OBJECTIVE: To observe the heart anatomic and histological structure of the Banna mini-pig inbred-lined and to provide the morphological data for heart xenotransplantation and breeding transgens pig. METHODS: Ten Banna mini-pigs (12-18 months old) were affused and fixed by common coratid artery. The heart were observed and measured by gross anatomy and histology. RESULTS: There were many similarities between the Banna pig heart and the human heart in anatomy and histology. However, the following differences were observed in the Banna pig heart: 1. Azygos vein directly drew into right atrium cordis. 2. The intercalated disk of cardiac muscle was less than that of human. 3. The Purkinje’s fibre was bigger than that of human. CONCLUSION: On the morphology and histology, the structure of Banna pig heart is similar to the heart of human being. It is possible that Banna minipig heart becomes organ donors for xenotransplantation.
Objective To review the methods of overcoming immunological rejection in xenotransplantation.Methods The strategies of overcoming immunological rejection in xenotransplantation were analyzed and summaried on the basis of an extensive review of the latest l iterature concerned. Results The research development of immunological rejection mechanism and molecular biological technique provided new approaches for overcoming immunological rejection in xenotransplantation. Conclusion It is only a matter of time for xenotransplantation to be appl ied cl inically.
Objective To investigate the immunological rejection after hepatocyte transplantation for acute liver failure （ALF） in mice．Methods The hepatocytes were isolated from pig，BALB/c and C57BL/6 mice livers were conducted and then transplanted into C57BL/6 mice．CCl4 was used to make ALF mice model．The experimental animals were randomly divided into three groups， including syngenic group，allogeneic group，and xenogenic group．The survival statuses of all the mice were recorded. The alteration of T lymphocyte subsets，immune globulin，and cytokine were determined．Results ①The survival ratio was 8/10，6/10， and 3/10 in the syngenic group， allogeneic group， and xenogenic group， respectively．The survival ratio in the syngenic group was significantly higher than that in the other two groups （P＜0.05）．②The CD4+ and CD8+ T cells of the peripheral blood in the syngenic group did not change significantly on week one after transplantation．The CD4+ T cells in the allogeneic group reached the peak on day 3 after hepatocyte transplantation （P＜0.05）， while CD8+ T cells did not change much in one week．The CD4+ and CD8+ T cells in the xenogenic group increased and reached the peak on day 3 after transplantation （P＜0.05）．③There were no significantly differences of IgM and IgG in the syngenic group among 0.5， 1， and 3 d after transplantation. IgM of the allogeneic group and xenogenic group reached the peak on day 1 （P＜0.05） and IgG reached the peak on day 3 （P＜0.05） after transplantation．④The concentrations of IFN-γ， TNF-ɑ， and IL-2 in the allogeneic group and xenogenic group were significantly higher than those in the syngenic group （P＜0.05）．The concentration of IL-6 of the xenogenic group was higher than that of the other two groups （P＜0.05）. Conclusions CD4+ and CD8+ T cells play an important role in immune response to both allogeneic and xenogenic hepatocyte transplantation， as well as induce humoral immune response early after hepatocyte transplantation．
OBJECTIVE The major obstacle in pig to human transplantation is acute and hyperacute rejection (HAR) triggered mainly by alpha-galactosyl residues(alpha-Gal) in donor. Since the inbred-line Banna pig(IBNP) and Wuzhishan pig (IWZSP) are highly inbred and may be the potential donor for xenotransplantation, it is important to investigate the reaction between human serum and inbred-line pig tissues as well as the distribution of alpha-Gal in these tissues. METHODS Samples from heart, liver, spleen, lung, kidney, pancreas, small intestine, thymus, skin, lymph node and blood vessels at all levels were collected from four 8 to 11-month-old male IBNPs and one IWZSP. Affinity-immunohistochemistry assays were conducted following routine procedures on paraffin sections with normal human sera of blood type A, B, O, AB and BSI-B4(alpha-Gal specific binding lectin) as the primary antibodies or affinity reagents. Sections digested by alpha-galactosidase were also examined as control. RESULTS Parallel results were obtained from these pig tissues stained against human sera and BSI-B4. There was no significant difference both in the antigens recognized by sera of different blood types or BSI-B4 and in the distribution of alpha-Gal. The best alpha-Gal positive staining was appeared in vascular endothelial cells at all levels and partial parenchyma cells. However, tissues of cartilage, peripheral nerve and muscle were negative. After digested by alpha-Galactosidase, all samples were negative against BSI-B4 and human sera except few positions that showed different staining. CONCLUSION The distribution of target antigen is similar in various tissues of the two kinds of pigs. Though alpha-Gal is the major xenoantigen in IBNP and IWZSP, there may be some unknown antigens related to pig to human transplantation. Possibly the level and distribution of antigen expression in pig tissues are not the first affair to be considered, and these pigs should be genetically modified in order to eliminate rejection in pig to human xenotransplantation.
