Objective To summarize the research progress of xenotransplantation.Methods Domestic and international publications about xenotransplantation were summarized and reviewed. Results Hyperacute xenograft rejection was a huge problem for xenotransplantation， but it could be alleviated if the organs or tissues of donor were genetically modified. So far the graft survival time differed greatly due to characteristics of different organ. Conclusions By reviewing the studies of relevant papers about xenotransplantation， a comprehensive understanding of research background and a suitable research direction of xenotransplantation can be supplied. The graft organs or tissues from genetically modified donors are expected to avoid or alleviate hyperacute xenograft rejection.
Objective To observe the dynamic histopathologic changes of acute rejection in rat orthotopic liver transplantation (OLT) model after tacrolimus discontinued and provide some prediction and evaluation data for clinical acute rejection after liver transplantation. Methods Kamada two-cuff technique was used to establish 60 rat OLT model， and male DA rats, male Lewis rats were used as donors and recipients respectively. Therapeutic amount of tacrolimus (0.05 mg/kg, twice per day, continued for 8 d, 1 d before operation and 7 d after operation, intragastric administrated) was administrated to recipients, then continuously half dose was decreased every day beginning from day 8 after operation and tacrolimus administration was stopped on day 13. Liver tissues were collected on day 7, 14, 21, and 28 after liver transplantation. Histopathologic changes and rejection activity index (RAI) of liver tissues were observed, survival time of recipients was calculated. Results Owing to protection effects of tacrolimus, liver tissues displayed no significant histopathologic changes of acute rejection in 7 d after OLT, while typical acute rejection histopathologic changes began to be observed on day 14 after OLT due to tacrolimus discontinuation. On day 14, 21, and 28, RAI were 3.7±0.9, 6.3±0.9, and 8.1±0.7 respectively. Survival time of recipients was (20.85±0.71) d with a median of 21 d. Conclusion Acute rejection could be induced in rat OLT model after tacrolimus discontinuation, and data collected from this model shows some extent of predictive value and assessment value for clinical liver acute rejection.
Objective To study the mechanism of immune hyporesponsiveness of allograft rejection induced by transfusion nonpufsed allopeptide syngeneic immature dendritic cell (imDC) generated from recipient bone marrow progenitors and to explore a possible strategy for liver allograft protection in clinic. Methods Forty experimental rats were randomly divided into 4 group: control group, cyclosporine A (CsA) group, mature DC (mDC) group and imDC group. In control group, Wistar rats only received liver transplantation. In CsA group, Wistar rats underwent liver transplantation plus CsA treatment 〔10 mg/（kg·d)〕. In mDC group, recipient-derived mDC 1×106 were infused intravenously through the penile vein to Wistar rats. In imDC group, ImDC with the dose of 1×106 were injected into Wistar rats via the dorsum vein of penile. In each group, five recipients were killed on the 10th day after transplantation, the other five recipients were left to observe survival time. The levels of ALT, AST, TBIL, IL-2, IFN-γ, IL-4 and IL-10 were detected. The acute rejection and the expression of FasL/Fas in the grafts were detected by HE and immunohistochemical staining. Western blot was used to detect Scurfin protein expression of CD4+ CD25+ T cells. Results The median survival time of the liver allografts in CsA group and imDC group were significantly longer than that in control group and mDC group ( P ＜ 0.05). The levels of ALT and TBIL in control group and mDC group were significantly higher than those in CsA group and imDC group ( P ＜ 0.05). Compared with CsA group and imDC group, the levels of IL-2 and IFN-γ were higher but the levels of IL-4 and IL-10 were lower in control group and mDC group ( P ＜ 0.01). Slightly or no rejection reaction was found in CsA group and imDC group ( P ＜ 0.05). The Scurfin protein expressions of CD4+ CD25+ T cells of imDC group were significantly higher than those of other three groups. Conclusion Application of nonpufsed allopeptide syngeneic recipient-derived imDC is an effective way to induce immune hyporesponsiveness by blocking indirect recognition in rat liver transplantation model. Survival span is significantly prolonged by its protective effect. The mechanism of immune hyporesponsiveness induced by imDC transfusion might be involved in some aspects: T cell apoptosis, immune deviation of Thl/Th2 cytokine net and inhibition of T lymphocytes responsiveness by regulatory T cells.
