IT HAS been well proven that donor-specific antigens (DS-Ags) could induce immunologic tolerance of recipients and prolong allograft survival. But the detailed mechanisms are still unclear. The effect of the DS-Ags is influenced by some factors, particularly the species, the histocompatibility barries, the different sources of the DSAgs, the different pathways that the DS-Ags were given, the dose and timing of DS-Ags infusion, the immunoreactivity of the recipient to DS-Ags, etc. In this study, different DS-Ags and different pathways through which the DS-Ags were given were compared.

ONE OF the serious problems in allogenic clinical transplantation is the shortage of grafts. The pig is now widely accepted as the most appropriate candidate for xenotransplantation.1 It is very important to establish a large animal model to mimic pig-to-human xenotransplantation and to evaluate the donor-recipient interaction during the whole course in vivo. Our previous study showed that human bone marrow and spleen cells could survive in recipient pig for a long time after transplant. In this study, human spleen or spleen tissue was transplanted into pig to establish a higher level of chimerism. Therefore, it is possible to observe the interaction of human against pig, and it might be possible to develop xenogenic graft-versushost disease (xGVHD).

ORGAN transplantation has become a realistic treatment for patients with end-stage organ failure.1,2 However, despite improvements in diagnosis and treatment of acute rejection, the consequences of chronic rejection, namely transplant arteriosclerosis, remain major obstacles to long-term survival of most solid organ allografts.3,4 Several animal models have been developed to investigate the mechanisms of the chronic rejection.5-7 However, most of these models have the disadvantages of requiring difficult operative skills, ensuring high rates of postoperative complications and host mortality as well as requiring a long time of observation. The present study was designed to investigate the feasibility of using SD and Wistar rats to design a new rat model of transplant arteriosclerosis and to accelerate the process by enhancing the ishemia/reperfusion (IR) injury.

To screen different combinations of prostate-specific membrane antigen (PSMA) promoter/enhancer with the strongest transcriptional activity in prostate-specific cells, we used PSMA regulatory elements to control specific expression of the target gene in gene therapy of prostate adenocarcinoma. PSMA promoter and enhancer DNA sequences were amplified from the LNCaP human prostate cancer cell line by polymerase chain reaction, then recombinant plasmids of the enhanced green fluorescent protein (EGFP: pEGFP-PSMAPro, pEGFP-PSMAE-P, pEGFP-PSMAE(r)-P, pEGFPPSMA E(d)-P, and pEGFP-PSMAE(t)-P) were constructed with molecular clonal techniques. At the same time, all experimental cell lines were analyzed for the expression of PSMA with the use of PSMA monoclonal antibody and the ABC immunohistochemical assay kit. After plasmids were transfected via liposome, we observed the expression of the reporter gene (EGFP) under a fluorescent microscope and compared the different levels of EGFP expression with reverse transcriptase polymerase chain reaction and flow cytometry so that we could choose the one with the highest transcriptional activity. Only the LNCaP cell line expressed PSMA positively with immunohistochemical stain. The PSMA promoter/enhancer had transcriptional activity in PSMA(1) cell lines and no activity in PSMA(2) cell lines. PSMAE-P achieved the strongest activity in different PSMA promoter/ enhancer combinations. We confirmed the specific expression of PSMA in prostate cells again. Similarly, transcriptional activity of the PSMA promoter/enhancer was prostate specific. PSMAE-P achieved the strongest transcriptional activity among PSMA promoter/ enhancer combinations, which could be used in advanced research for tissue-specific treatment.

Aims. Cytoprotective genes have shown to display potent anti-inflammatory and antiapoptotic functions in endothelial and smooth muscle cells. We investigated whether cytoprotective genes, especially A20, were involved in mycophenolate mofetil (MMF)’s ability to ameliorate transplant arteriosclerosis in an experimental chronic rejection model. Methods. Sprague-Dawley rat renal grafts were orthotopically transplanted into Wistar rats following the procedure of Kamada with our modification. The recipients were divided into three oral treatment groups: (1) vehicle group (cyclosporine [CsA] 10mg/kg•d×10d followed by vehicle), (2) CsA group (CsA 10mg/kg•d×10dd followed by CsA 6mg/kg • d), (3) MMF group (converted from CsA 10mg/kg•d×10d toMMF20mg/kg•d on day 11). At the same time points after transplantation, the rats were sacrificed to harvest the renal allografts. The expression of four cytoprotective genes, A20, heme oxygenase (HO)-1, Bcl-2, and Bcl-XL, was analyzed by quantitative reverse-transcriptase polymerase chain reaction and immunohistochemistry. Results. The four-cytoprotective genes were all detected in rat kidney allografts undergoing chronic allograft nephropathy. The expression of A20 in grafted kidneys was significantly higher in the MMF than in the CsA or the vehicle group (P<.01). There was no significant difference between the CsA and the MMF groups in the expression of HO-1, Bcl-2, and Bcl-XL. Conclusions. We demonstrated that MMF improved the expression of A20 in rat kidney allografts undergoing chronic allograft nephropathy. The correlation between MMF and A20 provide an explanation for the mechanism by which MMF ameliorates transplant arteriosclerosis in an experimental animal model of chronic rejection.