TCR signaling via Tec kinase ITK and interferon regulatory factor 4 (IRF4) regulates CD8+ T-cell differentiation.

Journal Article (Journal Article)

CD8(+) T-cell development in the thymus generates a predominant population of conventional naive cells, along with minor populations of "innate" T cells that resemble memory cells. Recent studies analyzing a variety of KO or knock-in mice have indicated that impairments in the T-cell receptor (TCR) signaling pathway produce increased numbers of innate CD8(+) T cells, characterized by their high expression of CD44, CD122, CXCR3, and the transcription factor, Eomesodermin (Eomes). One component of this altered development is a non-CD8(+) T cell-intrinsic role for IL-4. To determine whether reduced TCR signaling within the CD8(+) T cells might also contribute to this pathway, we investigated the role of the transcription factor, IFN regulatory factor 4 (IRF4). IRF4 is up-regulated following TCR stimulation in WT T cells; further, this up-regulation is impaired in T cells treated with a small-molecule inhibitor of the Tec family tyrosine kinase, IL-2 inducible T-cell kinase (ITK). In contrast to WT cells, activation of IRF4-deficient CD8(+) T cells leads to rapid and robust expression of Eomes, which is further enhanced by IL-4 stimulation. In addition, inhibition of ITK together with IL-4 increases Eomeso up-regulation. These data indicate that ITK signaling promotes IRF4 up-regulation following CD8(+) T-cell activation and that this signaling pathway normally suppresses Eomes expression, thereby regulating the differentiation pathway of CD8(+) T cells.

Full Text

Duke Authors

Cited Authors

  • Nayar, R; Enos, M; Prince, A; Shin, H; Hemmers, S; Jiang, J-K; Klein, U; Thomas, CJ; Berg, LJ

Published Date

  • October 9, 2012

Published In

Volume / Issue

  • 109 / 41

Start / End Page

  • E2794 - E2802

PubMed ID

  • 23011795

Pubmed Central ID

  • PMC3478592

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

Digital Object Identifier (DOI)

  • 10.1073/pnas.1205742109


  • eng

Conference Location

  • United States