The anti-rejection effect of blocking BT/CD28 co-stimulatory pathway by RNA interference in mice heart transplantation / 中华器官移植杂志

ABSTRACT

Objective To explore the influence of blocking B7/CD28 co-stimulatory pathway by RNA interference on the rejection response in mice heterogeneous heart transplantation and its mecha- nism.Methods siRNA of which sequence specified to CD80 and CD86mRNA was synthesized in vitro respectively and transfected into donor derived myeloid dendritic cells (DCs).The expression levels of CD80 and CD86 mRNA and surface antigen CD80,CD86 were assayed by semi-quantitative reverse transcription polymerase chain reaction and flow cytometry before and after CD80siRNA and CD86siRNA transfection.Seven days prior to heterogeneous heart transplantation in mice,DCs modi- fied by siRNA were transfused into recipients intraveneously (DC interference group).At the same time,group of allograft transplantation,cyclosporine A (CsA)-treated (CsA injected subcutaneously postoperatively,5 mg.kg~(-1)?d~(-1)) group,group of isograft transplantation,and non-interference DC group (transfusion of non-interfered DCs pre-transplanting) were assigned.The graft survivals were individually recorded and the graft rejection grading was pathologically evaluated.Interleukin 2 (IL- 2),interferon?(IFN-?),and IL-10 mRNA expression levels in grafts tissue were determined.Results After siRNA transfected into DC,the expression levels of CD80 and CD86 mRNA were down- regulated significantly and the the antigen CD80~+ and CD86~+ reduced from 84%,67% to 35% and 30% respectively.As compared with groups of allograft and non-interference DC,survival of the grafts was significantly longer in DC interference group (P＜0.01),pathological grade of rejection significantly lower (P＜0.01),IL-2 and IFN-?mRNA expression levels lower,and IL-10 mRNA ex- pression levels higher in grafts tissue (P＜0.01).Conclusion Knocking down the molecule B7 expres- sion level in donor-derived myeloid DCs through RNAi,which could block B7/CD28 co-stimulatory pathway,could exhibit inhibitive effect on rejection response in mice heart transplantation.The mechanism might be due to induction of T lymphocyte anergy and Th cell differentiation deviating to T_H2.