Human recombinant tumor necrosis factor alpha protects susceptible A/J mice against lethal Plasmodium chabaudi AS infection.

The effect of intravenous treatment with human recombinant tumor necrosis factor alpha (rTNF-alpha) on infection of susceptible A/J and resistant C57BL/6 mice with Plasmodium chabaudi AS was examined. Treatment of A/J mice with 10(3) or 10(5) U of rTNF-alpha on days 0, 3, 5, 7, and 9 after intraperitoneal infection with 10(6) parasitized erythrocytes resulted in 80% survival and a significant decrease in the peak parasitemia level. Treatment of susceptible A/J hosts with 10(5) but not 10(3) U of rTNF-alpha resulted in increased survival but did not alter the peak parasitemia level following infection with 10(7) parasitized erythrocytes. Moreover, all surviving A/J mice completely eliminated the parasite by approximately 4 weeks and were fully protected against a secondary infection. Except at a dose of 5 x 10(5) U of rTNF-alpha, which resulted in 100% mortality of infected animals, rTNF-alpha did not alter the course or outcome of infection with P. chabaudi AS in resistant C57BL/6 mice.