FIG. 3.

Effects of splenocyte supernatants (SN) of immunized mice on intracellular parasite growth in peritoneal macrophages in the absence (A) and presence of anticytokine antibodies (Ab) (B) or TGF-β (C). Peritoneal macrophages harvested from naive mice were pretreated for 12 to 18 h with supernatants from s.c. immunized mice either alone or in the presence of 10 μg/ml of each of the anticytokine antibodies and appropriate isotype-matched control antibodies. IFN-γ at 10 ng/ml was used as a positive control. Again, macrophages were pretreated with supernatants from i.p. immunized mice alone or with various concentrations of TGF-β ranging from 0.5 to 100 ng/ml. After 3 h of infection, unphagocytosed parasites were removed by washing with PBS and cultured in the same medium with supernatants, IFN-γ, antibodies, or TGF-β, using similar concentrations. Seventy-two hours later, the number of intracellular amastigotes was determined. Results are means ± SE for five experiments done in triplicate. **, P < 0.001 for comparison to control groups.