We report here that the expression of the transcription factor T-bet, which is known to be required for effector cytotoxic CD8+ T lymphocytes (CTL) generation and effector memory cell formation, is regulated in CTL by microRNA-155 (miR-155). Importantly, we show that the proliferative effect of miR-155 on CD8+ T cells is mediated by T-bet. T-bet levels in CTL were controlled in vivo by miR-155 via SH2 (Src homology 2)-containing inositol phosphatase-1 (SHIP-1), a known direct target of miR-155, and SHIP-1 directly downregulated T-bet. Our studies reveal an important and unexpected signaling axis between miR-155, T-bet, and SHIP-1 in in vivo CTL responses and suggest an important signaling module that regulates effector CTL immunity.

, , , , ,
doi.org/10.3389/fimmu.2017.01696, hdl.handle.net/1765/103438
Frontiers in Immunology
Erasmus MC: University Medical Center Rotterdam

Hope, J., Stairiker, C. J., Spantidea, P.I. (Panagiota I.), Gracias, D. T., Carey, A.J. (Alison J.), Fike, A. J., … Katsikis, P. (2017). The transcription factor T-Bet is regulated by MicroRNA-155 in murine anti-viral CD8+ T cells via SHIP-1. Frontiers in Immunology, 8(DEC). doi:10.3389/fimmu.2017.01696