Abstract:Objective:To investigate the potential mechanism of antigen-specific CD4+CD25+ regulatory T cells on the suppression of rejection for allogenetic islet transplantation in vivo.
Methods :Islets with 8×105 antigen-specific Treg were allogeneically transplanted under the kidney capsule of streptozotocin-induced diabetic BALB/cByJ mice. Mean survival time(MST), the ratio of CD4+/CD8+ T cells, cytokine expression in both tolerant and rejected mice was detected.
Results:In vivo, the mean survival time of recipients with islets and antigen-specific CD4+CD25+ Treg group (C group) was (34.57±17.15) days, whereas transplanted islets without Treg treatment (B group) survived a mean time of (10.60±1.82)d(P<0.01). The ratio of CD4+/CD8+ T cells from antigen-specific CD4+CD25+ Treg transplantation group was significantly lower than that from islet transplantation group (P<0.01). The mRNA expressions of IL-10, TGF-β were upregulated in antigen-specific CD4+CD25+ Treg transplantation group. However, the mRNA expressions of IL-1β, IL-2, IFN-γ were similarly upregulated in islet B group.
Conclusions:Allogeneic antigen-specific CD4+CD25+ Treg cells can prolong islet graft survival by the mechanism of affecting Th2/Th1 cells responses.