Interleukin-6 (IL-6) prevents activation-induced cell death: IL-2-independent inhibition of Fas/fasL expression and cell death

Blood. 1998 Dec 1;92(11):4212-9.

Abstract

Triggering of the TCR/CD3 complex with specific antigen or anti-CD3 monoclonal antibody initiates activation-induced cell death (AICD) in mature T cells, an effect also mediated by the Fas/FasL system. We have previously shown that CD2 stimulation rescues T cells from TCR/CD3-induced apoptosis by decreasing the expression of Fas and FasL. In the present study, we examined whether the endogenous production of IL-2 plays a role in the effects mediated by CD2 triggering. The results indicated that transcription of Fas/FasL is controlled by interleukin-2 (IL-2) production and that CD2 triggering rescues a T-cell hybridoma from AICD via decreased production of IL-2. To ascertain whether modulation of IL-2 may be a general mechanism of AICD control, we examined other stimuli, capable of modulating the expression of the Fas/FasL system and the ensuing AICD, for ability to affect production of IL-2. We found that IL-6 reduced the level of TCR/CD3-induced apoptosis and the expression of Fas/FasL, yet failed to inhibit IL-2 production. Because IL-2 is involved in both apoptosis and activation events, these results indicate that, in contrast to CD2, which inhibits apoptosis and T cell activation, IL-6 inhibits apoptosis but not IL-2-induced activation. These observations may provide the basis for differential control of T-cell activation and apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / pharmacology
  • Apoptosis / drug effects
  • Apoptosis / immunology*
  • Cricetinae
  • Down-Regulation
  • Fas Ligand Protein
  • Interleukin-2 / immunology*
  • Interleukin-6 / immunology*
  • Lymphocyte Activation / drug effects
  • Lymphocyte Activation / immunology
  • Membrane Glycoproteins / immunology*
  • Mice
  • Mice, Inbred C3H
  • T-Lymphocytes / immunology
  • T-Lymphocytes / pathology*
  • fas Receptor / immunology*

Substances

  • Antibodies, Monoclonal
  • Fas Ligand Protein
  • Fasl protein, mouse
  • Interleukin-2
  • Interleukin-6
  • Membrane Glycoproteins
  • fas Receptor