Human TNF-α inhibits the pre-erythrocytic stage of Pyy265BY.

<p>A. HepG2/CD81 hepatoma cell cultures were treated with various concentrations of recombinant human TNF-α, 48 h prior to, at the time of, and then 3 h and 24 h after sporozoite inoculation. Cultures were stopped 45 h after infection. Data are presented as the mean (± SD) reduction in Pyy265 liver schizonts numbers and represent data from two independent experiments (one represented by filled circles and the other by open circles). Parasite number reduction was calculated by enumerating 48 h liver schizonts in triplicate cultures exposed or not to TNF-α. Data are presented as the mean (± SD) reduction in liver schizont numbers in triplicate wells compared to the mean number in 6 control wells. The number of liver schizonts in control wells was 67±9.9. B. Timing of the antiparasitic effect of human TNF-α. HepG2/CD81 cells were incubated with 100 ng/ml of human TNF-α for different times. Cultures were stopped 48 h after sporozoite inoculation. Data are presented as the mean (± SD) numbers of liver schizonts in triplicate experimental wells and in six control wells. * <i>p</i><0.05 versus control non-treated cultures (Kruskal-Wallis test, followed by Dunn test). The rate of infection Pyy265 sporozoites for HepG2/CD81 hepatoma cell was between 0.5 to 2% depending on the experiment. Data are representative of three independent experiments with similar results.