IL-23 is a cytokine made by macrophages and dendritic cells in response to extracellular bacterial and fungal infections. Mice with a genetic defect in the production of IL-23 are highly susceptible to the gastrointestinal bacterial pathogen, Citrobacter rodentium. Thus, unlike wild-type mice which clear the infection, mice that fail to produce IL-23 succumb to the bacteria and die 1-2 weeks post-infection. Yet, this cytokine does not directly act on the bacteria nor does it function to recruit the granulocytes that are needed to eliminate the pathogen. Instead, IL-23:
A) Functions as a chemoattractant for eosinophils and basophils
B) Stimulates IL-17 and IL-22 production by ILC3 cells
C) Activates tissue-resident ILC2 cells to produce IL-5 and IL-13
D) Induces the differentiation of naive CD8 T cells into cytotoxic T cells
E) Stimulates gastrointestinal epithelial cells to produce antimicrobial peptides

Question

Quizplus · Accepted Answer

IL-23 stimulates the production of IL-17 and IL-22 by ILC3 cells, which play a critical role in protective immune responses against extracellular bacterial and fungal infections. These cytokines promote neutrophil recruitment and production of antimicrobial peptides to eliminate the pathogen.

IL-23 Is a Cytokine Made by Macrophages and Dendritic Cells