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.
OBJECTIVE:To investigate the index of the rejection of lJle retinal pigment epithelium(RPE)cells transplantation. METHOD:Allogenic RPE transplantation on rahbits by transcleral technique, the changes of interleukin-2 (IL-2) activity in peripheral blood and the effect of immunoinhibitor (methylprednisonlone)were detected. RESLILTS:In the group of simple transplantation,the IL-2 activity in peripheral blood begin to rise in the first day after operation. The peak value occured in the third day,and is still much higher than that of the control group in the 14th day,whereas in the group treated with immunoinhibitor ,there was no obvious difference in the first day after operatlon,in the third day,the IL-2 activity rises slightly,and returned to normal level in the 7th day. CONCLUSION: After RPE transplantation, the level of IL-2 activity in peripheral blood might serve as an important index to determining and detecting the rejective response. （Chin J Ocul Fundus Dis,1996,12: 239-241）
ObjectiveTo compare the effect and safety of basiliximab in ABO incompatible pediatric liver transplant recipients.MethodsABO incompatible pediatric liver transplantation operated between January 2019 and August 2020 were studied. The patients were allocated randomized into two groups. Patients in experimental group were treated with basiliximab as immune induction therapy, but basiliximab was not used in patients of control group. Tacrolimus combined methylprednisolone were used after liver transplantation. The clinical characteristics, graft and recipient survival rate, rejection, infectious complications, and kidney functions after liver transplantation were observed. Donor specific antibody (DSA) was tested in 3 months after liver transplantation. The growth and development were assessed too after liver transplant.ResultsFourty-four patients were enrolled in the study, including 19 patients in the experimental group and 25 patients in the control group. The median follow-up time was 16.6 months (3.8–25.4 months), and there were no statistically differences between the two groups in terms of age, sex, weight, pediatric end-stage liver disease (PELD) score, and other basic conditions. There were no significant differences between the two groups in tacrolimus dose, tacrolimus trough concentration, kidney functions, height and weight growth after liver transplantation. There were no statistical differences in lung infection, blood stream infection within 3 months after liver transplantation, cytomegalovirus, EBV infection, graft/patient survival rate after liver transplantation (P>0.05). However, the acute rejection rate was lower and the DSA positive rate in 3 months after liver transplantation was lower in the experimental group (P<0.05).ConclusionsBasiliximab can be safely used in ABO incompatible pediatric liver transplant recipients. Acute rejection rate and DSA positive rate after transplantation can be decreased with the useof basiliximab.
Objective To observe the effects of Thymosin α1 （Tα1） on acute rejection after liver transplantation and immune function of T cells. Methods Twenty recipients of liver transplantation due to primary hepatic carcinoma were divided into two groups: Tα1 group (n=10) and control group (n=10). Tα1 group received subcutaneous injection of Tα1 1.6 mg on the first day after liver transplantation and then twice a week for at least one month. Both Tα1 group and control group took same immunodepressants. Core biopsies were carried to compare the incidence rate of acute rejection between Tα1 group and control group. Peripheral T cellular immune function in these two groups was detected on 1 d before, 1 week, 2 weeks and 1 month after transplantation. Results There was not significant difference of incidence rate of acute rejection between Tα1 group and control group (Pgt;0.05). In the Tα1 group, CD4+, CD8+ lymphocyte cell counts and the CD4+/CD8+ ratio were significantly higher than those in the control group in 2 weeks and 1 month after transplantation (P＜0.05). Conclusion Use of Tα1 in recipients who also takes rountine immunosuppressants dose not increase the risk of occurring acute rejection after liver transplantation. Tα1 can significantly increase CD4+, CD8+ counts and CD4+/CD8+ ratio, which shows that Tα1 may improve recipients’ cellular immune function.
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: In the guinea pig-to-rat cardiac xenotransplantation model, the effect of complement depletion by using Chinese Cobra Venom Factor(CVF) on hyperacute rejection was evaluated. METHODS: Cardiac xenograft from guinea pig was transplanted into the abdomen of rat after the recipient being given i.p. a dose of CVF 0.20 microgram/g. the recipients were divided into group A (control group), group B (only given CVF), group C (CVF + Cytoxan + Splenectomy), group D (Cytoxan + Splenectomy) Cytoxan was injected into the abdominal cavity with a dose of 60 mg/Kg. The survival time of xenograft was measured and histologic observation was carried out after the cardiac arrest. RESULTS: The survival time of xenograft ranged from 15 to 3,120 minutes. There were significant difference among group A compared with group B and C (P lt; 0.01), and no difference between group A and group D, as well as group B and C (P gt; 0.05). There were significant difference between group B and D, as well as group C and D(P lt; 0.01). The histologic observation proved that the hyperacute rejection in group A and D was milder than group B and C. CONCLUSION: The study reveals that CVF can prolong the xenograft time by depleting complement activities and restricting hyperacute rejection in this model. Further basic and clinical study of effect of CVF in xenograft transplantation is worthwhile.
