Objective To summarize the research progress of programmed cell death protein 1 (PD-1)/programmed cell death protein-ligand 1 (PD-L1) inhibitors before liver transplantation of liver cancer. Method The literatures on the application of PD-1/PD-L1 inhibitors before liver transplantation of liver cancer were collected and reviewed. Results PD-1/PD-L1 inhibitors preoperatively treated liver transplantation recipients had a low incidence of postoperative rejection, and routine usage of hormone and immune tolerance induction therapy in liver transplantation recipients might reduce the incidence of rejection caused by PD-1/PD-L1 inhibitors. Conclusion Preoperative usage of PD-1/PD-L1 inhibitors have more benefits than risks for patients with advanced liver cancer.
Objective To summarize the advancement of immune tolerance in pancreas transplantation.Methods Relevant literatures about immune tolerance in pancreas transplantation, which were published recently domestic and abroad were collected and reviewed. Results The main methods to induce immune tolerance are peripheral tolerance and central tolerance. The induction of chimerism by infusion of donor-specific bone marrow cells is the research hot spot recently. Conclusion The infusion of donor-specific bone marrow cells in combination with one or more peripheral tolerance maybe can induce immune tolerance successfully. However, it should be researched further.
Objective To study the effect of anti-CD40L monoclonal antibody on the rejection of rat pancreatic islet xenografts and its mechanism. Methods The animal models of human-rat pancreatic islet xenografts were established and were treated with anti-CD40L monoclonal antibody. The levels of blood glucose of transplantation rats were measured and the survival of grafts and transplantation rats were observed after transplantation. The morphological changes of grafts were observed and the levels of cytokines (IL-2 and TNF-α) were quantified by ELISA. Results ①Level of blood glucose in all the rats with diabetes decreased to normal on day (2.3±0.2) after transplantation. The average level blood glucose of control group began to increase on day (8.1±0.6), while the treatment group began to increase on day (18.5±1.2) after transplantation, which was significantly postponed compared with control respectively (P＜0.01). ②Grafts of treatment group and control group survived for (22±8.2) and (10±2.1) days respectively. Survival of grafts in treatment group was significant longer than that in control group (P＜0.01). ③Survival of transplantation rats were (35±6.5) and (21±5.7) days in treatment group and control group respectively. The survival of transplantation rats in treatment group was significant longer than that in control group (P＜0.05). ④Levels of serum IL-2 and TNF-α in control group increased dramatically within (3.2±0.3) days and reached peak within (7.3±0.5) days after transplantation, which were significantly higher than those measured before transplantation (P＜0.01); While in treatment group, the levels of serum IL-2 and TNF-α began to increase on day (22.6±1.7) after transplantation, and reached peak on day (28.5±2.2), which was significantly postponed than those in control group (P＜0.01). Conclusion Anti-CD40L monoclonal antibody can inhibit the rejection of rat pancreatic islet xenografts and prolong the survival time of transplantation rats and grafts.
Objective To investigate the expression of transcription factor Foxp3 in the orthotopic liver transplantation by using the inbred rats with spontaneous immune tolerance. Methods The model of orthotopic liver transplantation was established on inbred rats according to double-sleeve technique. The total RNA that was isolated from liver was reversely transcribed into cDNA. The method of real-time fluorescence quantitative PCR (RFQ-PCR) was used to analyze the expression level of Foxp3 mRNA in tolerance group and syngeneic group, respectively. The expression of Scurfin in hepatic tissue was assayed by Western blot and then was analyzed by computer imaging system. Results The expression levels of Foxp3 mRNA and Scurfin in the transplanted liver were significantly lower than those of normal liver within the first week after transplantation. The level of Foxp3 mRNA began to increase on day 7 and reached the peak point on day 14. The expression level of Foxp3 mRNA began to decrease on day 30 but was still higher than the normal value (P＜0.05). The Western blot showed resemble changes on that of Scurfin. Conclusion Transcription factor Foxp3 may play an important role in the spontaneous immune tolerance in the orthotopic liver transplantation of inbred rat.
