BIOM20001 Lecture Notes - Lecture 56: Thymus, Cytosol, Macrophage
Document Summary
Complement also acts on vasculature and cells to cause inflammation. Encode soluble cytokine receptors (eg tnf r): blocks endothelial cell cytokine signalling (eg vaccinia virus) Inhibit adhesion molecule expression: blocks leucocyte adhesion to infected cells (eg epstein-barr virus. Produce complement receptors: depletes complement intermediates (eg hsv) Degrade complement components: c3b (staph. aureus) and c5a (pseudomonas, Inhibit the formation of the membrane attack complex: inhibits lysis, cell death, eg vaccinia virus. The production of a capsule: electrostatic repulsion mask underlying structures (str. pneumoniae) Coating the microbe surface with human proteins: resemble host components, thus no antibody induction eg streptococcus pyogenes, treponema pallidum schistosomes. Some infectious agents evade killing (typically the intracellular agents) Inhibit the respiratory burst, inhibit acidification of phagosome: salmonellae. Inhibit fusion of the phagosome: reduced access to lysosomal contents, eg mycobacterium tuberculosis, toxoplasma gondii) Escape from the phagolysosome to the cytosol: unrestricted growth (but cd8 t cells may become activated, eg listeria monocytogenes)
