Adoptive transfer of Treg cells improves the protective effect of CD4+Foxp3- T cells.

(A) Survival curves of Rag1-/- mice infected with Pb18 after adoptive transfer of 2×105 Treg cells, 2×106 CD4+Foxp3- T cells, 2×105 Treg cells + 2×106 CD4+Foxp3- T cells, or vehicle only (p < 0.05 between PBS and Treg; p < 0.001 between PBS and CD4+Foxp3- T cells; p <0.001 between PBS and CD4+Foxp3- + Treg; p < 0.05 between Treg and CD4+Foxp3-; p < 0.001 between Treg and CD4+Foxp3- + Treg; n ≥ 13). (B and C) Analysis of disease severity through recovery of CFU from lungs, livers and spleens from Rag1-/- mice infected with Pb18 after adoptive transfer of 2×105 Treg cells, 2×106 CD4+Foxp3- T cells, 2×105 Treg cells + 2×106 CD4+Foxp3- T cells, or vehicle only. Horizontal bars indicate the mean value in each group (* = p < 0.05; ** = p < 0.005; *** = p < 0.001; n ≥ 10).