Expression of Th1/Th2 cytokine and T lymphocyte subset in rat allogenic corneal transplantation with organcultured graft / 中华实验眼科杂志

ABSTRACT

BackgroundAllogenic immunological rejection is still the common cause of keratoplasty failure.Organ culture is a good choice for gradually attenuating corneal antigeniciy.However,the complicated regulatory mechanism of such allogenic rejection with organ culture gratts is unclear until now.ObjectiveTo investigate the changes of several Thl/Th2 cytokines and T lymphocyte subsets in the rat corneal allogenic transplantation rejection with organ culture grafts.MethodsThirty-six SPF Wistar rats served as donors,and 72 SPF SD rats served as recipients in this study.Seventy-two SD rats were divided into two groups randomly.Organ culture and fresh grafts from Wistar rats were performed on 36 recipients SD rats,respectively.Six normal SD rats were served as the normal control.After transplantation,graft survival time was observed ; Aqueous humor levels of IL-2,IFN-γ,IL-4 and TNF-α were measured by enzyme linked immunosorbent assay.Immunohistochemistry was performed to examine CD25 expressions in grafts.Levels of TNF-αmRNA,IFN-γmRNA,IL-4mRNA and CD25mRNA in grafts were detected by using reverse transcription polymerase chain reagction.The levels of CD28subsets in peripheralblood were determined by Flow Cytometry.The use of experimental animals followed the Statement of ARVO.Results The mean rat graft survival time was longer in the organ culture grafts group( 13.78 d) than that with fresh gratts( 10.56 d)(t=14.945,P =0.000 ).The aqueous humor levels of IL-2,IFN-γ,IL-4 and TNF-α were higher in two allograft groups at day 6,day 13 and day 24 after transplantation than that in the normal control,which peaked at day 13,and the fresh grafts group had the highest level( F=324.891,416.416,240.661,364.533,P=0.000).At day 13,CD25 was weakly expressed in frozen section of two operation groups.The expression of TNF-α and IFN-γmRNA in organ culture grafts group was markedly less than in fresh grafts group at day 13 after surgeries (t =2.464,P =0.039;t=5.438,P=0.001 ),whereas there was no significient difference in IL-4 and CD25 mRNA levels between them (t=-0.782,P =0.457,t =0.712,P =0.497).The percentages of CD28 of the fresh graft group increased significantly and more weakly expressed in organ culture grafts group (P =0.016 ). Conclusions Th1/Th2 cytokines and CD28 lymphocyte subsets may play important roles during corneal allograft rejection with organ culture grafts.