Regulation of interleukin-10 and interleukin-22 expression in T helper cells

Interleukin (IL)-10 and IL-22 are crucial regulators of inflammation during immune responses. While IL-10 functions to prevent excessive inflammation by acting on immune cells, IL-22 elicits innate responses from tissue epithelia and promotes wound healing. Although T helper (Th) cells are a major source for both cytokines, IL-10 and IL-22 are rarely co-expressed at high levels in the same cells. Here we discuss a number of common aspects as well as crucial differences in the molecular regulation of both cytokines that might explain their broad, but distinct expression among Th cell subsets.

► IL-10 and IL-22 are broadly expressed among Th cells.
► The regulation of IL-10 and IL-22 expression is largely independent of a particular T cell differentiation program
► IL-10 and IL-22 are rarely co-expressed in high levels by the same T cell.
► IL-10 and IL-22 share a common positive regulation by STAT3, AhR, and the Notch pathway.
► TGF-β, IL-27 and ICOS have contrasting effects on IL-10 and IL-22 expression.