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Petersen B, Carnwath JW, Niemann H. The perspectives for porcine-to-human xenografts. Comp Immunol Microbiol Infect Dis 2008; 32:91-105. [PMID: 18280567 DOI: 10.1016/j.cimid.2007.11.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2007] [Indexed: 10/22/2022]
Abstract
The shortage of donated human organs for transplantation continues to be a life threatening problem for patients suffering from complete organ failure. Although this gap is increasing due to the demographic changes in aging Western populations, it is generally accepted that international trading in human organ is not an ethical solution. Alternatives to the use of human organs for transplantation must be developed and these alternatives include stem cell therapy, artificial organs and organs from other species, i.e. xenografts. For practical reasons but most importantly because of its physiological similarity with humans, the pig is generally accepted as the species of choice for xenotransplantation. Nevertheless, before porcine organs can be used in human xenotransplantation, it is necessary to make a series of precise genetic modifications to the porcine genome, including the addition of genes for factors which suppress the rejection of transplanted porcine tissues and the inactivation or removal of undesirable genes which can only be accomplished at this time by targeted recombination and somatic nuclear transfer. This review will give an insight into the advances in transgenic manipulation and cloning in pigs--in the context of porcine-to-human xenotransplantation.
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Affiliation(s)
- Bjoern Petersen
- Institute of Farm Animal Genetics (FLI), Department of Biotechnology, Hoeltystrasse 10, 31535 Neustadt, Germany
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2
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Peptide mimetics of carbohydrate epitopes: strategies to block hyperacute rejection of porcine xenografts. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.7.11.1345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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3
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Dorling A. Strategies for preventing porcine xenograft rejection: recent progress and future developments. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.7.11.1307] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Malassagne B, Regimbeau JM, Taboit F, Troalen F, Chéreau C, Moiré N, Attal J, Batteux F, Conti F, Calmus Y, Houssin D, Boulard C, Houdebine LM, Weill B. Hypodermin A, a new inhibitor of human complement for the prevention of xenogeneic hyperacute rejection. Xenotransplantation 2003; 10:267-77. [PMID: 12694547 DOI: 10.1034/j.1399-3089.2003.02030.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Hyperacute rejection (HAR) of discordant xenografts in the pig-to-human combination can be prevented using tranplants expressing transgenic molecules that inhibit human complement. Hypodermin A (HA), a serine esterase that degrades C3, was tested in the guinea-pig-to-rat and in the pig-to-human combinations. METHODS Hypodermin A was tested in vitro, ex vivo, and in vivo models of HAR in the guinea-pig-to-rat combination. Hamster ovary cells (CHO) and a line of porcine aortic endothelial cells (PAEC11) were transfected with HA complementary DNA (cDNA). RESULTS The pattern of degradation of rat and human C3 by HA was different (multiple bands lower than 40 kDa) from the physiologic pattern observed after spontaneous degradation of rat C3 or physiologic activation of human C3. The CH50 activity in serum was significantly lower in rats treated with 3.2 mg HA/kg than in untreated rats (45 +/- 16 U/ml vs. 700 +/- 63 U/ml, P < 0.05). Sera from rats injected with 3.2 mg/kg of HA were less effective in lysing guinea-pig endothelial cells (12 +/- 7%) than normal rat sera (79 +/- 3%; P < 0.001). Ex vivo, guinea-pig hearts perfused by rat serum supplemented with HA survived longer than those perfused by non-treated serum (210 +/- 34 and 154 +/- 71 min, respectively; P < 0.05). In vivo, guinea-pig hearts transplanted into HA treated rats survived longer than in non-treated rats (27 +/- 5 min vs. 13 +/- 4 min; P < 0.001). In the presence of human serum, smaller amounts of C6 and C5b-9 were deposited onto HA-transfected CHO cells than onto control cells. The mHA-PAEC11 cells were significantly more resistant to lysis by human C than control PAEC11 cells. CONCLUSIONS These data suggest that transgenic HA could be used to prevent hyperacute xenogeneic rejection.
