Additional Tregs in the graft reduces T-cell–produced proinflammatory cytokines but does not lead to a better clinical outcome. (A) Arthritis scores after transplantation. Arthritis scores were set to 100% on the day of transplantation, and the subsequent clinical effect was expressed as a percentage of the score at the time of transplantation. Mean arthritis scores are shown (±SEM error bars). Data are representative of 2 individually performed experiments. (B) Area under the arthritis score curve during the 7-week follow-up period. Mean area under the curve ± SEM error bars are shown. PGIA (black bar), N = 4; PGIA+BMT (white bar), N = 4; PGIA+BMT+250,000 Tregs (gray bar), N = 5; and PGIA+BMT+500,000 Tregs (dark gray bar), N = 5. *P < .05 compared to PGIA control group (Mann-Whitney U test). (C) Spleen cells were isolated 7 weeks after BMT and cultured in culture medium with the addition of anti-CD3 (1 μg/mL) for 96 hours. Supernatants were collected and analyzed with Multiplex Immuno Assay for interferon-γ (IFNγ), IL-17, IL-10, and tumor necrosis factor-α (TNFα) production. PGIA, N = 4; PGIA+BMT, N = 4; PGIA+BMT+250,000 Tregs, N = 5; and PGIA+BMT+500,000 Tregs, N = 5. *P < .05 compared with PGIA+BMT (Mann-Whitney U test).