Page 286 - Veterinary Immunology, 10th Edition

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FIG. 10.7 Two populations of cDCs activate helper T cell
subpopulations. cDC1 cells promote type I responses by producing
IL-12 and activating Th1 cells. Whereas cDC2 cells promote type II
responses by producing IL-6 and IL-23 and so activating Th2 cells
and Th17 cells. The helper cell population that is activated depends
on the cytokine mixture produced by these dendritic cell
subpopulations. The specific dendritic cell subpopulations activated
depend upon the nature of the inducing antigens. Dendritic cells
also activate innate lymphoid cells (ILCs). cDC1s activate ILC1s
and cDC2s activate ILC3s (Chapter 19).

Different PAMPs and DAMPs acting through different TLRs
influence the development of these dendritic cell subpopulations
and thus the types of responses induced. The stimuli that promote
cDC1 production include double-stranded RNA acting through
TLR3, lipopolysaccharide acting through TLR4, flagellin acting

through TLR5, and nucleic acids acting through TLR7 and TLR9.

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