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 construct the rhesus monkey Schwann cells (SCs) modified with human glial cell derived neurotrophic factor (hGDNF) gene. Methods The coding sequence of hGDNF amplified by PCR from pUC19-hGDNF was inserted into eukaryotic expression vector pBABE-puro. The recombinant eukaryotic expression vector pBABE-puro-hGDNF was identified with restriction enzyme digestion and DNA sequencing. The SCs were isolated from rhesus monkeys, cultured and purified. The SCs were transfected with the recombinant retrovirus vector containing hGDNF gene. The mRNA and protein expressions of hGDNF were analyzed by real-time fluorescent quantitative PCR and Western blot. Results The PCR product of hGDNF coding sequence was a 596 bp specific segment. The recombinant eukaryotic expression vector was digested into a 596 bp specific segment by specific restriction enzyme and another segment. The 596 bp segment confirmed by DNA sequencing was consistent with hGDNF sequence on GenBank. Restriction enzyme digestion and sequencing results showed that the coding sequence of hGDNF was successfully inserted into the recombinant retrovirus vector and the mRNA and protein expressions of hGDNF were significantly higher in transfected SCs than non-transfected SCs (P lt; 0.05). Conclusion The rhesus monkey SCs modified with hGDNF gene are successfully constructed and hGDNF can be released continuously and stably, which will provide a foundation for the further research about cell therapy of hGDNF-SCs in the repair of injured nerve.
Objective To study the protective effects of bone marrow mesenchymal stem cells (BMSCs) of rhesus monkeys on porcine islets from hypoxia/reoxygenation (H/R)-induced injury. Methods BMSCs were isolated and cultured from the marrow of 5 adult rhesus monkeys (weighing, 6-10 kg) by adherent monocytes. Islets were isolated and purified from the pancreas of 5 neonatal porcine (3-5 days old) by collagenase V digestion method, and were cultured with or without BMSCs, and exposed to hypoxia (1%O2) for 12 hours and reoxygenation for 24 or 48 hours, respectively. The experiment was divided into 4 groups: normal islet group (group A), normal islet + BMSCs group (Group B), H/R islet group (group C), and H/R islet + BMSCs group (group D). The survival rate of islets was calculated by fluorescein diacetate/propidium iodide (PI) staining. The viability of the islet cells was detected by cell counting kit 8. Apoptotic rate of islet cells was tested using Annexin V-FITC/PI labeling and flow cytometry. The stimulation index (SI) of islet function was analyzed by glucose-stimulated insulin secretion assay. Results The islet cell cluster of group C was more dispersed than that of groups A and B, and group C had more death cells; and the islet cell cluster of group D was more complete and the survival rate was higher than those of group C. The survival rate of islet was 90.2% ± 9.1%, 88.3% ± 5.9%, 52.3% ± 12.1%, and 71.4% ± 11.5% in groups A, B, C, and D respectively, it was significantly lower in groups C and D than in groups A and B (P lt; 0.05), but it was significantly higher in group D than in group C (P lt; 0.05). After coculture of BMSCs and islet at the ratio of 1 ∶ 10 and 1 ∶ 20 in group D, the viability of islet cells was significantly higher than that in group C (P lt; 0.05). The apoptotic rate was 27.1% ± 3.2%, 24.0% ± 1.0%, 64.3% ± 1.8%, and 46.2% ± 1.4% in groups A, B, C, and D respectively, it was significantly higher in groups C and D than that in groups A and B (P lt; 0.05), but it was significantly lower in group D than in group C (P lt; 0.05). There was no significant difference in SI between groups A and B at each time point (P gt; 0.05), but it was significantly lower in group C than in groups A and B (P lt; 0.05); and it was significantly higher in group D than in group C at 24 and 72 hours (P lt; 0.05). Conclusion BMSCs of rhesus monkeys can protect islet vitality and function from H/R-induced injury.
