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 coexpressed 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.