BIO1022 Study Guide - Final Guide: Pattern Recognition Receptor, Natural Killer Cell, Tlr5
Document Summary
E. g: skin: physical barrier, lysozymes in tears, mucus in respiratory tract, cilia, low ph of stomach. Recognise pamps (pathogen associated molecular patterns) such as flagella, dsrna. Lacks specificity- same response for all pathogens and lipopolysaccharides. Important for the survival of the pathogen, so cannot easily evolve removing them, making them a target for immune cells. Recognised by pattern recognition receptors such as toll-like receptors (tlr) When a pamp is recognised, phagocytosis occurs. Internalisation of a large particle into a specialised compartment. Accomplished by phagocytic cells such as macrophages and neutrophils. The pathogen is broken down with enzymes, free radicals or hydrogen peroxide. Can detect infected cells, and kill them to stop pathogen replication. Normal cells give both an activating and an inhibitory signal to nk cells. In the absence of an inhibitory signal, the nk cell will kill the affected cell. Full of granules containing toxic agents such as proteases and reactive oxygen intermediates.
