Regulation of Defense Responses against Protozoan Infection by Interleukin-27 and Related Cytokines

[摘要] Cytokine-mediated immunity is crucial in the defense against pathogens.Recently, IL-23 and IL-27 were identified, which along with IL-12 belong tothe IL-12 cytokine family. IL-27 is pivotal for the induction of helper Tcell (Th) 1 responses while IL-23 is important for the proliferation ofmemory type Th1 cells. Recent studies revealed that IL-27 also has ananti-inflammatory property. In some protozoan infection, variousproinflammatory cytokines were over produced causing lethal inflammatoryresponses in IL-27 receptor-deficient mice. The anti-inflammatory effect ofIL-27 depends, at least partly, on inhibition of the development of Th17cells, a newly identified Th population that is induced by IL-23 and ischaracterized by the production of the inflammatogenic cytokine, IL-17.IL-27 thus has a double identity as an initiator and as an attenuator ofimmune responses and inflammation. With the discoveries of the newIL-12-related cytokines and Th17 cells, Th development is facing a newparadigm.

[学科分类] 基础医学