CD4+ T cells reactivated with superantigen are both more sensitive to FasL-mediated killing and express a higher level of FasL

Cell Immunol. 1997 Aug 1;179(2):153-64. doi: 10.1006/cimm.1997.1159.


Naive CD4(+) T cells proliferate strongly in response to superantigens such as staphylococcal enterotoxin B (SEB). When these cells are rested and challenged a second time, they undergo activation-induced cell death (AICD). Fas/FasL interactions have been shown to mediate AICD, even though the level of Fas expression in the 2 degrees SEB responder populations is no higher than in the 1 degrees cultures. To determine whether the dissimilarity between the 1 degrees and 2 degrees cultures could be attributed to differences in FasL cytotoxic activity or in the sensitivity of the Fas apoptosis signaling pathway, we compared these parameters during the 1 degrees and 2 degrees responses of lpr and gld CD4+ T cells (which do not undergo AICD due to a lack of Fas and an inactive FasL, respectively) so that each parameter could be evaluated independently. The results demonstrate that 2 degrees responders both express a higher level of functional FasL and are more sensitive to FasL-mediated killing. These findings account for the differences between the 1 degrees and 2 degrees responses of CD4+ T cells to superantigen. In addition, we found that the apparent level of FasL-mediated cytotoxic activity in the 2 degrees lpr CD4+ T cell population is much higher than that of wild-type cells, suggesting that deficient Fas expression leads to inordinately high levels of FasL expression or subsaturation of FasL binding sites.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Surface / biosynthesis
  • Antigens, Surface / genetics
  • Antigens, Surface / physiology
  • Apoptosis / immunology
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / metabolism
  • Cytotoxicity, Immunologic*
  • Enterotoxins / immunology
  • Enterotoxins / pharmacology
  • Fas Ligand Protein
  • Kinetics
  • Ligands
  • Lymphocyte Activation*
  • Membrane Glycoproteins / biosynthesis*
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / toxicity*
  • Mice
  • Mice, Inbred MRL lpr
  • Protein Biosynthesis
  • RNA / biosynthesis
  • Staphylococcus aureus / immunology
  • Superantigens / immunology
  • Superantigens / pharmacology*
  • Time Factors
  • fas Receptor / biosynthesis*
  • fas Receptor / genetics
  • fas Receptor / toxicity*


  • Antigens, Surface
  • Enterotoxins
  • Fas Ligand Protein
  • Fasl protein, mouse
  • Ligands
  • Membrane Glycoproteins
  • Superantigens
  • fas Receptor
  • enterotoxin B, staphylococcal
  • RNA