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Immunology (Subject) / Innate IS (Lesson)
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- Physical Barriers Skin, pH, fatty acids, commensal bacteria, shedding
- What are PAMPs? Pathogen associated molecular patterns
- Neutrophil extracellular traps vomit DNA on bacteria to glue them together
- Complement: Classical IgG/IgM on bacteria surface C1rC1s cleaves C4 into C4a+C4b / cleaves C2 into C2a+C2b C4bC2a = C3 convertase
- Complement : lectin Mannose recognized MBL (mannose binding lectin) C4/C2 into C4a+C4b / C2a+C2b C4bC2a = C3 convertase
- Complement: alternative pathogen binds C3 -> hydrolysis D cleaves B into Bb+Ba C3b+P+Bb = C3 convertase
- Complement: terminal C4bC2aC3b / 2C3bBb = C5 convertase C5 into C5a + C5b C5b recruits C6+C7+C8 multiple C9 form super mario tube
- Phagocytes methods of killing bacteria 1) lysozyme and anti microbial peptides 2) respiratory burst ( O2-> H2O2-> HOCl) 3) nitrosative burst (NO+H2O2-> peroxynitrites)
- DC: 3 Signals of activation 1) receptor recognition (MHC : TCR) 2) co-stimulation ( CD80/CD86 : CD28) 3) cytokines ( IL12 / IL4 )
- Innate immune response to Viruses Type I IFNα+β by plasmacytoid DC and infected cells
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- Natural killer cells lack of MHC I or stress signals (DAMP) lyse cell by perforin-granzyme perforin = pore granzyme = activate DNAse produce IFNγ + TNFα kill via ADCC
- NKC : ADCC antibody dependent cell-mediated cytotoxicity FcγRIII binds IgG
- Macrophages eat infected cells produce TNFα , NO3 and IFNα