Objective To summarize the role of costimulatory molecules in inducing immune tolerance of organ transplantation. Methods Domestic and international publications online involving costimulatory molecules and immune tolerance in recent years were collected and reviewed. Results The relationship between costimulatory pathways and transplantation immunity has already been clarified in recent years. The main costimulatory molecules alreadly found mainly include B7-CD28/CTLA4, CD40-CD154, 4-1BB/4-1BBL, and ICOS-B7h, etc. Costimulatory pathways com-inhibition or combining with other immunosuppression methods could obtain stable and long lasting immune tolerance. Conclusions With the development of immunology and molecular biology, costimulatory pathways of T lymphocyte activation will be further interpreted. Other new costimulatory molecules will be discovered in the future, which will afford theory evidence for inducing immune tolerance.
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 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 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.
ObjectiveTo explore the influence of miRNA-155/PU.1 signaling pathway blockade on bone marrow-derived dendritic cells (DCs) maturation and immune function of rat small intestinal transplantation.
MethodsThe DCs were induced by adherent culture.The critical transcription factor gene PU.1 was designed and PU.1 siRNA was synthe-sized.The DCs were transfected by liposome transfection and a pair of PU.1 siRNA was screened according to the high silencing efficiency.The expressions of DCs surface markers CD80, CD86, and MHC-Ⅱamong three groups (PU.1 silent group, negative control group, and control group) were analyzed by flow cytometry.The IL-10 and IL-12p70 secretion levels in the supernatant were tested by ELISA method.The allogeneic T lymphocyte proliferation was tested by mixed lymphocyte reaction.The transfected cells were intravenously injected into the recipient rat on day 7 before intestinal transplantation.The survival conditions as well as pathological changes were observed in each group recipients.
Results①The surface molecules CD80, CD86, and MHC-Ⅱin the PU.1 silent group were (27.0±5.6)%, (23.6±4.8)%, and (36.8±6.8)%, respectively; versus (74.0±9.4)%, (76.5±8.7)%, and (87.8±11.3)% in the negative control group, respectively, which were significantly lower in former and showing an in creased trend (P < 0.05).②Compared with the negative control group, IL-10 secretion level was significantly increased (P < 0.05), IL-12p70 secretion level significantly decreased (P < 0.05) in the PU.1 silent group.③The proliferation of T lymphocytes in the PU.1 silent group was significantly lower than that in the negative control group (P < 0.05).④When the transfected DCs were injected into the intestinal transplantation rats on day 7 before operation, the survival time was (14.3±3.3) d, (7.8±1.5) d, and (8.0±2.5) d in the PU.1 silent group, negative control group, and control group, respectively, which in the PU.1 silent group were significantly longer than that in the other two groups (P < 0.05), and the graft pathology showed that there were mild intestinal tissue damage, lymphocyte infiltration or villus edema in the PU.1 silent group.
ConclusionmiRNA-155/PU.1 signaling pathway blockade could reduce DCs maturation and induce receptor-specific immune tolerance, which are proved both in vivo and in vitro.
Objective To explore the effect of cytotoxic T lymphocyte-associated antigen 4 (CTLA4-Ig) fusion protein on the function of orthotopic liver allograft. Methods Orthotopic liver allograft models of rhesus monkeys were established in this study. The survival time, liver function and morphologic changes of graft were observed, respectively. The levels of IL-2 and IL-10 were detected by ELISA. Apoptosis was monitored by TUNEL.Results The average survival of control group was 6.57 d, while the average survival of CTLA4-Ig group was 14.92 d, which was statistically prolonged (Plt;0.05). Serum ALT level was highly increased, and Alb level decreased obviously in control group. While the levels of ALT and Alb kept in normal in CTLA4-Ig group. After day 3-7, the expressions of IL-2 were highly expressed in control group, while the expressions of IL-10 in CTLA4-Ig group were higher than those of control group. The severity of rejection reaction after day 3 was weaker in CTLA4-Ig group than that of control group by histological assessment. The apoptosis index after day 3 in the liver cells was highly increased in control group as compared with the CTLA4-Ig group. Conclusions CTLA4-Ig fusion protein therapy can induce immunotolerance and prolong the survival of recipients. The increasing of cytokines IL-2 or the decreasing of cytokines IL-10 may be one of the laboratory indexes in monitoring immunotolerance of transplantation.