Objective To establish a method to isolate the CD4+CD25+ regulatory T cells (Tregs) and to identify the purity and function of these cells. Methods The peripheral blood (8 mL) were collected from the great saphenous vein of 10 rhesus monkeys (4 females and 6 males, aged 4-5 years, and weighing 5-8 kg). The mononuclear cells were isolated with density gradient centrifugation. CD4+ T cells were separated by the Magnetic cell sorting (MACS) negative selection and MACS positive selection. The cell yield rate, the cell viability, and the cell purity were compared between MACS negative selection and MACS positive selection. In CD4+ MACS negative selection, the anti-biotin MicroBeads and biotin-antibody cocktai in CD4+CD25+ Tregs isolation kit non-human primate were used, and in MACS positive selection, the anti-APC MicroBeads in CD4+CD25+ Tregs isolation kit non-human primate and CD4-APC were used. The CD4+ T cells separated by positive selection were selected to obtain CD4+CD25 Tregs with CD25 MicroBeads. The purity, activity, the FoxP3 level, and the suppressive function to concanavalin A (ConA) activated autologous CD4+CD24- effective T cells (Teffs) of CD4+CD25+ Tregs were detected by flow cytometry. Results After CD4+ T cells were separated by MACS negative selection and MACS positive selection, the cell viabilities were all up to 95%, showing no significant difference (P gt; 0.05). The cell yield rate and purity of CD4+ T cells by positive selection were significantly higher than those of CD4+ T cells by negative selection (P lt; 0.05). CD4+CD25+ Tregs can be successfully isolated by MACS double positive selection. The classifying purity was 76.2% ± 8.6%; the cell activity was 93.3% ± 4.7%; and the level of FoxP3 was 74.2% ± 6.9%. The CD4+CD25+ Tregs had suppressive effect on ConA activated autologous CD4+CD25- Teffs. Conclusion MACS double positive selection can be used to isolate high-purity CD4+CD25+ Tregs from the peripheral blood of rhesus monkeys and the process does not influence the activity of CD4+CD25+ Tregs.
Objective To observe the systemic and local immune response after repair of nerve defect with acellular nerve xenograft laden with allogenic adipose-derived stem cells (ADSCs) in rhesus monkey so as to evaluate the safety of the proposed material for nerve reconstruction. Methods Bilateral tibial nerves were taken from a healthy adult male landrace (weighing 48 kg) to prepare acellular nerve xenograft by chemical extraction. ADSCs were isolated from a healthy adult male rhesus monkey (weighing 4.5 kg), and were seeded into the acellular nerve grafts. The radial nerve defect models with 25 mm in length were established in 10 healthy adult female rhesus monkeys (weighing 3-5 kg), and they were divided into cell-laden group (n=5) and non-cell-laden group (n=5) randomly. Defect was repaired with acellular nerve xenograft laden with allogenic ADSCs in cell-laden group, with acellular nerve xenograft only in non-cell-laden group. The blood samples were taken from peripheral vein preoperatively and at 14, 60, and 90 days after operation for lymphocyte analysis; at 5 months after operation, the grafts were harvested to perform histological examination for local immune response and nerve regeneration. The nerve autograft in rhesus monkey was used as control. Results In cell-laden group and non-cell-laden group, no significant difference was found in the count of lymphocytes and T lymphocytes, the percentage of T lymphocytes, CD8+ T lymphocytes, as well as the ratio of CD4+ T lymphocytes to CD8+ T lymphocytes between pre- and post-operation (P gt; 0.05); in cell-laden group, the percentage of CD4+ T lymphocytes at 14 days was significantly lower than that at 60 and 90 days postoperatively (P lt; 0.05). The percentage of CD4+ T lymphocytes in cell-laden group was significantly lower than that in non-cell-laden group at 14 days (P lt; 0.05), but no significant difference was found in the other indexes at the other time between 2 groups (P gt; 0.05). At 5 months after operation, mild adhesion was found on the surface of nerve xenografts; the epineurium of nerve xenografts was thicker than that of nerve autografts; and neither necrosis nor fibrosis was found. CD3+, CD4+, CD8+, CD68+, and CD163+ T lymphocytes were scattered within the grafts, in which regenerative axons were revealed. CD3+, CD4+, CD8+, CD68+, and CD163+ T lymphocytes were comparable in cell-laden group, non-cell-laden group, and autograft group. Conclusion Repair of nerve defect with acellular nerve xenograft elicits neither systemic nor local immune response in rhesus monkeys. Implantation of allogenic ADSCs might result in transient depression of CD4+ T lymphocytes proliferation early after surgery, no immune response can be found.
OBJECTIVE: To construct tissue engineering bone with bio-derived materials and bone marrow stromal cells (MSCs), and to investigate the effect of allogeneic engineering bone implants on healing of segmental bone defects. METHODS: MSCs being aspirated aseptically from tibial tuberosities of young rhesus monkeys were induced into osteoblasts in vitro and then were cultured and marked with 5-bromo-2-deoxyuridine (BrdU). Tissue engineering bones were constructed with these labeled osteoblasts being seeded onto bio-derived materials made from fresh human bones which were treated physically and chemically, Then the constructs were implanted in 15 allogeneic monkeys to bridge 2.5 cm segmental bone defects of left radius as experimental groups, bio-derived materials only were implanted to bridge same size defects of right radius as control group. and, 2.5 cm segmental bone defects of both sides of radius were left empty in two rhesus monkeys as blank group. Every 3 monkeys were sacrificed in the 1st, 2nd, 3rd, 6th and 12th weeks postoperatively and both sides of the implants samples were examined macroscopically, histologicaly, and immunohistochemicaly. The two monkeys in blank group were sacrificed in the 12th week postoperatively. RESULTS: Apparent inflammatory reactions were seen around both sides of the implants samples in the 1st, 2nd, 3rd weeks, but it weakened in the 6th week and disappeared at the 12th week. The labeled osteoblasts existed at the 6th week but disappeared at the 12th week. The bone defects in experimental group were repaired and the new bone formed in multipoint way, and osteoid tissue, cartilage, woven bone and lamellar bone occurred earlier when compared with control group in which the bone defects were repaired in ’creep substitution’ way. The bone defects in blank group remained same size at the 12th week. CONCLUSIONS: Engineering bones constructed with bio-derived materials and MSCs were capable of repairing segmental bone defects in allogeneic monkeys beyond ’creep substitution’ way and making it healed earlier. Bio-derived materials being constituted with allogeneic MSCs may be a good option in construction of bone tissue engineering.
