The transcription factor PU.1 is required for the development of IL-9-producing T cells and allergic inflammation

Abstract

CD4 + helper T cells acquire effector phenotypes that promote specialized inflammatory responses. We show that the ETS-family transcription factor PU.1 was required for the development of an interleukin 9 (IL-9)-secreting subset of helper T cells. Decreasing PU.1 expression either by conditional deletion in mouse T cells or the use of small interfering RNA in human T cells impaired IL-9 production, whereas ectopic PU.1 expression promoted IL-9 production. Mice with PU.1-deficient T cells developed normal T helper type 2 (TH 2) responses in vivo but showed attenuated allergic pulmonary inflammation that corresponded to lower expression of Il9 and chemokines in peripheral T cells and in lungs ..