Objective To investigate the inhibitory effect and its mechanisms of TLSFJM (JM acute T leukemia cell line derived suppressor factor) on allograf t rejection of small bowel t ransplantation in rat , and to compare the effect s and complications of TLSFJM with those of FK506. Methods One hundred male Brown Norway (BN) rats and 100 Lewis(L EW) rat s were t reated as donors and recipient s of small bowel t ransplantation , respectively. Then they were divided into five groups according to the dose of administ ration of TLSFJM and/ or FK506 : small bowel transplantation group (SBT group) ; large dose of FK506 〔0. 5 mg/ ( kg ·d) 〕group ; small dose of FK506 〔0. 25 mg/ (kg ·d) 〕group ; TLSFJM 〔10 U/ ( kg ·d) 〕group ; TL SFJM 〔10 U/ ( kg ·d) 〕associated with small dose of FK506 〔0. 25 mg/ (kg ·d) 〕group. FK506 and TLSFJM were administered through int ramuscular or int raperitoneal injection , respectively. Survival time , body weight , hepatic and renal function and histopathology of recipient s in each group were observed. Results TLSFJM took no damage effect on the recipient s’renal and hepatic functions 7 days after administ ration. When TLSFJM was administ rated associated with small dose of FK506 in small bowel transplantation , it could not only effectively suppress rejection reaction , extend recipient’s survival time , but also decreased the dosage of FK506 and prevented the side effect s. But TLSFJM may not be used as immunosuppressive agent alone for the prevention and treatment of rejection in rat small bowel t ransplantation because the rejection still existed. Conclusion As an effective immunosuppression agent , TLSFJM associated with small dose of FK506 can prolong the survival time of both recipients and graf ting small bowel , relieve intensity of rejection , and prevent the side effect s when high dosage FK506 is administ rated. TLSFJM may be used as a high-efficiency , low-toxicity immunosuppresive agent in small bowel transplantation.
Objective To investigate the roles of cell apoptosis and the gene expressions of Fas, FasL, bcl-2 and bax in acute rejection of pancreaticoduodenal transplantation and to evaluate the function of duodenum biopsy for early detection of rejection in rats. Methods Wistar and SD rats were divided into two groups: ①Wistar rats that underwent allogenic pancreaticoduodenal transplantation from the organs of SD rats; ②Wistar rats that received homogenic transplantation. The grafts were then harvested on day 3, 5 and 7 after the transplantation, and all graft samples were observed with HE staining and TUNEL was also used to detect apoptotic cells. The expressions of Fas, FasL, bcl-2 and bax were measured by immunochemical method. According to Nakhleh’s score, pathologic features of transplanted pancreas and duodenum were ranged from one to three scores in order. Results The percentage of same or different scores between the pathological scores of pancreas and duodenum in allogenic pancreaticoduodenal transplantation group were 61.1% (11/18) and 38.9% (7/18) respectively, and there were 6 specimens of pancreatic tissue got higher scores with only one higher score for duodenum. There were significant differences of histopathologic rejection scores and apoptotic indices between the two groups, respectively (P＜0.05， P＜0.01). Apoptotic indices of pancreas and duodenum both showed positive correlations with histopathologic rejection scores (r=0.965， P＜0.01; r=0.942, P＜0.01). The rejection score and apoptotic index elevated, the expression of FasL increased, bcl-2 decreased, and Fas and bax changed over time after operation. Conclusion Apoptosis maybe significantly positive correlated with the degrees of damage of the acute pancreaticoduodenal allograft rejection, and the apoptotic index maybe valuable to estimate the damage. FasL and bcl-2 were significantly related to the impairment of acute pancreatic allograft rejection as well. Duodenum biopsy may contribute to the early diagnosis of the rejecting transplanted tissues.
【Abstract】Objective This study was conducted to build experimental model of orthotopic liver transplantation in rat (ROLT) with the character of acute rejection; and to study the effect of cytotoxic T lymphocyte antigen 4 immunoglobulin G (CTLA4Ig) on prevention of rejection and the induction of immune tolerance of ROLT. Methods Build model of Wistar→SD ROLT(performed by the two cuff method) with character of acute rejection.Recipients were injected with CTLA4Ig 75 μg per ROLT into abdominal cavity after 2 days of operation. Contrast was made with no treatment group, the clinical characters, the liver function, the transplantated liver pathologic character and the concentrations of TNFα in serum were observed and measured on postoperative day 7. In treatment group, all above observation were done on postoperative month 4. Above all, determination of the effect of CTLA4Ig on preventing acute rejection and inducing tolerance in ROLT was observed.Results ①Recipients (no treatment group) died one by one within 6th～14th days; pathologic character of rejection in transplantation liver could be found; ② In treatment group, on postoperative day 7 and month 4, no clinical rejection character and no pathologic character of rejection in transplantation liver were found and serum concentration of cytokins related to TNFα found lower than that of contrast group(P＜0.05), and serum concentration of ALT、AST、TBIL、DBIL found lower too(P＜0.05); But serum concentration of TP and Alb was found higher than that of contrast group(P＜0.05). Conclusion ① CTLA4Ig treatment alone inhibits the rejection responce in ROLT. ② CTLA4Ig treatment can Prevent rejection and induce immune tolerance in ROLT model with characters of acute rejection; the serum concentration of cytokins related to TNFα can probably be used as evaluation standard of rejection in ROLT rejection.
