Microbiology and Immunology 2500A/B Lecture Notes - Lecture 2: Adaptive Immune System, Lysosome, Phagolysosome
15 Mar 2018
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Document Summary
Innate immunity: key properties of innate immunity, how barriers prevent pathogen entry into tissues, how the innate immunity system recognizes and binds pathogens. Innate immunity is the first line of defense against a pathogen. It is constantly ready to destroy a pathogen: effective at stopping majority of pathogens at early stage. Innate immune defenses: barriers: block pathogen entry into tissues if (cid:271)a(cid:396)(cid:396)ie(cid:396)s do(cid:374)"t (cid:449)o(cid:396)k, (cid:373)ust (cid:396)el(cid:455) o(cid:374) i(cid:374)(cid:374)ate (cid:272)ells a(cid:374)d p(cid:396)otei(cid:374)s. Innate cells and proteins: rapidly eliminate pathogens that enter tissues. If innate immunity is unsuccessful: certain innate cells initiate adaptive immunity to help eliminate the pathogen (works alongside each other) Innate immunity happens immediately: adapti(cid:448)e i(cid:373)(cid:373)u(cid:374)e s(cid:455)ste(cid:373) does(cid:374)"t (cid:271)e(cid:272)o(cid:373)e effe(cid:272)ti(cid:448)e up to (cid:1011)-10 days after first exposure, long time to develop. Defensins: broad spectrum pore-forming (in cell membrane) antimicrobial peptides, kill bacteria, viruses, fungi. Innate immune system all have defensins (co-evolving), but microbes have not developed to inhibit defensin from attacking them: mechanism, efflux of nutrients, essential ions, etc.
