Fig. 1

Standard immunosuppressive therapy in solid organ transplantation has limited efficacy in mouse skin transplantation, even in MHC-matched situations. (A) Schematic overview of auto or allogeneic skin transplantation. (B) TDC-based immunoregulation protocol. Immunosuppression was performed by using a protocol of administrating a combination of methylprednisolone, tacrolimus, and mycophenolate mofetil daily (TDC) with or without anti-CD4 mAb and anti-CD8mAb on day 6 and 1 (TDC mAb). (C) Skin graft survival under immunosuppression with TDC (n = 9, C3129F1; n = 9, BALB/c; n = 9, C57BL/6; n = 9, CBA/N). (D) Skin graft survival under immunosuppression with TDC + mAb (n = 10, C3129F1; n = 11, BALB/c; n = 10, C57BL/6; n = 9, CBA/N). (E) Macroscopic observation (upper panels) and hematoxylin and eosin stained section (lower panels) of autologous (C3129F1) and CBA/N skin grafts on day 100. Scale bars: 100 μm. (F) Immunohistochemical staining for CD3 of CBA/N skin grafts harvested from TDC or TDC + mAb treated groups on 100 days post-transplantation. Upper and lower panels represent CD3 specific staining and isotype control stained section, respectively. Scale bars: 100 μm. (G) Recipient T cell response in MHC-matched but minor antigen-mismatched skin transplantation. The T cell proliferation rates in each treatment group were normalized to that of C3129F1 mice stimulated with autologous irradiated splenocytes. Error bars indicate standard error of technical triplicates. Similar results were obtained in two independent experiments. *p < 0.05, **p < 0.01 (Tukey’s HSD test). (H) De novo anti-donor antibody production in the recipients. Error bars indicate standard error of biological replicates (n = 8, naive; n = 4-5, non-treatment; n = 9, TDC; n = 7, TDC + mAb). tx, transplantation; mAb, monoclonal antibody; TDC, three drug combination; POD, post-operative day