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Affiliation(s)
- B Malassagne
- Laboratoire d'Immunologie, AP-HP, Faculté Cochin, Université Paris V, Paris, France
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Saethre M, Sølvik UØ, Haraldsen G, Fiane AE, Boretti E, Thorsby E, Platt JL, Mollnes TE. Human serum-induced porcine endothelial cell E-selectin expression is associated with IgG3 and IgM anti-Gal antibodies. Xenotransplantation 2002; 9:350-8. [PMID: 12199866 DOI: 10.1034/j.1399-3089.2002.01094.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Naturally occurring anti-Galalpha1-3Gal (anti-Gal) antibodies and complement induce hyperacute rejection (HAR) of porcine organs transplanted to primates. If the hyperacute reaction is prevented, an acute vascular rejection (AVR) occurs within hours to few days. Antibodies are important for the development of AVR, whereas the role of complement is still not clarified. AVR is characterized by protein synthesis-dependent endothelial cell (EC) activation. In the present study we investigated the relation between EC activation as measured by E-selectin expression, and the concentrations of anti-Gal antibodies of IgM, IgG and IgG subclasses in sera from 80 healthy blood donors selected on the basis of sex and age. There was a significant correlation between E-selectin expression and the concentration of IgG3 anti-Gal (r=0.39; P=0.019), which was not seen for the other IgG subclasses or for total IgG anti-Gal. A modest, but significant correlation was found between the concentration of IgM anti-Gal and E-selectin expression (r=0.38; P=0.040), but not between IgM and IgG3 anti-Gal. There was a large interindividual variation in anti-Gal antibodies, 50-fold for IgM and 70-fold for IgG. Females had significantly higher concentrations of IgM anti-Gal than males (P=0.0006), which was explained by a substantial increase in IgM anti-Gal concentration in younger women. The concentration of IgG anti-Gal and the degree of E-selectin expression did not differ between sex or age groups. In conclusion, the close correlation between anti-Gal antibodies of the potent complement activating IgG3 subclass and porcine EC activation, may imply that these antibodies play a role in EC activation characteristic of AVR.
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Yokose S, Fukunaga S, Tayama E, Kato S, Aoyagi S. Histological and immunohistological study of cryopreserved aortic valve grafts: the possibility of a clinical application for cryopreserved aortic valve xenograft. Artif Organs 2002; 26:407-15. [PMID: 12000436 DOI: 10.1046/j.1525-1594.2002.06974.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The influence of preservation techniques on xenogeneic immune responses was examined to investigate the possibility of their clinical use. Mongrel dogs and pigs were used as allogeneic and discordant xenogeneic donors of aortic valve grafts, respectively. The allografts and xenografts were implanted in the abdominal aorta of mongrel dogs after cryopreservation or after fresh preservation. Allografts and xenografts were explanted at Days 7 and 42 for histological and immunohistochemical examination. In the fresh preserved allografts and the fresh preserved xenografts, the media of aortic wall grafts were significantly acellular at 7 days. Significant aortic medial destruction and neointimal proliferation with significant destruction of the valve leaflets was observed at 42 days. However, no differences were found among the preservation techniques in the xenogeneic grafts. To alleviate the lack of homografts, approaches such as the tissue-engineered graft may become an alternative in patients who are acceptable candidates.
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Affiliation(s)
- Shogo Yokose
- Department of Surgery, Kurume University School of Medicine, Kurume, Fukuoka-ken, Japan
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7
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Abstract
Xenotransplantation offers a potential solution to the shortfall in donor organs for human transplantation. This review describes the barriers to xenotransplantation and the progress that has been made towards making it a clinical reality. Data from preclinical pig-to-primate cardiac and pulmonary xenografts are highlighted.
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Affiliation(s)
- Karen M Dwyer
- Immunology Research Centre, St Vincent's Hospital, Melbourne, Victoria, Australia
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Régimbeau JM, Malassagne B, Taboit F, Boulard C, Houssin D, Weill B. [A new model of isolated perfused heart. Study of hypodermin A in hyperacute xenograft rejection]. ANNALES DE CHIRURGIE 2001; 126:1007-15. [PMID: 11803623 DOI: 10.1016/s0003-3944(01)00641-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIMS OF THE STUDY Isolated perfused heart (IPH) system and heart transplantation in the guinea-pig/rat combination represent a good model for the study of hyperacute xenograft rejection (HAR) in which the component plays a central role. Hypodermin A (HA), a protease cleaving the component, could be used to delay the HAR. METHODS Creation of an original IPH working with rat serum (30 mL) and ex vivo study of HAR and I'HA. RESULTS Study of HAR is possible with this IPH system. The mean guinea-pig heart survival after perfusion by normal rat serum was 38 +/- 7 min and was lower than survival observed after perfusion by guinea-pig serum (210 +/- 34 min) (p < 0.001), by decomplemented rat serum (177 +/- 45 min) (p < 0.001), and by rat serum with 20 micrograms/mL of HA (154 +/- 71 min) (p < 0.001). CONCLUSION We developed an original system of isolated perfused heart allowing ex vivo study of HAR. HA delayed the occurrence of the HAR and confirmed the central role of the component in the HAR.
