Functional relevance of the IL-23-IL-17 axis in lungs in vivo

Abstract

It is known that interleukin (IL)-23, an IL-12-family cytokine, can be released by certain antigen-presenting cells in response to bacterial pathogens. Recent in vitro studies indicate that this cytokine stimulates a unique subset of CD4 cells, the T helper cell (Th)17 subset, to produce and release the proinflammatory cytokine IL-17. However, it has not been known whether this is an action of IL-23 per se that has bearing for the early innate response in lungs in vivo and whether there is an IL-23-responsive population of IL-17-producing CD4 cells in the bronchoalveolar space. We now present evidence that IL-23 can be involved in the early innate response to both gram-negative and gram-posi..