Objective To study the immunological tolerance induced by blocking the second signal of T cell with extrinsic cytotoxic T lymphocyteassociated antigen 4 immuno globlin(CTLA4-Ig). Methods Fifty-four BALB/C mice, inbred strains, were employed as recipients of bone allografts, using a model of heterotopic muscle pouch. The 54 mice were divided into 3 groups and18 for each group. The first group, in which the donor was C57BL/6 with intraperitoneal injection ofL6(as a control), was named AL group. The second group,also C57BL/6 with injection CTLA4-Ig, was named AC group. The third group,homologous BALB/C with injection of PBS buffer solution, was named AB group.The serum antibody, lymphocyte proliferation of the second stimulation by splenic cell and bone supernatant of donor, the analysis of lymphocyte subsets, a regraft experiment and histology were determined 2, 4 and 6 weeks after transplantation. The second transplantation was to regraft C57BL/6(BC group) and C3H(BHgroup) mice respectively after first 12 mice being transplantated with C57BL/6 and injected with CTLA4-Ig as to detect donor-specificity of immunological tolerance. Results Compared with AB group, AL group created more intensive immune rejection: CD4 T cell subsets(Plt;0.05), the serum antibody(Plt;0.05) and lymphocyteproliferation of the second stimulation by splenic cell and bone supernatant ofdonor (Plt;0.01 and 0.05) were significantly increased. However, the results of AC group showed that CTLA4-Ig significantly inhibited the immune rejection: CD4T cell subsets(Pgt;0.05), the serum antibody (Pgt;0.05), and lymphocyte proliferation of the second stimulation(Pgt;0.05) were similar to those of AB group. Histological observation of AC group showed that lymphocyte infiltration disappeared,cartilage and new bone formed, and bone marrow cavities emerged. A regraft experiment showed that CD4 T cell subsets (Plt;0.05) and lymphocyte proliferation of the second stimulation by splenic cell and bone supernatant of donor(Plt;0.05), BC group was significantly lower than those of BH group. So theimmunological tolerance induced by CTLA4-Ig was of donor-specificity. Conclusion The immunological tolerance induced by CTLA4-Ig was prolonged for 6 weeks. This study provides a brand-new path for bone transplantation, which can be helpful to other organ transplantation.
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.
Objective To observe the interferon-gamma; (IFN-gamma;), interleukin-2 (IL-2) levels of Th1 cytokine and IL-4、IL-10 levels of Th2 cytokine in serum and culture supernatants of splenic cells of the rats in the prevention of experimental autoimmune uveoretinitis（EAU）by oral tolerance. Methods 72 Lewis rats were randomly divided into EAU group，oral tolerance group (which including 10 mu;g、100 mu;g、1 mg、10 mg of S antigen group respectively) and control group，12 rats in each group. The animal model of EAU was induced by immunization with S antigen（50 mu;g）and Freundrsquo;s complete adjuvant. Oral tolerance 10 mu;g、100 mu;g、1 mg and 10 mg group were fed with 1 ml mixture of 10 mu;g、100 mu;g、1 mg、10 mg S antigen and 1 mg trypsin inhibitor respectively by intubation，once the other day，totally 7 times，and then induced EAU according to above methods；control group was fed with 1 ml mixture of phosphate buffered saline and 1 mg trypsin inhibitor，once the other day，totally 7 times，and then induced EAU. The clinical manifestation of EAU in the eye were recorded,the eyeballs were enucleated at the peak of EAU，followed by pathological grading. Meanwhile the serum was colleced; splentic cells were separated and cultured to collect the supernatant. Cytokine levels of IFN-gamma;, IL-2, IL-4 and IL-10 in serum, cultured supernatant of splenic cells were determined by enzyme-linked immunosorbent assay (ELISA). Results Compared with EAU and control group, the levels of IFN-gamma; and IL-2 (Th1 cytokine) in the serum in 100 mu;g and 1 mg group were decreased while the levels of IL4 and IL10 (Th2 cytokine) were increased，the differences were statistically significant（F=51.9, 68.8, 35.7,7.5,P＜0.01). Compared the levels of Th1 and Th2 cytokines in the serum in 10 mu;g, 10 mg group with EAU and control group, the differences were not statistically significant. In 100 mu;g、1 mg group, the levels of IFN-gamma; and IL-2 (Th1 cytokine) in the culture supernatant of splenic cells were decreased while the levels of IL-4 and IL-10 (Th2 cytokine) were increased, compared with EAU and control group, the differences were statistically significant（F=57.1,15.6,33.1,167.7, P＜0.01）. Compared the levels of Th1 and Th2 cytokine in the culture supernatant of splenic cells in 10 mu;g、10 mg groups with EAU and control group, the difference are not statistically significant. Conclusions In the process to prevent EAU by oral intake, the levels of IFN-gamma; and IL-2 (Th1 cytokine ) were decrease while the levels of IL-4 and IL-10 (Th2 cytokine). Oral administration with too high or low dose of the antigen can not prevent EAU as well as the cytokine levels do not change obviously. Cytokines has played an important role in the prevention of EAU.