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Affiliation(s)
- J M Régimbeau
- Laboratoire de recherche chirurgicale, AP-HP, faculté Cochin, université Paris V, France.
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Zhang Z, Bédard E, Luo Y, Wang H, Deng S, Kelvin D, Zhong R. Animal models in xenotransplantation. Expert Opin Investig Drugs 2000; 9:2051-68. [PMID: 11060792 DOI: 10.1517/13543784.9.9.2051] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The severe shortage of donor organs has provided a strong impetus to push the investigation into the use of animal organs for humans. Xenotransplantation will not only benefit patients, but also represents a unique and potentially profitable business opportunity. However, there are many barriers to successful clinical xenotransplantation, including immunological barriers, physiological incompatibility, zoonosis and ethical concerns. This overview will focus on currently available animal models used in attempts to break through the immunological barriers to xenotransplantation. There are many advantages to using small animal, namely rodent, models in xenotransplantation research. For example, the use of the mouse model allows the use of knockout mice and careful dissection of rejection mechanisms at the molecular level. The following models can be used to study hyperacute rejection (HAR): guinea-pig-to-rat, mouse-to-rabbit, guinea-pig-to-mouse, rat-to-presensitised mouse and rat-to-alpha-Gal knockout mouse. The hamster-to-rat, mouse-to-rat and rat-to-mouse models are commonly used to study acute vascular rejection. Large animal models are complex and expensive, but they are more relevant to clinical xenotransplantation. Based on experiments using transgenic pig-to-primate models, HAR can be overcome. However, acute vascular rejection remains a major barrier at the present time. A pig cartilage-to-monkey model has been developed to study chronic rejection. Other novel models such as pig venous segment-to-monkey model and rat-to-primate model may represent viable options to study immunological barriers following xenotransplantation. Like many other medical breakthroughs, animal research will continue to make enormous contributions towards the eventual success of xenotransplantation.
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Affiliation(s)
- Z Zhang
- London Health Sciences Center, University Campus, 339 Windermere Road, London, Ontario, N6A 5A5, Canada.
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Rayat GR, Rajotte RV, Ao Z, Korbutt GS. Microencapsulation of neonatal porcine islets: protection from human antibody/complement-mediated cytolysis in vitro and long-term reversal of diabetes in nude mice. Transplantation 2000; 69:1084-90. [PMID: 10762211 DOI: 10.1097/00007890-200003270-00011] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Recently, we have developed a simple and reliable method to efficiently isolate large numbers of neonatal porcine islets (NPI). We and others have shown that NPI are susceptible to cytolysis by the activation of human complement in vitro. Microencapsulation of islets may be one strategy to protect NPI from this form of rejection. We examined whether microencapsulation can prevent lysis of NPI induced by human antibody and complement in vitro and also assessed their ability to reverse hyperglycemia in diabetic nude mice. METHODS NPI were microencapsulated with purified alginate, cultured for 2 days, then tested for sensitivity to fresh human serum using an established in vitro cytotoxicity assay or transplanted into alloxan-induced diabetic nude mice. RESULTS Incubation of nonencapsulated NPI for 24 hr in the presence of fresh human serum resulted in a 53% loss of cellular insulin content, a 51% reduction in recoverable DNA content, and a marked reduction of insulin secretory responsiveness when compared with controls cultured in heat-inactivated human serum. In contrast, exposure of encapsulated islets to fresh human serum had no cytotoxic effect on the islets. Transplantation of 2000 encapsulated NPI i.p. into diabetic nude mice (n=16) corrected hyperglycemia in all mice within 8 weeks. Similar results were obtained when 2000 nonencapsulated NPI were implanted under the kidney capsule (n=10); however recipients of nonencapsulated NPI placed i.p. failed to obtain euglycemia and survived for only 3 weeks posttransplantation. CONCLUSION Microencapsulation protects NPI from the cytotoxic effects of human antibody and complement and allows for long-term reversal of diabetes in nude mice.
