The quantity and phenotype change of regulatory T cell in the model of mice liver transplantation

Objective To research immune graft rejection,the quantity and function of regulatory T cells in the model of liver transplantation. Methods Transplantation liver samples were collected at 3,7,14,28 d after allogeneic or syngeneic mice liver transplantation( n = 4 for each group at one time point). Graft rejection score was given with HE staining. T and B lymphocytes and change of regulatory T cells were identified with IHC staining. The change of Foxp3 mRNA and CLAT-4 on surface of regulatory T cells were detected by real-time PCR and IFC respectively. Results Allogeneic graft was rejected during 2 weeks after transplantation,and the ejection receded generally after 2 weeks. Inflammatory cells intra-graft was mainly T lymphocytes. Foxp3 positive cells and mRNA of Foxp3 in allogeneic graft group was significantly higher than these in isogeneic graft group( 15. 0 ± 1. 3vs. 2. 7 ± 1. 0,P 0. 05). Meanwhile,expression of CLAT-4 on regulatory T cells also was higher in allogeneic graft group compared with isogeneic graft group( 53 % ± 3 % vs. 13 % ± 2 %,P 0. 05). Conclusions The immunity rejection after allogeneic liver transplantation achieved negative regulation and achieved immune tolerance by regulatory T cells.