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 evaluate the general situation of the native pig breeds and the relative present study conditions for better development of xenotransplantation in China. METHODS By comparing the profits between the pigs and the non-human primates as the potential donors for xenotransplantation and emphasizing the source of the pigs as the organ donors from the transplantation studies, we analyzed the possible values of the native pig breeds as the donors. RESULTS As one of the richest resources in the world, the species variation and relative genetic stability of Chinese native pig breeds could be the very valuable resources for xenotransplantation study and utilization. As a reverse, the xenotransplantation could provide opportunity for more economically and environmentally utilization of the pigs besides as the meat supply. CONCLUSION As a very valuable and potential resource of organ donor, the native pig breeds of China might be noticed by the xenotransplantation colleagues in the world. It is necessary, to keep the balance among the risk vs. benefit and the protection vs. utilization of this valuable resource.
OBJECTIVE: To investigate the role of direct and indirect recognition in pig-to-man xenotransplantation. METHODS: Taken the peripheral blood lymphocytes (PBLC) from three Neijiang pigs and two humans as stimulators and respondors, the one-way mixed lymphatic reactions (MLR) of xenograft were carried out, and allo- and self-PBLC as control. RESULTS: Among the three patterns of MLR, syngeneic was MLR the lowest in proliferation, the allogenic MLR was the highest, and the xenogenic MLR was medium. The PBLCs from humans and pigs were matched on HLA-A, B, DR and DQ by means of modified Terasaki assay. The match on pigs was failure because of the pre-existing natural xenogenic antibody in the testing serum. CONCLUSION: The results suggest that the degree of MHC matching still affect the rejection in xenotransplantation, but the present serum assay of MHC matching is not fit for pig.
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 improve the Heron’s technique for heterotopic cardiac transplantation in rats by cuff vessel anastomosis in some aspectsand successfully establish the simplified model of cervical cardiac xenotransplantation from guinea pigs donor to SD rats recipients. Methods The donors were 64 male guinea pigs, whose weight ranged from 250 to 350 g； the recipients were 64 male SD rats, whose weight ranged from 300 to 350 g.The guinea pigs donor’s ascending aorta and pulmonary artery were anastomosed to SD rats recipient’s right common carotid artery and external jugular vein respectively with a self-made “sleeve” anastomosis. The modified cuff technique of heterotopic grafting is described in detail. Results 64 consecutive successful transplantations have been performed by single surgeon were done with negligible operative risk. No anastomosis leakage nor vessel obstruction. The total time of surgical procedure were 45 to 60 minutes. The new technique allowed vascular anastomoses to be completed in 2 to 5 minutes. The total cold ischemia time for donor heart was 14 minutes in average. Conclusion This modified Heron’s technique was a simple, economical, practicable,reliable and high reproducible model can be operated by surgeons with minimal training in microvascular surgery, and be applied to various transplantation immunological studies.
OBJECTIVE To detect the immunoreaction after osteoblast xenotransplantation and to investigate the possibility of heterogenic osteocyte transplantation and tissue engineered bone reconstruction. METHODS: Rat osteoblasts were isolated by two-part bony digestion/elements in culturing, and incubated in vitro at 37 degrees C, 5% carbon dioxide for 5 days until they multiplied and formed a monolayer on the bottom of dish. Twenty-eight rabbits were divided into 3 groups. Autograft of osteoblasts(group A), xenograft of osteoblasts(group B) and normal saline(group C) were implanted into the rectus abdominus muscle. The immunological and histological observations were performed after 1, 2, 4 and 8 weeks of transplantation. RESULTS: Cultured cells reached confluence within 5 days and was identified as osteoblasts by ALP staining and Bon kossa staining. The result of host versus graft reaction was negative. In group B, specific antibody reaction was detected 2 weeks and 4 weeks after transplantation. Cell mediated cytotoxicity was detected after 2 weeks, reached the peak value 4 weeks later, and then began to decline 8 weeks later. HE staining showed mass inflammatory cells and no ectopic ossification after 8 weeks. CONCLUSION: Heterogenic osteoblast transplantation will lead to an obvious change in host humoral and cellular immunity and lost the ability of bone formation. So, it can not be used for the reliable cell sources for osteocyte transplantation or tissue-engineering bone reconstruction.