Objective To establish the rat orthotopic liver transplantation model by characterizing the blood supply of hepatic artery with the Cuff skill and the modified arterial sleeve anastomosis, to explore the possible mechanisms of acute rejection and the express of Fractalkine (Fkn) in the early stage after hepatic allograft operation. Methods SD rats were selected as donors and Wistar rats as receptor for the rejection model of orthotopic liver transplantation. Recipient rats were divided into 2 groups randomly after operationand the drugs were given intraperitoneally once a day in each group. In the experimental group, cyclosporine A (CsA) was delivered with 3 mg/kg. In the control group, only normal saline was given with 3 ml/kg. Condition of survivals were observed. The rejection actvity index (RAI) and the expression of Fkn of liver tissue were observed after 3rd, 5th and 7th days in 5 rats. The rest of rats in each group were fed and given drug or normal saline until they were died and the mean survival time were recorded. Results There were 18 survivals in control group, and 19 in experimental group after liver transplantation. Condition of survivals in experimental group was better than that of control group. The mean survival times of experimental group(19.50±4.51 days) was significantly longer than that of control group(7.60±1.60 days), showing statistically significant difference (P＜0.05). After 3rd, 5th and 7th days of transplantation, RAI of control group were 3.80±0.35,5.90±0.87 and 7.50±1.30,respectively;RAI of experimental group were 3.10±0.21,3.90±0.41 and 4.50±0.52.Therewasstatistically significant difference in RAI between 2 groups on the 7th day after transplantation (Plt;0.01). On the 3rd,5th and 7th days after transplantation, the Fkn of control group was 8.20±0.57,21.30±3.30 and 25.70±4.91, and that of experimental group was 8.30±0.56,10.30±0.67 and 11.70±1.23. There were statistically significant differences in Fkn between 2 groups on the 5th, 7th days after transplantation (Plt;0.01). Conclusion Fkn is a participant inacute rejection after the rat orthotopic liver transplantation and can be chosen as a useful target in the diagnosis of acute rejection. CsA has immunosuppressive property in the condition of acute rejection in the rat orthotopic liver transplantation, which may be result from the decreased the level of Fkn.
Insufficient supply of organ for allotransplantation made the study on finding new organ resources from animal progress. Pig is regarded as one of the optimal donor animals for human. The major obstacle in this field is hyperacute reaction (HAR), which is triggered after the xenogenic natural antibodies preexisting in recipient blood combine to the antigens on the surface of the endothelium and activate the complement system. alpha-Galactose residues (alpha-Gal) on the endothelial cell have been identified as the major xenoantigens. NJZ Pig has been closely breed since 1938, whose family history is clear. Tissue samples from heart, liver, kidney, pancreas, lung, small intestine, skin, spleen, thymus and lymph node were obtained and embedded in paraffin. The sections were performed the immunohistochemical staining with the sera from health volunteers (including all the blood types) as the primary antibodies as well as the biotin labeled bandeirae simplicifolia I isolectin B4 (BS I-B4), which has specific affinity to alpha-galactose. All the staining sections were compared with the tissues digested with alpha-galactosidase. There was no difference between the antigens recognized by sera of different blood types. alpha-Gal was still the major xenoantigen on the endothelial cells. There might exist non-alpha-Gal antigens on the distal convoluted tubules and collecting tubules of the kidney. There was no alpha-Gal distributing on the secreting part of pancreas, either the islet cells or the matrix cells, but surely on pancreatic duct and vessels. All the antigenity was destroyed after the enzyme digestion except that the small intestine gland still positive with the BS I-B4. alpha-Gal is the major xenogenic antigen in NJZ Pigs. There exist some unknown antigens on the distal convoluted tubules and collecting ducts of the kidney. The blood type of recipient is not the first affair to be considered in pig-to-human xenotransplantation. The specificity of BS I-B4 for the alpha-galactose needs more detail research.
Limitation of donor source for allograft makes the research on xenograft progress. Pig is regarded as one of the ideal donor animals. The major obstacle in xenograft is hyperacute rejection, which is caused by complements after they are activated by xenogeneic antigens combined with natural antibodies. It has been confirmed that alpha-Gal is the major target antigen, whose expression is incharged by alpha-1,3 galactosyltransferase (alpha-GT). The approaches to overcome hyperacute rejection against alpha-Gal included: immunoadsorption of xenogeneic natural antibodies, lysis of antigen by enzyme and genetic manupilation to obtain animal lack of alpha-GT. Besides alpha-Gal, there were other antigens binding to human serum antibody, such as gp65 and gp100, which was expressed on PAEC after induced by TNF, the A-like antigen. But their function was still unknown. It was debatable on the role of MHC in xenograft. Both direct and indirect pathway were involved in cellular response in xenograft.
【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.
