FIG. 4.
Effect of in vivo neutralization of IL-12 or IFN-γ on
trypanosomicidal activity of treatment with a suboptimal dose of Bz
during acute phase of infection with different strains of T.
cruzi. Swiss-Webster mice were infected with 5,000 trypomastigotes
of T. cruzi CL, Y, or Colombiana and were treated with Bz at
25 mg/kg/day for 7 days. Different groups of animals receiving drug
alone (○, white bars) were simultaneously injected with either an
anti-IFN-γ MAb
(
, gray
bars) or an anti-IL-12 MAb (▵, dotted bars) 1 day prior to infection
and once a week afterward. The levels of parasitemia (left panels) and
the rates of mortality (right panels) were monitored daily until the
end of the experiment. Infected and nontreated animals were used as
controls (■, black bars). For each datum point presented in the
parasitemia curve the average and positive standard deviation are shown
for three to five animals per group. Similar numbers of animals were
used for the mortality study. This experiment was repeated once and
yielded identical results. Note that the scale indicating the level of
parasitemia (left panels) is different for each T. cruzi
strain.