Objective To investigate the effect of human placental-derived mesenchymal stem cells (PMSCs) on immunological rejection in mouse allogeneic skin transplantation. Methods The placenta fetal tissues from voluntary donors were used to isolate and culture the PMSCs, and the 3rd passage PMSCs were used in the experiment. Thirty Vr ∶ CD1 (ICR) mice at age of 1-2 days were used as skin donors for allogeneic skin transplantation. Thirty C57BL/6 mice at age of 6-8 weeks as recipients were made back skin defect of 12 mm in diameter and were randomly divided into 3 groups (n=10): group A, autograft; group B, allogeneic graft + PBS tail vein injection; and group C, allogeneic graft + human PMSCs (1 × 105 cells/mouse) tail vein injection. The flap survival was observed. At 7 days after skin transplantation, blood leukocyte counting, abdominal fluid macrophage activation, and the expression levels of interleukin 4 (IL-4), interleukin 17 (IL-17), and interferon γ (INF-γ) in blood and spleen were detected by ELISA and RT-PCR, respectively. Results The flap survival time was significantly longer in group A [(58.33 ± 4.04) days] than in groups B and C [(3.80 ± 0.92) days and (6.80 ± 0.82) days] (P lt; 0.05), and in group C than in group B (P lt; 0.05). At 7 days after transplantation, the blood leukocyte number was (6.32 ± 0.45) × 109/L in group A, (7.45 ± 0.52) × 109/L in group B, and (6.35 ± 0.39)× 109/ L in group C, and it was significantly more in group B than in groups A and C (P lt; 0.05). The macrophage activation rate of the abdominal fluid was 6.87% ± 2.40% in group A, 7.84% ± 0.44% in group B, and 15.98% ± 2.87% in group C; group C was significantly higher than groups A and B (P lt; 0.01). ELISA results showed that there was no significant difference in the concentrations of IL-4 among 3 groups (P gt; 0.05). Compared with group B, the concentrations of IL-17 and IFN-γ were significantly reduced in group C (P lt; 0.05), while the concentration of IFN-γ was significantly increased in group B when compared with group A (P lt; 0.05). RT-PCR results showed that there were significant differences in the expressions of IL-4, IL-17, and IFN-γ mRNA between groups B, C and group A (P lt; 0.05); the expressions of IL-4 and IFN-γ mRNA were significantly lower in group C than in group B (P lt; 0.05). Conclusion Human PMSCs transplantation can suppress the acute immunological rejection in allogeneic skin transplantation. The possible mechanism may be partially related to the inhibitory effect on the secretion of IL-17 and IFN-γ.
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.
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.
Objective To study the effect of Huaier granule on the recurrence and metastasis of hepatocellular carcinoma (HCC) and immune rejection in the postoperative patients with liver transplantation for HCC. Methods Twenty-eight patients of liver transplantation for HCC who had taken Huaier granule orally for more than 6 months from September 2001 to March 2007 in West China Hospital were included as treatment group, and other 56 patients of liver transplantation for HCC who didn’t take any Huaier granule in the same time were included as the control group according to the same stage of TNM, degree of tumor differentiation (Edmondson grading) respectively with the treatment group. The method of retrospective cohort study was used to compare the incidence of immune rejection and the 6-month, 1-year, and 2-year recurrence and metastasis of HCC, disease free survival rate, and survival rate between two groups after 2 years’ follow-up beginning from the date of surgery. Results The 6-month, 1-year, and 2-year tumor recurrence and metastasis incidences in treatment group were 14.3%, 32.1%, and 39.3% respectively, which were 23.2%, 32.1%, and 50.0% respectively in control group, and the 2-year tumor recurrence and metastasis incidence of the treatment group was lower than that of the control group. The 6-month, 1-year, and 2-year disease free survival rates in treatment group were 85.7%, 67.5%, and 60.0% respectively, which were 76.7%, 67.6%, and 49.3% respectively in control group, and the 2-year disease free survival rate of treatment group was higher than that of the control group. The 6-month, 1-year, 2-year survival rates in treatment group were 92.9%, 78.6%, and 67.9% respectively, which were 89.3%, 75.0%, and 62.5% respectively in control group. But the 2-year tumor recurrence and metastasis incidence (P=0.353), 2-year disease free survival curve (P=0.386), and 2-year survival curve (P=0.620) were not significantly different between two groups. The incidence of immune rejection was 14.29% in the treatment group and 16.07% in the control group, which was not significantly different between the two groups (P=0.831). Conclusions Huaier granule can increase the 2-year tumor-free survival rate and restrain the recurrence and metastasis of HCC, and does not increase the incidence of immune rejection. Huaier granule as a treatment of HCC in patients with liver transplantation is safe and effective.