91401 Lecture Notes - Lecture 1: Necrotizing Fasciitis, Antimicrobial Peptides, Phagosome
Document Summary
The phagosome becomes acidified, fuses with lysosomes, and kills the microbe. Internalized microorganisms and lysed products are recognized by pamps (pathogen- associated molecular pattern receptors). Neutrophil extracellular traps (nets: nets are formed by activated neutrophils. Contain a dna backbone with antimicrobial peptides and enzymes. Involved in defence against a number of extracellular organisms including neumococcal pneumonia and streptococcal necrotizing fasciitis. When a macrophage encounters an extracellular microbe: microbe is coated in humoral mediator e. g. complement proteins, macrophage captures microbe by: prr complement receptor ligation of. Prrs lead to signalling events that result macrophage expression of proinflammatory cytokines, also macrophage begins to express more lysosomes: microbe is phagocytosed, lysosomes fuse with phagosome, contain enzymes, oxidases pump free radicals into phagolysosome, microbe is digested. Microbe derived peptides are transported via mhc proteins to the cell surface and presented to t cells (adaptive immunity) 6-7. In blood they are massive producers of ifnb (plasmacytoid dcs)
