Inhibitive effect of IL-35 on cardiac allograft rejection in mice / 中华器官移植杂志

ABSTRACT

Objective To investigate the action mechanism of IL-35 gene transfection ameliorating cardiac allograft rejection and prolonging allograft survival.Methods pEBI3-L-p35-Fc plasmid was amplified by polymerase chain reaction.In vitro plasmid DNA pEBI3-L-p35-Fc or pSec-L-Fc was,respectively,transfected into HEK293 cells using Lipofectamine 3000.At 48 and 72 h after transfection,IL-35 concentration in culture supernatant of transfected HEK293 cells was detected by ELISA.Balb/c and C57BL/6 splenocytes treated with mitomycin (MMC) served as the stimulators,those not treated with MMC as responders,and they were subjected to one-way mixed lymphocyte culture (MLC).In the presence or absence of IL-35,the percentage of CD4+ CD25+ Tregs was detected by flow cytometry.Abdominal heterotopic heart transplantation model was established by using inbred male Balb/c mice as donors and C57BL/6 as recipients respectively.In experimental group,recipients were intravenously administrated with IL-35 plasmid (50μg) on the day 1 to day 3 post-transplantation.The control mice were treated with normal saline.The IL-35 expression in the blood,CD4+ CD25+ Tregs proportion in the blood and spleen,and the survival and the histopathologic changes of the cardiac grafts were also observed.Results In vitro the transfected HEK293 cells expressed IL-35.IL-35 enhanced the proliferation of CD4+ CD25+ Tregs of MLC in vitro.The median survival time of the cardiac grafts in experimental group (16 days) was significantly longer than in control group (7 days) (P＜0.01).As compared with control group,CD4+ CD25+ Tregs proportion was significantly increased (P＜0.01),CD8+ T cells proportion was decreased (P＜0.01) and the proliferation of lymphocytes and monocytes infiltration was inhibited in the experimental group.Conclusion IL-35 could alleviate cardiac allograft rejection and prolong cardiac allograft survival via the induction of proliferation and differentiation of CD4+ CD25+ Tregs and inhibition of proliferation of CD8 + effector T cells.