Objective To study the role of chimerism on immune tolerance to cardiac allografts. Methods Male DA rat hearts were transplanted to male Lewis rats using Ono’s model and randomly divided into three groups: normal control group (group Ⅰ), rejection group (group Ⅱ), immune tolerance group (group Ⅲ). Mean survival time (MST), histological changes, mixed lymphocyte reaction (MLR), chimerism of recipients’ spleen and thymus were measured after operation. Results The MST of cardiac allografts in group Ⅲ (85.28±7.48 d) was significantly longer than that in the group Ⅱ (7.33±1.03 d). Only a few inflammatory cells infiltrated in cardiac allografts in group Ⅲ. MLR of group Ⅲ were significantly decreased compared with those of group Ⅰ (Plt;0.01). Conclusion The chimerism of recipient plays an important role on immune tolerance to cardiac allografts.
Objective To study the effect of allogeneic canine cord blood mesenchymal stem cells（cbMSC）transplantation on the distribution of CD4+T and CD8+T in infracted area of hearts. Methods Mononuclear cells of cord blood were isolated by density gradient centrifugation and amplified by adherent culture. 36 adult male dogs were divided into experimental group and control group. Animal models of acute myocardial infarction were established by ligating anterior descending coronary artery. The fourth generations of mesenchymal stem cells (MSC) were transplanted into infarcted area of hearts by left anterior descending coronary artery after 72h induced by 5-aza and transfected by LacZ. The survival of transplanted cells in hearts can be confirmed by βgal expression. CD4+T and CD8+T cells distributed in infarcted area were detected by immunohistochemical staining method. The ImagePlus 5.1 software was used to analyze the images. Results Cells transplanted into infarcted area could survive for a long time. 2, 4, 8 weeks after transplantation, the IOD of CD4+T in experimental group were 44.35±7.03, 19.29±4.11 and 20.27±3.51 respectively, and the CD4+T/CD8+T ratios were 0.63±0.12, 0.51±0.15 and 0.66±0.08. In control group, the IOD of CD4+T at 2, 4, 8 weeks after transplantation were 65.78±10.27, 28.02±2.59, 29.79±6.83, and the CD4+T/CD8+T ratios were 1.28±0.20, 1.34±0.09 and 1.50±0.16. The IOD of CD4+T and CD4+T/CD8+T ratio in experimental group were significantly lower than that in control group. In experimental group the IOD of CD8+T at 2, 4, 8 weeks after transplantation were 69.88±7.84 , 37.80±8.83 and 30.81±7.42, higher than that in control group which were 51.28±10.01, 20.87±4.50 and 19.91±2.87. Conclusion The preliminary results indicated that allogeneic cbMSC transplanted in infarcted area can escape from immune rejection, its mechanism may be associated withdecreasing the amount of CD4+T cells infiltrated in periphery of infarcted area and maintaining CD4+T/CD8+T ratios at a lower level.
Objective To observe the effect of transfer of immature mouse myeloid dendritic cells （DC） generated with low-dose granulocyte-macrophage colony-stimulating factor （GM-CSF） on cardiac allograft survival. Methods Mouse DC were generated with standard doses or low doses GM-CSF from bone marrow cells, the phenotype and functional properties of these DC were compared through fluorescence-activated cell sorting（FACS） analysis and mixed lymphocyte reaction（MLR）, 1. 0 × 106 DC generated with low doses GM-CSF were administered to the recipients 7 days before transplantation, and the cardiac allograft survival were observed. Results In contrast to DC generated with standard doses, DC generated with low doses were phenotypically immature DC （CD11c＋, CD80- , CD86- , MHCⅡlow）, and induced allogeneic T cell unresponsiveness, and administration of these DC to recipients prolonged cardiac allograft survival from 6.3±1.2 days to 14.3±1.9 days. Conclusions DC generated from mouse bone marrow progenitors in low doses of GM-CSF are phenotypically and functionally immature, and prolong cardiac allograft survival when they are administered 7 clays before transplantation.