With(out) a little help from my friends: an IL-12/CD40L-mediated feed-forward loop between CD8+ T cells and DCs

Eur J Immunol. 2013 Jun;43(6):1445-8. doi: 10.1002/eji.201343644.

Abstract

CD40-CD40L interactions are important for both antigen-dependent B-cell differentiation and effector and memory T-cell formation. The prevailing view is that CD40L is expressed on activated CD4(+) T cells, which enables them to provide help to high-affinity B cells in GCs and to license DCs for efficient induction of CD8(+) T-cell responses. Interestingly, CD8(+) T cells themselves can also express CD40L and, in this issue of the European Journal of Immunology, Thiel and colleagues [Eur. J. Immunol. 2013. 43: 1511-1517] show that CD40L expression on these cells can be part of a self-sustaining feed-forward loop, in which expression of CD40L is induced by IL-12 and TCR signaling. This provides a paradigm shift in our thinking about the requirements of effector CD8(+) T-cell development and the role herein of CD4(+) T cells to provide help in this process.

Publication types

  • Research Support, Non-U.S. Gov't
  • Comment

MeSH terms

  • Animals
  • CD40 Ligand / metabolism*
  • CD8-Positive T-Lymphocytes / immunology*
  • Humans
  • Interleukin-12 / immunology*
  • Receptors, Antigen, T-Cell / metabolism*
  • T-Lymphocytes, Helper-Inducer / immunology*

Substances

  • Receptors, Antigen, T-Cell
  • CD40 Ligand
  • Interleukin-12