Objective To study the effect of recombinant lentiviral vector mediated human hepatocyte growth factor (hHGF) gene-modified bone marrow mesenchymal stem cells (BMSCs) on the immunological rejection after allograft l iver transplantation in rats, and to reveal the mechanism of immune tolerance. Methods Eight male Sprague Dawley (SD)rats of clean grade (aged 3 to 4 weeks, weighing 75-85 g) were selected for the isolation and culture of BMSCs; 64 adult male SD rats of clean grade (weighing 200-250 g) were used as donors; and 64 adult male Wistar rats of clean grade (weighing 230-280 g) were used as receptors. After establ ishing a stable model of rat allogeneic l iver transplantation, 1 mL sal ine, 2 ×106/mL of BMSCs 1 mL, 2 × 106/mL of BMSCs/green fluorescent protein 1 mL, and 2 × 106/mL of BMSCs/hHGF 1 mL were injected via the portal vein in groups A, B, C, and D respectively. Then the survival time of the rats was observed. The hepatic function was determined and the histological observation of the l iver was performed. The hHGF mRNA expression was detected by RT-PCR, the level of cytokine including hHGF, interleukin 2 (IL-2), IL-4, IL-10, and interferon γ (IFN-γ) by ELISA assay, the level of apoptosis by TUNEL method, and the expression level of prol iferating cell nuclear antigen (PCNA) by immunohistochemical method. Results The survival time of group D was significantly higher than that of groups A, B, and C (P lt; 0.01); the survival time of groups B and C was significantly higher than that of group A (P lt; 0.01), but there was no significant difference between group B and group C (P gt; 0.05). RT-PCR demonstrated the transcription of hHGF mRNA in the grafts of group D; the serum cytokine hHGF reached to (6.2 ± 1.0) ng/mL. Compared with groups B and C, group D exhibited significant inhibitory effect, significantly improved l iver function, and showed mild acute rejection. In addition, the levels of cytokine IL-2 and IFN-γ decreased; the levels of cytokine IL-4 and IL-10 increased; the level of apoptosis reduced; and the expression level of PCNA increased. Except for the expression of IL-4 (P gt; 0.05), there were significant differences in the other indexes between group D and groups B, C (P lt; 0.05). Conclusion BMSCs/hHGF implanting to rat l iver allograft via portal vein can induce immune tolerance. Compared with injection of BMSCs alone, BMSCs/hHGF treatment can alleviate acute rejection and prolong the survival time significantly. The immunosuppressive effect of BMSCs/hHGF is correlated with Th2 shifts up of Th1/Th2 shift, reduced apoptosis, promoted l iver regeneration.
Objective To investigate the mechanism of hyperacute rejection (HAR) in pig to rhesus monkey vein xenograft. Methods Porcine femoral vein was transplanted into rhesus monkey. Deposits of IgM, IgG, C3 and C4 on the grafts were observed by immunoflurescence. Results Great deal of IgM, C3 and C4 were seen along the endothelium of donor vein, but IgG was not seen. ConclusionIn pig to monkey xenograft model, HAR is intiated by the binding of xenoreactive IgM to donor xenoantigens and followed by the activation of complement via the classical pathway.
Objective To study whether the porcine endothelial cells (PECs) lines transfected by HLA-G1 can alter the lysis mediated by human peripheral blood mononuclear cell (PBMC) and natural killer cell 92(NK-92). Methods By use of liposomes pack, the pcDNA3.0 eukaryotic expression vector carrying HLA-G1 was transfected into PECs. Using indirect immunofluorescence and RT-PCR assays, the HLA-G1 expression in PECs was detected. The alteration of the lysis mediated by PBMC and NK-92 was detected by51Cr-release assays. Results HLA-G1 expression could be detected in PECs after transfection of HLA-G1 at the levels of protein andRNA. It also could be found that the survival rate of transfected PECs was muchhigher than that of non-transfected PECs, when both of them faced the lysismediated by human PBMC and NK-92.After transfecting the expression of HLA-G1 could be found in the transfected PECs and the lysis mediated by PBMC and NK-92 to PECs decreased obviously (Plt;0.05). Conclusion The PECs- transfected by HLAG1 can decrease the NK lysis, so that it may provide us a new thought to inhibit the xeno-cell-rejection.
【Abstract】Objective To evaluate the pathological diagnosis of liver allograft rejection. Methods Literatures about diagnosis of liver transplantation rejection in recent ten years were reviewed.Results Humoral rejection was rare. The main features were graft blood vessel thrombosis and liver damage and necrosis about some days or one week after transplantation. The humoral rejection of liver graft occurred later than that of kidney and heart transplantation. The diagnosis of acute liver graft rejection was based on Banff Schema. During chronic rejection intrahepatic bile ducts among hepatic lobules in portal area disappeared, and inflammation, fibrosis and stricture of hepatic arteries and veins were found, but the morbidity was less than that of kidney， heart, lung and pancreas grafting. Conclusion Banff standard is the most important base of diagnosing liver graft rejection.
Objective To investigate the effect of nidus vespae on lymphocyte blastisation in mixed culture system of lymphocyte and pancreatic islet. Methods Solution of nidus vespae was extracted with ethanol from its herb. Rat lymphocyte and pig pancreatic islet were isolated and then were mixed together and cultured in incubators of 37 ℃ (concentration in volume: 5%CO2). Three different concentrations of extracted solution of nidus vespae （experimental group Ⅰ: 4.0 g/ml, group Ⅱ: 0.4 g/ml, group Ⅲ: 0.2 g/ml） were added to the mixed culture system of lymphocyte, respectively. Radioactive nuclide counts per minute were measured by 3H-thymdine test in order to examine the role of nidus vespae in inhibiting blatisation of lymphocyte, and the results were also compared with control group and CsA group, respectively. Results The counts were all reduced significantly (P＜0.001) in 3 experimental groups compared with control group (group Ⅰ 45.3%, group Ⅱ 29.6%and group Ⅲ 9.2%). It also showed that the inhibitory effect became ber in higher concentration but still weaker than that in CsA group (80.7%). Conclusion Nidus vespae could inhibit the blastisation of lymphocyte in mixed culture system of lymphocyte and pancreatic islet, and the effect increased as the the concentration increased, which may suggest that nidus vespae could suppress the rejection induced by T cells.