PU.1 Regulates Expression of the Interleukin-7 Receptor in Lymphoid Progenitors

AbstractDevelopment of the lymphoid system is dependent on the Ets family transcription factor PU.1. We demonstrate that PU.1−/− hematopoietic progenitors fail to express IL-7Rα transcripts. Promoter and chromatin crosslinking analyses suggest that PU.1 directly regulates transcription of the IL-7Rα gene. Retroviral transduction of IL-7Rα into PU.1−/− progenitors restores IL-7-dependent proliferation and induces, at low frequency, the generation of pro-B cells undergoing an apparently normal program of differentiation. Although the related factor Spi-B can substitute for PU.1 in early B cell development, it is not required. These results demonstrate that PU.1 functions to regulate early B cell development in part by controlling the expression of the IL-7Rα gene