Activation of human vascular endothelial cells by IFN-gamma: acquisition of HLA class II expression, TSST-1-binding activity and accessory activity in T cell activation by the toxin

Int Arch Allergy Appl Immunol. 1991;96(1):55-61. doi: 10.1159/000235535.


Human umbilical vascular endothelial cells (HUVEC) stimulated with recombinant human IFN-gamma were investigated for expression of HLA class II molecules, toxic shock syndrome toxin-1 (TSST-1)-binding activity and accessory cell (AC) activity in TSST-1-induced T cell activation. HUVEC stimulated with recombinant human IFN-gamma ranging from 10 to 1,000 units/ml for 72 h express HLA class II molecules. Intensity of the expression was dependent on the concentration of IFN-gamma. HUVEC stimulated with 1,000 units/ml of IFN-gamma for 72 h exhibited 125I-TSST-1-binding that was blocked by the unlabeled toxin and monoclonal antibodies (mAb) to DR/DP. The activity was not removed by paraformaldehyde fixation. The IFN-gamma-stimulated HUVEC exhibited AC activity in TSST-1-induced IL-2 production by T cells from human peripheral blood mononuclear cells. The activity was blocked by mAb to DR. The above two activities were also observed in L cells transfected with DR2 genes but not in the unstimulated HUVEC and control L cells. In view of the fact that TSST-1 binds directly to HLA class II molecules and activates human T cells in association with HLA class II molecules on AC, it is likely that the acquisition of TSST-1-binding activity and AC activity in the toxin-induced T cell activation is mediated by the expression of HLA class II molecules. Vascular endothelial cells may play an important role in the development of pathological changes in TSS patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Antigen-Presenting Cells / immunology
  • Bacterial Toxins*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / immunology*
  • Enterotoxins / immunology*
  • Flow Cytometry
  • HLA-D Antigens / immunology*
  • Humans
  • Interferon-gamma / immunology
  • Lymphocyte Activation / immunology
  • Recombinant Proteins
  • Staphylococcus aureus
  • Superantigens*
  • T-Lymphocytes / immunology*
  • Umbilical Cord / blood supply


  • Antibodies, Monoclonal
  • Bacterial Toxins
  • Enterotoxins
  • HLA-D Antigens
  • Recombinant Proteins
  • Superantigens
  • enterotoxin F, Staphylococcal
  • Interferon-gamma