TOXIC SHOCK SYNDROME TOXIN-1 ENHANCES SYNTHESIS OF ENDOTOXIN-INDUCED TUMOR-NECROSIS-FACTOR IN MICE

Toxic shock syndrome toxin 1 (TSST-1) was tested for its ability to enhance the production of endotoxin-induced tumor necrosis factor (TNF) in C3H/HeN mice. The TNF level in serum was quantified by a sandwich enzyme-linked immunosorbent assay (ELISA). It was found that when mice were injected with 20-mu-g of TSST-1 12 h before exposure to 1-mu-g of endotoxin, the serum endotoxin-induced TNF was 20 times as high as that found in mice exposed to endotoxin alone. Although 20-mu-g of TSST-1 did induce a maximum level of near 1 ng of TNF per ml of serum 1.5 h after exposure, the TNF concentration was greatly diminished after 5 to 6 h and was no longer detectable after 12 h. Pretreatment of mice with 20-mu-g of TSST-1 or 1-mu-g of endotoxin did not influence TNF induction by TSST-1 12 h later. Also, pretreatment of mice with 1-mu-g of endotoxin did not enhance TNF induction by endotoxin 12 h later. Enhancement was achieved only when mice were exposed to TSST-1 more than 4 h and less than 24 h before injection of endotoxin. Despite the relatively high serum TNF levels (30 to 50 ng/ml), no mortality was observed in the mice treated with both TSST and endotoxin.