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Affiliation(s)
- G R Rayat
- Surgical-Medical Research Institute, Department of Surgery, University of Alberta, Edmonton, Canada
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Grimm H, Mages P, Lindemann G, Potthoff M, Bohnet U, Korom S, Ermert L. Evidence against a pivotal role of preformed antibodies in delayed rejection of a guinea pig-to-rat heart xenograft. J Thorac Cardiovasc Surg 2000; 119:477-87. [PMID: 10694606 DOI: 10.1016/s0022-5223(00)70126-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Whereas the involvement of elicited xenoantibodies in delayed xenograft rejection is currently being substantiated, this study focuses on the role of the preformed fraction of xenoantibodies. METHODS To check the influence of the latter, we combined pretransplant complement inactivation (cobra venom factor) and antibody reduction (plasmapheresis) in a guinea pig-to-rat heart transplant model. RESULTS Antibody reduction on plasmapheresis before xenografting did not prolong delayed xenorejection in decomplemented rats, although the immunohistologic pattern lacked the immunoglobulin deposits along endothelial walls found in xenografts of merely decomplemented recipients. Astonishingly, plasmapheresis, if carried out 2 days before transplantation, almost tripled xenograft survival, although preformed antibody levels were completely restored and even rebounding at the time of grafting. The pattern and number of infiltrating cells did not differ in dependence of the timing of plasmapheresis nor did the proliferative response of lymphocytes in the mixed lymphocyte reaction differ. However, plasmapheresis led to a retarded decrease of the mononuclear cell tumor necrosis factor alpha secretory potential, which correlated well with a diminished immunohistologic staining of tumor necrosis factor alpha secreted by graft-infiltrating mononuclear cells. CONCLUSION These findings argue against a pivotal role of preformed xenoantibodies in the pathomechanistic process of delayed xenograft rejection and challenge the therapeutic strategy to reduce preformed xenoantibody levels before xenotransplantation in complement-inactivated recipients.
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Affiliation(s)
- H Grimm
- Department of General and Thoracic Surgery and the Institute for Pathology, University of Giessen, Giessen, Germany.
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Schraa EO, Stockmann HB, Broekhuizen AJ, Scheringa M, Schuurman HJ, Marquet RL, IJzermans JN. IgG, but not IgM, mediates hyperacute rejection in hepatic xenografting. Xenotransplantation 1999; 6:110-6. [PMID: 10431787 DOI: 10.1034/j.1399-3089.1999.00010.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We reported previously that no classical features of hyperacute rejection (HAR) could be found in liver grafts in the guinea-pig (GP)-to-rat model and that recipients died shortly after transplantation of non-immunologic causes. Thus, the GP-to-rat model is not suitable for studying the mechanisms of discordant liver xenograft rejection. In the hamster to rat model, long-term survival of a liver graft is possible, but extremely low levels of xenoreactive natural antibodies are present. To mimic a discordant situation with pre-formed IgM and IgG antibodies, we sensitized rats 1 or 5 weeks before grafting. Specific anti-hamster IgM antibodies were found in recipients sensitized at week -1 but not week -5. Anti-hamster IgG was present in all recipients, albeit considerably higher in animals sensitized 5 weeks before grafting. In these two models, we examined the mechanism of HAR of liver grafts and compared this with heart xenografts. Control heart and liver grafts were rejected 4 and 7 days after transplantation respectively. Liver grafts in recipients sensitized at week -5 showed venous congestion and bleeding after reperfusion, indicating HAR, however this was not observed after sensitization at week -1. This surprising finding was confirmed by histology. Massive extravasation, edema, and acute liver cell degradation were noticed in grafts subjected to HAR. Liver grafts of recipients sensitized at week -1 showed only minimal changes. Heart grafts were rejected hyperacutely in both sensitization models. IgG antibodies could be detected on liver grafts in the group sensitized at week -5 but not in the group sensitized at week -1. Minimal IgM depositions were found on liver grafts of animals sensitized 1 week before grafting. Rejected heart grafts from similar sensitization groups showed identical antibody depositions; only IgM depositions were massive. Complement depositions were found in all groups. These results indicate that IgG, but not IgM, mediates HAR in hepatic xenografting. Such a predominance of IgG over IgM does not exist for heart grafts.
