Both oral PrA and infusion of PrA-treated Wistar DCs prolonged allograft survival and expanded alloantigen-specific Tregs.

<p>(A) SD rats were transplanted with Wistar cardiac allograft and received different treatment posttransplantation. Infusion of PrA-treated DCs or oral PrA promoted cardiac allograft survival. Mean survival time was significantly longer for the PrA-treated DC group (9.000±0.791 days, n = 10) and PrA group (9.000±0.483 days, n = 10) compared to the PBS-injected control group (6.000±0.362 days, n = 10). (B, C) At day 7 posttransplantation, CD4⁺CD25⁺populations were gated in recipient spleen lymphocytes and Foxp3 expression was observed by FACS. Both PrA and PrA-treated DC infusion expanded the CD4⁺CD25⁺Foxp3⁺ Treg population in spleen cells of recipient rats. (D, E) Both PrA treatment and PrA-treated DC infusion suppressed T cell proliferation in an alloantigen specific manner in recipient rats. On day 7, T cells isolated from SD recipient rats (responders) were mixed with donor Wistar spleen cells or third party DA spleen cells in MLRs and T cell proliferation assessed by Brdu incorporation. The results are means ± SE of three independent experiments (C–E; n = 3). Similar results were obtained in three independent experiments (B; n = 3). *P<0.05 compared to LPS-treated PrA-naïve control DCs.