Objective To establish the swine to monkey auxiliary heterotopic liver transplantation model and to summarize surgical points. Methods Five healthy landrace piglets and five rhesus monkeys were adopted to establish the xenogenic auxiliary heterotopic liver transplantation model. In our trail landrace piglets were treated as donor andrhesus monkeys were treated as receptor. Putting the transplanted liver which included right posterior segment and part of right anterior segment into rhesus’ nest and left paracolic sulcus， and then blocking abdominal aorta and inferior vena cava shortly for end-to-side anastomosis in portal vein of transplanted liver and abdominal aorta of receptor， in infra-hepatic vena cava of transplanted liver and inferior vena cava of receptor. Ligation was performed at hepatic artery with no recon-struction. The postoperative situation and survival time of the receptors were observed. Results Four pairs of transplan-tation models were successfully established. The duration of donor liver harvesting， donor liver preparation， occlusion of recipient inferior vena cava， occlusion of abdominal aorta， and liver transplantation were （30±5） min （24-35 min），（40±10） min （31-51 min）， （30±6） min （23-36 min）， （30±8） min （22-38 min）， and （220±80） min （130-310 min）， respectively. The blood loss during transplantation was （42±6） mL （35-48 mL）. There were no thrombosis of the anas-tomosis and biliary fistula in receptors after operation， but 4 receptors died at 48， 54， 88， and 96 hours after liver transp-lantation respectively. Conclusions Swine to monkey auxiliary heterotopic liver transplantation model has b repea-tability， operation procedure is easy， and transplanted organ of it have good perfusion， which can be available for various kinds of basic and preclinical researches.
Objective To explore improvement of orthotopic liver transplantation model in rhesus monkey. Methods Healthy rhesus monkeys were chosen to perform orthotopic liver transplantation for 10 cases. The model was established by drawing on a variety of animal model methods, and the portal vein cuff method was used to establish stable model of orthotopic liver transplantation in rhesus monkeys. Results Ten orthotopic liver transplantation models in rhesus were performed, and the achievement ratio of operation was 10/10. The time of donor hepatectomy and donor preparation was (20±5) min and (30±7) min, respectively. The operation time of recipient and anhepatic phase were (180±35) min and (17±4) min, respectively. After 24 h of operation 9 cases survived, one case died of intra-abdominal hemorrhage after 9 h of operation. After 72 h of operation 8 cases survived, and one case died of upper gastrointestinal bleeding after 38 h of operation. After one week of operation 5 cases survived, and 3 cases died of rejection after 9, 11, and 11 d of operation, respectively. The longest survival time was 32 d, but all of them also died of rejection. No portal vein thrombosis and biliary complications were found in all recipients.Conclusion The improved rhesus monkey model of orthotopic liver transplantation is easy to perform with high achievement ratio of operation. It is an ideal animal model for pre-clinical studies of liver transplantation.
Human lymphocyte function-associated antigen 3 (hLFA3) has been identified as an important T cell accessory molecule. Rhesus monkeys (Macaca mulatta) have been widely used as animal models for human immune disorders. Due to the species-specificity of immune system, it is necessary to study M. mulatta LFA3 (mmLFA3). In this study, the gene encoding mmLFA3 CD2-binding domain (mmLFA3Sh) was amplified by polymerase chain reaction (PCR) and genetically fused to human IgG1 Fc fragment in pPIC9K to construct the expression plasmid pPIC9K-mmLFA3Sh-Ig. Approximately 3-4 mg mmLFA3Sh-Ig protein was recovered from 1 L of inductive media, and mmLFA3Sh-Ig produced by the P. pastoris can bind to the CD2 positive cells, and suppress the monkey and human lymphocytes proliferation induced by Con A and alloantigen in a dose-dependent manner. These results suggested that mmLFA3Sh-Ig might be used as a novel tool for pathogenesis and experimental immunotherapy of Rhesus monkey immune disorders.