Greater differentiation of Th17 in PARP-1^−/−T cells in vitro. (A) Scatterplot (left) of staining of IL-17 vs IFNγ on sorted CD4⁺ T cells from PARP-1^−/− or PARP-1^+/+ littermate controls stimulated with anti-CD3 (0.5 µg/mL) antibody and PARP-1^+/+ APCs in the absence (Med) or presence of TGF-β1 plus IL6 (TGFβ1+IL6) for 4 days. Data are representative of 2 independent experiments. The histogram (right) is summarized analysis of 2 experiments. *P < .05 (unpaired 1-tailed Student t test). (B) IL-17 levels in supernatants from cultures described in panel A (mean ± SEM of duplicate measurements). (C) Quantitative PCR analysis of Rorc expression in CD4⁺CD25⁻ T cells from PARP-1^−/− or PARP-1^+/+ littermate controls stimulated with an anti-CD3 (0.5 µg/mL) antibody and PARP-1^+/+ APCs in the absence (Med) or presence of TGF-β1 plus IL6 (TGFβ-1+IL6) for 2 days (mean ± SEM of duplicate measurements). (D) Staining of RORγt in CD4⁺T cells from PARP-1^−/− or age-matched PARP-1^+/+ control littermates which were stimulated with anti-CD3 (0.5 µg/mL) antibody and PARP-1^+/+ APCs in the absence (Med) or presence of TGF-β1 and IL6 (TGFβ1+IL6) for 4 days. *P < .05; **P < .01 (unpaired 2-tailed Student t test).