1 Macmillan Learning 2023

Anotacoes

© Macmillan Learning 2023 Innate Immunity Fig. 4-1 © Macmillan Learning 2023 Innate and Adaptive Immunity Attribute Innate immunity Adaptive immunity Response time Minutes/hours Days Specificity Specific for molecules and molecular patterns Shared among classes of pathogens and for molecules produced by dead/damaged cells. Highly specific; discriminates between even minor differences in molecular structure of microbial or nonmicrobial molecules. Diversity A limited number of conserved, germ line–encoded receptors. Highly diverse; a very large number of receptors arising from genetic recombination of receptor genes in each cell. Memory responses Trained immunity in some innate cell types enables stronger responses following initial exposure to antigen. Specificity of trained immune responses is broad. Persistent memory, with faster response of greater magnitude on subsequent exposure Self/nonself discrimination Essentially perfect; no microbe-specific self/nonself patterns in host. Receptor repertoire determined over evolutionary timescale. Very good; occasional failures of discrimination result in autoimmune disease. Receptor repertoire subject to mutation and selection dur...