[Activation of the production of the tumor-necrosis factor by the combined action of lipopolysaccharide and muramyl dipeptide in vitro and in vivo].

The effect of bacterial lipopolysaccharide (LPS), muramyl dipeptide (MDP) and their combination on the production of tumour necrosis factor by spleen cells in vitro and on tumour regression in vivo has been studied. TNF activity was detected in spleen cell supernatants and serum of mice treated with drugs, using L929 cells as targets. The combination of LPS and MDP was more effective in TNF production than each of the drugs used alone in vitro and in vivo. The injection of LPS and MDP to A/Sn mice with subcutaneous nodes of sarcoma SA-I resulted in total tumour necrosis. The treatment of mice with these drugs in water solutions was more effective, however, more toxic than the administration of LPS-treated splenocytes in MDP solution.