Induction by toxic-shock-syndrome toxin-1 of a circulating tumor necrosis factor-like substance in rabbits and of immunoreactive tumor necrosis factor and interleukin-1 from human mononuclear cells.

A shock-like syndrome was induced in rabbits by administering toxic-shock-syndrome toxin-1 (TSST-1); tumor necrosis factor (TNF)-like activity was detected in sera of rabbits 3.5 h after injection, as measured by cytotoxic effects on the tumorigenic L929 murine fibroblast cell line. Appearance of this activity in sera coincided with onset of significant shock-related hemodynamic changes. TSST-1 stimulated release of TNF-like material from rabbit mononuclear cells in culture. Human mononuclear cells also secreted a cytotoxic substance shown to be TNF by radioimmunoassay. Maximal TNF secretion was higher in human mononuclear cells stimulated with TSST-1 than in those stimulated with bacterial lipopolysaccharide. Lipopolysaccharide, however, was a more potent inducer of interleukin-1 alpha and interleukin-1 beta from the same cells than was TSST-1. Because TNF and interleukin-1 act synergistically during induction of a shock-like state, these results suggest that part of the TSST-1-induced shock is due to production of interleukin-1 and TNF.