The Research On Changes And Mechanism Of CD45 Molecule Following Small Bowel Transplantation In Rats

The Research on Changes and Mechanism of CD45 molecule following Small Bowel Transplantation in Rats(The Project Supported by Natural Science Foundation of Tianjin,983601811) Objective In order to explore the feasibility of CD45 molecule and its splice isoforms taking a role of earlier rejection marker following small bowel transplantation, the alteration of relevant lymphocytic subsets to CD45 in peripheral blood and CD45 molecule and its splice isoforms mRNA transcription were investigated following the establishment of heterotopic small bowel transplantation in Inbred strain rats. Meanwhile, IL 2R a chain(CD25) and INF- Y mRNA transcription in grafts were assayed to study the intrinsic mechanism of the immunocompetent cell change in rejection following small bowel transplantation. Method Heterotopic SET models were established with Inbred strain F344/RT11 and BN/ RT1" by microsurgical technique, including Isotransplantation(F344-* F344,n=6) and allotransplantation (BN-*F344,n=6). Samples were harvested on various time points of postoperative day (POD)O, 3, 5, 7 and 9 respectively CD4~CD45^,CD4~CD45RC', CD8~CD45~and CD8TD45R(T subsets and ratios of CD4~CD45RC7CD4~CD45RC~ and CD8TD45RCT /CD8~CD45RC~ in the recipients peripheral blood were assayed with flow cytometry (FCM)on various time points. Quantitative reverse transcription polymerase chain reaction (QRT-PCR) technique was used to determine the mRNA transcription levels of the molecules and cytokines which were CD45,CD45RO,CD45RC, IL-2R a chain and INF- v ,as well as the ratio of CD45RC to CD45RO in grafts of both groups on those time points. All results above were compared with the pathological features of grafts on the same time point. Result Pathological features of allografts showed that no significant structure changes occurred in grafts of both groups on POD3, except for nonspecific slight inflammation. The pathological changes gradually restored in isografts, in contrast, were coincided with diagnosis of mild atypical, moderate and severe acute rejection in allografts on PODS, 7 and 9 respectively. The results detected with FCM showed that no significant differencem CD4~CD45~ and CD8~CD45RCT subsets in the peripheral blood of the two groups postoperatively. In isograft CD4~CD45RC~ cells was significantly increased on PODS, and then rapidly restored to the level of PODO, in the allograft group slowly decreased to the level of PODO after PODS, CD4'CD45RC~ subpopulation in allograft group was significantly higher than that in isograft control on PODS and 7. Ratio of CD4~CD45RCVCD4TCD45RCT was significantly increased on POD3, then fast restored to the level of PODO in isograft control, and in allograft group this ratio was still higer on POD3 and PODS. This ratio in allograft group was significantly higher than that in isograft control from PODS to POD9. CD8TD45RCT subpopulation reached peak on POD3, and then slowly decreased to the level of POD 0 on POD9 in isograft control, and in allograft group was maintained on higher level from POD3 to POD9, the number in allograft group was significantly higher than that in isograft control on POD3, 5, 7 and 9 Ratio of CD8TD45RC7CD8TD45RCT reached peak on POD3 and rapidly decreased to the level of PODO on PODS, in allograft group was significantly higher on POD3, 5, 7 and 9 than that on PODO in allograft group. The ratio of CD8~CD45RC7CD8~CD45RC~ was significantly higher in allograft group than that in isograft control on POD3, 5 and 7. The results detected with RT-PCR showed that no significant difference of CD45 mRNA transcription in grafts on the five various time points in isograft control, CD4S mRNA transcription in grafts was significantly higher on POD9 than that on PODO and POD3 in allograft group, also significantly higher than that on POD9 in isograft control. There were no obvious changes of CD45RO mRNA transcription following SET in isograft control. CD45RO mRNA transcription was significantly inreased on POD7, and which in allograft group was significantly higher than that in isograft control o...