Objective To clarify the role of B7-H1 in the immune privilege after corneal transplantation in homogeneity variant mice.Methods We established the experimental animal model of allograft mice by using C57BL/6 mouse as donor and Balb/c mouse as recipient.We allocaated the mice with long time survival (＞50 days) corneal graft into survival group,mice with rejection occurring in 50 days into rejection group,and normal C57BL/6 mice into control group.The transplanted corneal grafts were obtained for future reference at the 8th week after transplantation in survival group,and the time of rejection in rejection group.The expression of B7-H1 mRNA was detected by using immunohistochemistry and real time quantitative PCR (RT-PCR),and the relationship between B7-H1 and the immune privilege after corneal transplantation was analyzed. Results The B7 H1 mRNA was highly expressed in epithelium and endothelium of corneal grafts both in survival and control group,in comparison to an obviously lower expression in rejection group.The relative expression level of B7-H1 mRNA was 200.0 ± 11.5 in survival group,44.7 ± 10.8 in control group,and 6.9 ± 12.0 in rejection group,respectively. There were statistically significant differences among the three groups (F=241.164,P＜0.01 ).The was a significant correlation between the level of B7-H1 mRNA and occurrence rate of rejection in corneal graft (P＜0.01 ).Conclusion The results suggest that the immune privilege after corneal transplantation might be mediated by B7-H1,which plays an important role in maintaining the state of corneal immune privilege.

OBJECTIVETo study the expression level of B7-H1 protein in the eyeball tissues of mice receiving corneal allograft transplantation and explore the role of B7-H1 protein in corneal immune privilege.

METHODSMouse models of corneal allograft transplantation were established, and the corneal opacity and angiogenesis index was evaluated according to the Sonoda method. Eight weeks later, the mice were examined for the occurrence of graft rejection, and the expression level of B7-H1 protein in the eyeball tissues were detected by immunohistochemistry, using 8 normal mice as the control group.

RESULTSB7-H1 protein was expressed highly in the corneal and the choroidal/ciliary body in the normal control mice and the survived mice, but was absent in mice with graft rejection.

CONCLUSIONB7-H1 protein may play a role in the immune privilege following corneal allograft transplantation in mice.

Animals ; B7-H1 Antigen ; immunology ; Corneal Transplantation ; Female ; Immune Tolerance ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Transplantation, Homologous ; immunology