Figure 2.

Ara-LAM treatment inhibited the suppressive activity of T regulatory cells during VL. (A) CD4⁺CD25⁻ T cells and CD4⁺CD25⁺ T cells were purified from spleen of differently treated mice (section ‘Materials and methods’) after 28 days post-infection. CD4⁺CD25⁻ responder T cells (5 × 10⁵ cells) and T-depleted, mitomycin C-treated, syngeneic APCs (5 × 10⁵ cells) were stimulated with SLA in the absence or presence of increasing numbers of splenic CD4⁺CD25⁺ Treg cells for 4 days. Proliferation was measured by an 18 h [3H]thymidine incorporation assay. Data represent means ± SD for three animals per group. *P < 0.001 for the comparison with infected mice. (B and C) The supernatants were collected at 24 h for IL-2 (B) or 72 h for IFN-γ (C) following stimulation with SLA, and level of cytokines was determined by ELISA. Data represent means ± SD for triplicate sets. *P < 0.001 for the comparison with infected mice.