【Abstract】ObjectiveTo explore the effects of p38 mitogenactivated protein kinase (MAPK) on apoptosis of small intestinal epithelial cells after transplantation in rats. MethodsSmall intestinal transplantation was performed in SD and Wistar rats. The recipients were divided into three groups: isograft group (Wistar→Wistar group), allograft group (SD→Wistar group) and allograft+cyclosporine A group (SD→Wistar+CsA group). The grafts were harvested on day 1, 3, 5 and 7 after operation. All graft samples were subjected to histological examination. The apoptosis of graft epithelial cells was detected by TUNEL method. p38 MAPK was measured by Westernblotting method and serum TNFα was determined by ELISA. ResultsMild, moderate and severe rejection reaction occurred in the SD→Wistar group, it was showed that the number of apoptotic cells increased with the severity of the rejection reaction by TUNEL. In SD→Wistar group, the numbers of apoptotic cells were significantly higher than those of the other two groups （P＜0.01）. The severity of rejection reaction in SD→Wistar+CsA group was less than that of SD→Wistar group and the number of apoptotic cells increased with the severity of the rejection reaction (P＜0.01). The level of serum TNFα varied with the apoptotic degree of small intestinal epithelial cells in SD→Wistar group and SD→Wistar+CsA group （P＜0.01）. The expression of p38 MAPK increased with the number of the apoptotic cells in SD→Wistar group and SD→Wistar+CsA group （P＜0.01）, but there was no evident change in Wistar→Wistar group （Pgt;0.05）. The expression of p38 MAPK and the level of serum TNFα were positively correlated with apoptosis in small intestinal rejection after transplantation （r=0.875， P＜0.01； r=0.837， P＜0.01）. p38 MAPK and TNFα were also positively correlated （r=0.826，P＜0.01）. ConclusionApoptosis plays an important role in small intestinal rejection. p38 MAPK is involved in apoptosis and is an important regulator in signal pathway of cell apoptosis.
目的探讨肝移植后育龄妇女的怀孕及分娩对胎儿的影响。方法分析了中国大陆首例肝移植妇女肝移植、免疫抑制剂使用及成功怀孕和分娩的情况。 结果本例妇女因硬化性胆管炎，胆汁性肝硬化，肝脓肿，脾大而行同种原位肝移植术，术后2年9月第二次成功怀孕并分娩出发育正常的男婴。结论肝移植后育龄妇女同样可以正常怀孕，但是发生早产和胎儿发育相对迟缓的几率增加；怀孕过程中应该严密地监控母亲的器官功能改变和胎儿的发育情况，并且应合理选择和使用免疫抑制剂。
ObjectiveTo compare tacrolumus (FK506) with cyclosporine A (CsA) in clinical application to organ transplantation.MethodsThe literature in recent years has been reviewed and compared. ResultsFK506 was a powerful immunosuppression with a mechanism of action similar to that of CsA, but significantly superiori to CsA in terms of prophylaxis and treatment of allograft acute rejection, delay of chronic rejection, and withdrawal of steroid in early period. The cardiovascular mortality and chronic graft nephropathy (CGN),such as hypertension and hyperlipidemia were less frequently seen in FK506treated patients and FK506 also had an acceptable safety profile, including a low incidence of hypertrichosis,gingival hyperplasia and infections.However, CsA had been showed a better result in prevention of posttransplantation diabetes mellitus (PTDM ) and more economic agent than FK506. Pharmacokinetic studies showed CsA in the form of Sandimmun Neoral showed less inter an intrapatient variability than FK506.Meanwhile, the combination of MMF and FK506 or CsA has been proved effectively with excellent graft and patients survival. Conclusion FK506 and CsA are safe and effective long term maintenance immunosuppressive agents in organ transplantation with wonderful prospect.
ObjectiveTo investigate the aim antigen coursing the hyperacute rejection of xenotransplantation. MethodsDocuments about hyperacute rejection in xenotransplantation were reviewed and summarized in detail. ResultsPig is thought to be one of the ideal donors of xenotransplantation, but the major obstacle is hyperacute rejection mediated by complement that is activated though human serum. αGal is recognized as the major antigen and its expression is controlled by α1,3 galactosyltransferase. Immunoabsorption of preexsisted antibody, enzymatic digestion of αGal, knockout αGT gene and transgenic technology have been used to solve this problem. Even so, there remain other antigens which can combine with natural antibodies in human serum, such as, 40×103 molecule in erythrocyte, 210×103, 105×103 and 50×103 antigen in pig embryo brain cell, etc. Conclusion αGal is the major antigen which course the hyperacute rejection. Besides αGal, many nonalphagal need further investigation.