Priming effect of interferons and interleukin 2 on endogenous production of tumor necrosis factor in mice.

The effects of interferons (IFNs) and interleukin 2 (IL 2) on endogenous production of tumor necrosis factor (TNF) were investigated in mice. Production of serum TNF was triggered by iv injection of OK-432 and tested by in vitro cytotoxicity assay. Injection of recombinant IFN-gamma with OK-432 and tested by in vitro cytotoxicity assay. Injection of recombinant IFN-gamma with OK-432 or of IFN-alpha/beta, recombinant IFN-beta, recombinant IFN-alpha A/D or recombinant IL 2 six hours before OK-432 enhanced TNF production about 10-fold, which indicated priming actions of these compounds in TNF production. These findings suggest that these compounds could also be used as priming agents for endogenous production of TNF in cancer patients.