FIG. 2.

Kinetics of CD4⁺ CD25⁺ T-cell frequencies and body weight during acute infection with Brazil strain T. cruzi in mice untreated or treated with anti-CD25 MAbs. 2 days prior to infection, and on the day of infection, 2 groups of mice were i.p. injected with 400 μg anti-CD25 depleting MAb (PC61 clone). As a control, another group of mice was left untreated. These 3 groups of mice were then inoculated i.p. with 1 × 10³ Brazil strain tissue culture trypomastigotes. Additionally, 400 μg anti-CD25 MAb injections were continuously administered to one group of previously treated mice (deplete-infect-deplete, filled triangles, n = 7) on days 7, 11, 14, 19, 24, and 29 post infection. After the day of infection, neither treated mice (deplete-infect, filled squares, n = 7) nor untreated mice (infect only, filled circles, n = 7) received subsequent anti-CD25 MAb injections. As an additional control, one group of age-matched mice remained untreated and uninfected (“naïve,” open circles, n = 3). (A) Frequencies of circulating CD4⁺ CD25⁺ T cells on days indicated. PBLs were stained with CD4-PE and CD25 (7D4 clone)-FITC, and analyzed on a Cyan (Dako Cytomation) flow cytometer. (B) Body weights were measured on days indicated. For both graphs, error bars represent standard deviation.