Figure 4.

Expression of antibodies and cytokines is upregulated in pfp^−/− and C57BL/6 mice during Trypanosoma cruzi infection. (a) Profile of antibody levels in serum of infected C57BL/6 and pfp^−/− mice. Anti-T. cruzi lysate immunoglobulin (Ig)G1, IgG2c and IgG3 isotypes were determined in the serum during the acute and chronic phases of infection. The graphs show means of at least five animals per group. The data are representative of two independent experiments. The gray area represents the mean plus twofold SD of non-infected mice for each IgG isotype. *P< 0.05 or **P< 0.01 for comparison of pfp^−/− (white circle) vs. C57BL/6 (black circle) infected mice at the same time point. (b) Splenocytes from non-infected (triangles) or T. cruzi-infected (circles) C57BL/6 (black) and pfp^−/− (white) mice were incubated in vitro with Brefeldin A. After 4 h of incubation, the cells were harvested and cytokine production was evaluated by intracellular staining. Averages of 3–6 mice per group are presented in total lymphocytes (R1 gate) that produce interferon-γ, interleukins 4 and 10. The data represent one out of two-three experiments. Non-infected vs. infected, *P< 0.05 or **P< 0.01; infected vs. infected, ^#P< 0.05; non-infected vs. non-infected, ^$P< 0.05.