Human TNF-α inhibits the pre-erythrocytic stage of P. falciparum.
Primary human hepatocyte cell cultures were treated with various concentrations of recombinant human TNF-α, 24 h (A) or 48 h (B) before, at the time of sporozoite inoculation, and then every day for day 1 to day 5. Cultures were stopped 5 days later after sporozoite inoculation. The data presented are mean numbers (± SD) of 5 days P. falciparum liver stages from triplicate experimental wells and from 8 control wells. * p<0.05 versus control non-treated cultures (Kruskal-Wallis test, followed by Dunn test). The rate of infection for P. falciparum sporozoites was 0.2–0.5% for primary human hepatocytes depending on the experiment. Data are representative of two independent experiments with similar results.