Application of CD4+ CD25+ T regulatory cells in trachea allograft transplant model of mice to reject anti-graft response

To study the role of CD4⁺ CD25⁺ Treg cells in anti-graft rejection response and potential value in application of lung transplatation, we established mice trachea allograft transplant model and sort CD4⁺ CD25⁺ Treg cells from mice spleen lymphocytes by MACS. FCM assays were done to analyze the ratio of marker protein, Foxp3, expression in CD4⁺ CD25⁺ Treg cells. Alveolar cells were used as a non-specific antigen to activate iDCs into mDCs, and cocultureed with CD4⁺ CD25⁺ Treg cells to activate Treg cells. The activated Treg cells were inject into mice with trachea allograft transplantation to reduce rejection response. The allografts were extracted and done pathological examination with H&E staining. The purity of CD4⁺ CD25⁺ Treg cells were over 80% and specifically express Foxp3, the organizational structure of implanted trachea showed that the tracheal structure was intact. Our research imply that CD4⁺ CD25⁺ Treg cells play an essential role in reducing rejection, and lay the foundation for reject anti-graft response in clinical application.