[PDF][PDF] The transcriptional repressor Bcl-6 directs T follicular helper cell lineage commitment

D Yu, S Rao, LM Tsai, SK Lee, Y He, EL Sutcliffe… - Immunity, 2009 - cell.com
D Yu, S Rao, LM Tsai, SK Lee, Y He, EL Sutcliffe, M Srivastava, M Linterman, L Zheng…
Immunity, 2009cell.com
Follicular helper T (Tfh) cells provide selection signals to germinal center B cells, which is
essential for long-lived antibody responses. High CXCR5 and low CCR7 expression
facilitates their homing to B cell follicles and distinguishes them from T helper 1 (Th1), Th2,
and Th17 cells. Here, we showed that Bcl-6 directs Tfh cell differentiation: Bcl-6-deficient T
cells failed to develop into Tfh cells and could not sustain germinal center responses,
whereas forced expression of Bcl-6 in CD4+ T cells promoted expression of the hallmark Tfh …
Summary
Follicular helper T (Tfh) cells provide selection signals to germinal center B cells, which is essential for long-lived antibody responses. High CXCR5 and low CCR7 expression facilitates their homing to B cell follicles and distinguishes them from T helper 1 (Th1), Th2, and Th17 cells. Here, we showed that Bcl-6 directs Tfh cell differentiation: Bcl-6-deficient T cells failed to develop into Tfh cells and could not sustain germinal center responses, whereas forced expression of Bcl-6 in CD4+ T cells promoted expression of the hallmark Tfh cell molecules CXCR5, CXCR4, and PD-1. Bcl-6 bound to the promoters of the Th1 and Th17 cell transcriptional regulators T-bet and RORγt and repressed IFN-γ and IL-17 production. Bcl-6 also repressed expression of many microRNAs (miRNAs) predicted to control the Tfh cell signature, including miR-17-92, which repressed CXCR5 expression. Thus, Bcl-6 positively directs Tfh cell differentiation, through combined repression of miRNAs and transcription factors.
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