BIOL 1221 Lecture Notes - Lecture 14: Natural Killer Cell, Adaptive Immune System, Phagocyte
22 Jun 2017
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Ch:20: phagocytes, nk cells, antimicrobial proteins, and fever to the functioning of innate defenses. Phagocytes: white blood cells that ingest and digest (eat) foreign invaders. Neutrophils : most abundant, but die fighting. Become phagocytic on exposure to infectious material. Macrophages : develop from monocytes, chief phagocytic cells; most robust phagocytic cell. Free macrophages : wander through tissue spaces searching for cellular debri; e. g. alveolar. Fixed macrophages : permanent residents of some organs; e. g. stellate macrophages ( liver ) and microglia ( brain ) Opsonization ( process of u(cid:374)dergoi(cid:374)g phagocytosis) : antibodies or complement proteins are opsonins ( (cid:373)olecules that help i(cid:374) the process of opso(cid:374)iza(cid:415)o(cid:374)) that coat pathogens. Act as handles for phagocytes to grab on to, enhancing phagocytosis. Activated phagocytes may release a series of antimicrobial agents: Antimicrobial enzymes, e. g. defensins (in pmns)- pierce pathogen"s membrane. Free radicals (e. g. no, superoxides) and oxidizing chemicals (e. g h 2 o 2 , bleach) generated via.
