FIG. 3.

Effect of IL-10 and TGF-β on M. tuberculosis-stimulated CD4⁺ and γδ TCR⁺ T-cell proliferation. Positively selected CD4⁺ and γδ T cells (5 × 10⁴ cells/well) from M. tuberculosis-stimulated PBMC were cocultured with irradiated monocytes (10⁵ cells/well), M. tuberculosis (MTB) (10⁶ bacilli/well), and different concentrations of IL-10 or TGF-β. After 3 days, [³H]thymidine incorporation was measured and expressed as counts per minute. One representative experiment of four is shown. The standard error of the mean of triplicates did not exceed 10%. Both IL-10 and TGF-β inhibited CD4⁺ and γδ T-cell proliferation (n = 4; P, <0.05), but IL-10 was a more potent inhibitor than TGF-β for both CD4⁺ and γδ T cells.