IMM250H1 Lecture Notes - Lecture 2: Monocyte, Amphiphile, Neutrophil
Document Summary
Skin and mucosal surfaces: specialised mechanisms of defense. Plan b: innate response: humoral components: complement, coagulation system, cytokines, cellular components: epithelial cells, neutrophils, monocytes and macrophages, Respiratory tract: ciliated cells and mucus (made by goblet cells), trap and shunt debris up and out. Gut: non-ciliated, microvilli-increase surface area preventing microbes from touching epithelial surface-, mucus (goblet cells), antimicrobial factors (defensin-paneth cells-make holes in bacteria), peristalsis. Defensins are amphipathic peptides, (+) region binds to (-) charged microbe membrane hydrophobic region inserts into membrane destroying it. Produce cytokines, chemokines, transport antibodies (iga) from inside out. Eyes/nose/oral cavity: lysozymes-attacks pg in bacteria cell wall. *mechanical: epithelial cells joined by tight junctions, cilia movement, tears, flow of fluid/air. *chemical:fatty acids, enzymes, low ph, surfactants, lysozymes, defensins. Antibiotics overgrowth of less common bacteria (candida, c. diff) Normal flora to abnormal sites ( e. coli in urinary tract, perforated appendix) Probiotics are live bacterial cultures (assumed to be beneficial)
