Microbiology and Immunology 3300B Lecture : Immunology Notes
20 Feb 2012
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Innate receptors: inherited in the germ-line, expressed by all cells of a particular type, triggers immediate response, recognize broad classes of pathogens (degenerate), and interact with a range of molecular structures (pamps) of a given type. Adaptive receptors: encoded in multiple gene segments, require gene rearrangement, clonal distribution, and able to discriminate between closely related molecular structures. Pathogen-associated molecular patterns (pamps): molecules found only in pathogens. Pamps will be present on a broad range of pathogens (common to lots of different pathogens). They are evolutionarily conserved (won t change over time because this would be harmful to the pathogen). Common bacterial pamps: the cell walls of gram-positive bacteria contain lipoteichoic acid and peptidoglycan. The cell walls of gram-negative bacteria contain lipopolysaccharide. These components are not found in animal cells. In human dna, the c of cg pairs is methylated so we can recognize our own dna. In pathogens, cg isn t methylated, so we know it s foreign.
