Protection of rats against Schistosoma mansoni infection induced by platelets stimulated with the murine recombinant tumor necrosis factor alpha.

Human recombinant tumor necrosis factor (rTNF alpha) and lymphotoxin (rTNF beta) have been shown to enhance the schistosomicidal activity of human platelets in vitro. In this report, we demonstrated that the murine rTNF was able to induce the in vitro cytotoxic activity of both murine and rat platelets towards the larvae of Schistosoma mansoni, whereas human rTNFs activated only the murine platelets. Passive transfer of platelets stimulated with murine rTNF significantly protected rats up to a 65% reduction of the worm burden. Thus, rTNF may constitute, via its interactions with effector cells, an important regulatory mechanism during the parasitic infection of rats.