Page 584 - Veterinary Immunology, 10th Edition

use RORγt as their transcription factor and their maintenance and
VetBooks.ir function depend on signals from the aryl hydrocarbon receptor

(AhR) (see Box 21.1).
ILC3s produce IL-17 and IL-22 in response to stimulation by

TSLP and IL-23 and thus resemble Th17 cells in their cytokine
profile (Fig. 19.4). They play a central role in immunity on mucosal
surfaces by resisting extracellular bacteria and fungi. They do this
by producing IL-22. On exposure to IL-22, enterocytes produce

antimicrobial proteins that protect the intestinal epithelium. ILC3-
derived IL-22 also inhibits T cell-mediated intestinal inflammation
by inactivating those that respond to antigens from commensal
bacteria. This IL-22 from ILC3s also inhibits the growth of

segmented filamentous bacteria (Chapter 21).

FIG. 19.4 The functions of Group 3 innate lymphoid cells.
Microbial products stimulate cDC2 cells to produce IL-23 and IL-1β.

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