FIG. 4.

Exposure to T. cruzi-infected monocytes induces a higher expression of inflammatory and anti-inflammatory cytokines by lymphocytes from chagasic patients. Percentages of cells positive for IL-10 (A), TNF-α (B), IFN-γ (C), and IL-4 (D) were determined within the lymphocyte gate, using PE-labeled monoclonal antibodies to each of the cytokines. Clear and black bars represent the average values obtained in nonstimulated cells or in cells exposed to parasite-infected monocytes, respectively. Results are expressed as averages ± standard errors. Identical numbers above the bars indicate statistical significance values using the Wilcoxon or Tukey-Kramer test, as described in Materials and Methods.