MICR 3230 Chapter : Chp 14 Cell-Mediated Cytotoxic Responses
Document Summary
Ctls induce death via: perforin/granzyme pathway and fas/fasl pathway. Non-specific cytotoxic cells (nk cells, neutrophils, eosinophils, macrophages) also kill target cells. Cells bind the fc region of antibody on target cells and release lytic enzymes, perforin or tnf to damage membrane antibody-dependent cell-mediated cytotoxicity (adcc) Nk cells mediate lysis of tumor cells and virus infected cells by perforin-induced pore formation, similar to ctl mechanism. Nk cell receptors fall into: lectin-like or ig-like. Nk cell receptors transduce signals via itams(activating) or itims (inhibiting) High levels of class i mhc molecules on normal cells protects them against nk cell killing.