Cytokine production in DBA/2 mice treated with IL-2 and infected with P. yoelii (17XL strain). Mice (n = 3) were either given IL-2 treatment only or treated with IL-2 and given infection with P. yoelii. Spleen cells were harvested from mice infected for 3 or 6 days and enriched for T cells by passage on nylon-wool column and bulk cultures were set up with 2 × 10 6 cells/well. Cells were stimulated for 48 hours with cross-linked anti-CD3 mAb and the cytokine production in culture supernatants was assessed. The production of IFN-γ, IL-10, and TNF-α by normal mouse cells stimulated with cross-linked anti-CD3 mAb was 966 ± 321 pg/ml, 1,500 ± 102 pg/ml, and 456 ± 58 pg/ml, respectively. The production of IFN-γ, TNF-α, or IL-10 in the absence of stimulation (ie, medium alone) in culture supernatants of cells from treated or untreated mice with or without infection was <200 pg/ml.