An Indispensable Role for STAT1 in IL-27-Induced T-bet Expression but Not Proliferation of Naive CD4 + T Cells

摘要: IL-27 is a novel IL-12 family member that plays role in the early regulation of Th1 initiation, induces proliferation naive CD4 + T cells, and synergizes with IFN-γ production. It has been recently reported T-bet IL-12Rβ2 expression through JAK1/STAT1 activation. In present study, we further investigated JAK/STAT signaling molecules activated by also STAT1 IL-27-mediated responses using STAT1-deficient mice. addition to JAK1 STAT1, IL-27-activated JAK2, tyrosine kinase-2, STAT2, -3, -5 cells. The activation STAT2 STAT5, but not STAT3, was greatly diminished Comparable proliferative response observed between wild-type contrast, hardly induced subsequent expression, synergistic production impaired Moreover, augmented MHC class I on cells STAT1-dependent manner. These results suggest activates -2, an indispensable IL-27-induced as well proliferation, while STAT3 presumably important proliferation.