Distinct Effects of T-bet in T _H 1 Lineage Commitment and IFN-γ Production in CD4 and CD8 T Cells

TLDR

T‑bet, a T‑box transcription factor, drives TH1 lineage commitment by inducing interferon‑γ, a cytokine also produced by NK and CD8 cells that is essential for microbial defense. The study shows that T‑bet is necessary for interferon‑γ production in CD4 and NK cells but dispensable in CD8 cells, revealing distinct transcriptional controls of this cytokine across T‑cell lineages.

Abstract

T-bet is a member of the T-box family of transcription factors that appears to regulate lineage commitment in CD4 T helper (T H ) lymphocytes in part by activating the hallmark T H 1 cytokine, interferon-γ (IFN-γ). IFN-γ is also produced by natural killer (NK) cells and most prominently by CD8 cytotoxic T cells, and is vital for the control of microbial pathogens. Although T-bet is expressed in all these cell types, it is required for control of IFN-γ production in CD4 and NK cells, but not in CD8 cells. This difference is also apparent in the function of these cell subsets. Thus, the regulation of a single cytokine, IFN-γ, is controlled by distinct transcriptional mechanisms within the T cell lineage.