MIC Expression In Mice Allogenic Heart And Skin Transplantation,and Influence Of Cyclosporin A

Objectives Organ transplantation has been the only effective approach of treating the end-stage diseases, but still faced many challenges. CGD (chronic graft dysfunction) is one of the most important factors influencing long-term survival of grafts and recipients, and its mechanism is unclear. AR (acute rejiection) closely related to CGD. The fact that CGD is not avoidable though compatible MHC matching and systematic immunosuppression protocol, suggesting that MIC (MHC class I chain-related antigen), non-MHC and mHC (minor MHC) may play some role in the CGD induction and development. MIC is an inducible antigen, which can activate several kinds of immunocytes to evoke innate and acquired immunity through ligating with its receptor NKG2D. H60 (minor H antigen 60) and Rae-1 (the retinoic acid early molecules) are the homologues of human MIC. Their role is unclear in transplantation immunity. This study is to investigate MIC expression in mice allogenic heart and skin transplantation and the influence of CsA (cyclosporin A) by two classical acute rejection models, exploring whether MIC could play any role in AR and any potential influence for the later CGD.Methods 48 KM (Kunming) female mice were randomly divided into two groups, control group which were performed cervical heart allotransplantation by Cuff (operation group) and treat group (operation withCsA treating group). Grafts were harvested on 1, 3, 5 and 7 days post-transplantation (n=3, for each time point). HE staining was performed to detect histological changes. Total RNA of grafts was extracted and H60 and Rae-1 mRNA were analysis by RT-PCR. The H60 protein was detected by immunohistochemistry.24 KM female mice were also performed skin allotransplantation. Grafts were harvested on 1, 3, 5 and 7 days post-transplantation. Total RNA was extracted and H60 and Rae-1 mRNA was analysis by RT-PCR.Results Cadiocytes arrange regularly and no lymphocytic infiltration in normal heart. Cadiocytes necrosis and progressive interstitial lymphocytic infiltration surrounded vessels can be seen in control group, and less lymphocytic infiltration in treat group.H60 mRNA could be detected in grafted heart on 5th day and up regulated on 7th day post-transplantation in control group. It also was detected on 3rd day, reached the peak on 5th day (but lower than control group) and decreased on 7th day post-transplantation in treat group. But only H60 protein in cadiocytes was detected by immunohistochemistry on 7th day in control group. Rae-1 mRNA was negative at all time points.Both H60 and Rae-1 mRNA were not detected in skin grafts at all time points.Conclusions This study first reported that H60 could be induced at mRNA and protein levels on grafted heart in KM-* KM mice heart transplantation model.The fact that H60 expression was up regulated on 5th daypost-transplantation suggested that MIC might involve in AR and early stage of CGD for heart transplantation. H60 expression in treat group might be induced by CsA's toxicity on 3rd day, and up to peak on 5th day but lower than control group and then decreased on 7th day might be due to CsA's immunosuppressive functions.H60 and Rae-1 mRNA were not detected in skin transplantation suggested that they didn't involve in AR in skin transplantation, and they were possibly related to the intensity of stress.