Study on cytokines and dendritic cells involving immunologic inhibition of rat high-risk corneal transplantation induced by SEB / 眼科

ABSTRACT

objective To explore the role of cytokines and dendritic cells (DCs) in rat high-risk corneal allograft survival pro- longed by superantigen Staphylococcal Enterotoxin B (SEB) and to compare the different effects between SEB and glucocorticoid. Design Experimental study.Participants Fisher 344 and Lewis rats.Methods The Fisher 344 and Lewis inbred rats were used for high-risk penetrating keratoplasty model.All of the Lewis rat recipients were divided into three groups by blinded fashion.GroupⅠand GroupⅡrats were injected intraperitoneally with 0.2ml saline buffer or SEB (75?g/ml) respectively at 4-day intervals on three occasions before transplantation.GroupⅢrats were injected subconjunctivally with 0.1ml dexamethasone (1mg/ml) daily from the first day after surgery for 2 weeks.The allograft survival was examined under slit-lamp.The concentration of interleukin IL-1?,IL-2,IL-4,IL-5,IL-6, IL-10,TNF-?in rat aqueous humor and peripheral blood were measured by liquichip and the cytokine and CD11c,CD80,MHC-Ⅱex- pression in corneal grafts were examined by immunohistochemestry staining.Main Octcome Measures Mean survival time of the allo- grafts,the level of cytokines in aqueous humor,peripheral blood and corneal grafts.Results Compared with group control,the grafts mean survival time was delayed about 3.8d in group SEB (P=0.00) and 7.1d in group dexamethasone(P=0.01).But there was no signifi- cant difference between group SEB and dexamethone (P=0.26).Liquichip test showed that the level of IL-1?in aqueous humor was re- duced and IL-4,IL-6 and IFN-?,ascended.Only IFN-?,and IL-6 could be found in peripheral blood,and the changing shift of them was similar to that in aqueous humor.The immunohistochemistry staining showed that the expression of IL-2 in rat corneal grafts was signif- icantly decreased but IL-4,IL-6 and IL-10 elevated.The expression of DCs in group SEB was similar to that in group control,which was elevated after keratoplasty,but the phenotype of DCs was not the same.There were predominantly mature DCs in group control while immature DCs in group SEB.Conclusions The immunological inhibiting effect of SEB is same to glucocorticoid,but the mecha- nism is different.SEB can modulate immune response,which might induce immune inhibition via the local production of cytokines and effect on DCs maturation involving corneal graft rejection prevention.