Tim-1 Blockade With RMT1-10 Modulatedendritic Cells And Prevents High-risk Corneal Allograft Rejection In Mice

Objective:Corneal allograft rejection is an immunological hypersensitive reaction caused by the antigenicity of the donor cornea.Our study aimed to explore the effects of RMT1-10 on the prevention of corneal graft rejection by modifying immunological characteristics of dendritic cells(DCs).Methods:Flow cytometry was used to separate DCs and CD4+T cells,and a mixed lymphocyte culture system was established in vitro.The culturedcells were prepared for the characterizationof the DCs phenotypes using the markers CD11 c,CD80,MHC-II,CD54,and TIM-4.The concentrations of IL-4,IL-12 and IL-10 in the supernatant were detected by enzyme-linked immunosorbent assay(ELISA).Flow cytometry was used to detect the effect of RMT1-10 on the apoptosis and proliferation inhibition of CD4+T cells.Mouse model of high-risk corneal transplantation was established to observe the effect of RMT1-10 treatment on corneal graft survival and the regulation on DCsphenotype and function.The donor and receptor were C57 BL / 6(H-2b)and BALB / C(H-2d)mice,respectively.After RMT1-10 treatment,DCs of mice without rejection were transferred to third party recipients to observe whether antigen-specific immune tolerance was induced.Results:RMT1-10 inhibited the expression of CD11 c,CD80,MHC-II,CD54 and TIM-4 on the surface of DCs and the production of IL-12 and IL-10 in the supernatant.RMT1-10 can inhibit the proliferation but not affect the apoptosis of CD4+T cells,but this inhibition must be indirectly controlled through DCs.RMT1-10 significantly reduced the local and systemic inflammatory response of the recipients: the edema,neovascularization and opacity of corneal grafts were significantly reduced;the percentages of CD4+T cells,TIM-4+cells and CD11c+cells in corneal grafts,spleens and lymph nodes were significantly reduced;IL-4,IL-10 and IL-12 in peripheral blood were significantly reduced.The rejections of recipient's corneal allografts receiving DCs adoptive transfer were also inhibited.Conclusion:RMT1-10 significantly improved the survival of high-risk corneal transplantation in mice.The mechanism may attribute to the immature DCs directly regulate the activation,proliferation of CD4+T cells,and induce the receptor to produce antigen-specific immune tolerance.In addition,RMT1-10 may also regulate the maturation and migration of DCs by reducing the inflammatory response of recipients and inhibiting corneal neovascularization,thus preventing the occurrence of high-risk corneal allograft rejection.