway: b and t cell activation & pro-inflammatory cytokines (e. g. ifn, tnf) increase. Ctls (and nk cells): on recognition of target cell, granules are released, on recognition of target cell, granules are released. Extrinsic death receptor mediated, intrinsic mitochondrial mediated: t helper cells, cytokines bind to receptors on immune cells that activate/suppress and help.