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Affiliation(s)
- E O Schraa
- Department of Surgery, Erasmus University Rotterdam, The Netherlands
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Baquerizo A, Mhoyan A, Kearns-Jonker M, Arnaout WS, Shackleton C, Busuttil RW, Demetriou AA, Cramer DV. Characterization of human xenoreactive antibodies in liver failure patients exposed to pig hepatocytes after bioartificial liver treatment: an ex vivo model of pig to human xenotransplantation. Transplantation 1999; 67:5-18. [PMID: 9921790 DOI: 10.1097/00007890-199901150-00003] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND There are limited experimental data on the nature of the humoral response elicited in humans against pig antigens. In this study, we have examined the xenoantibody (XAb) response in eight patients with acute liver failure exposed to pig hepatocytes after treatment with the bioartificial liver (BAL). METHODS Patients' plasma samples obtained before and after BAL treatment were tested for IgM and IgG XAbs, IgG subclasses, and XAb cytotoxicity, using enzyme-linked immunosorbent assay and flow-cytometric assays. The characterization of pig aortic endothelial cell (PAEC) surface xenoantigens was analyzed by immunoprecipitation. RESULTS We observed by day 10, a strong anti-pig IgG and IgM XAb response in patients undergoing two or more BAL treatments, with a significant increase in all the IgG subclasses; in contrast, XAb titers did not change if the patients received only one BAL treatment. The majority of the XAbs produced to porcine antigens were primarily specific for the alphaGal epitope. Both IgG and IgM XAbs were cytotoxic to PAECs, and the cytotoxic activity of IgG was associated with high levels of IgG1 and IgG3 subclasses, known to be efficient on complement activation. The characterization of porcine surface antigens demonstrated that IgM human XAbs, before and after BAL exposure, recognized xenoantigens on PAECs with similar molecular weights, suggesting that the same population of XAbs were present in the patients before and after exposure to pig antigens. CONCLUSIONS Repetitive exposure of humans to porcine antigens after BAL treatment, results in a strong IgG and IgM XAb responses that are primarily directed against the alphaGal epitope. These XAbs are cytotoxic to PAECs and the IgG toxicity correlates with high IgG1 and IgG3 levels. Our data also suggest that no new XAb specificity emerges after porcine exposure.
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Affiliation(s)
- A Baquerizo
- Center for Liver Diseases and Transplantation, Department of Surgery, Cedars Sinai Medical Center, Los Angeles, California 90048, USA
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Atia N, Camoin L, Duflos G, Malassagne B, Chéreau C, Filipponi F, Mahboub S, Batteux F, Conti F, Michalski JC, Houssin D, Calmus Y, Weill B. Human preformed IgG combining with membrane-bound porcine serotransferrin lyse porcine endothelial cells through antibody-dependent cellular cytotoxicity. Eur J Immunol 1998; 28:3917-28. [PMID: 9862328 DOI: 10.1002/(sici)1521-4141(199812)28:12<3917::aid-immu3917>3.0.co;2-m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Preformed antibodies are involved in xenograft rejection. The purpose of this work was to characterize porcine xenoantigens recognized by human preformed IgG (hpIgG), and to investigate the role of hpIgG in xenogeneic rejection. IgG eluted from porcine livers perfused with human plasma, human sera and total human IgG were immunoblotted on porcine aortic endothelial cell extracts. The amino acid sequence of a 76-kDa antigen constantly revealed was 100% homologous with porcine serotransferrin (psTf). hpIgG from human sera, human IgG1 and IgG2 and F(ab')2gamma specifically bound to psTf. Neutralization by psTf abolished that binding. Although alpha1,3-linked galactose residues (Gal(alpha)1,3Gal) is the dominant epitope recognized by preformed antibodies in the swine-to-human combination, the analysis of carbohydrate composition of psTf showed that the molecule was devoid of Gal(alpha)1,3Gal moieties and that preformed anti-psTf IgG bound to epitopes localized on the peptide core of the molecule. Purified human anti-psTf IgG antibodies were able to bind to psTf linked to its receptor on porcine endothelial cells, and to kill those cells through antibody-dependent cellular cytotoxicity.
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Affiliation(s)
- N Atia
- Laboratoire d'Immunologie, Faculté Cochin, Université Paris V, France
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Urbani L, Fabre M, Cardoso J, Lambin P, Devillier P, Soubrane O, Houssin D, Gautreau C. Predominant role of the Fab fragment in delaying hyperacute rejection in guinea pig-to-rat xenotransplantation. Transplantation 1998; 66:395-7. [PMID: 9721810 DOI: 10.1097/00007890-199808150-00018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Human intravenous immunoglobulin G delayed xenogeneic hyperacute rejection (HAR) in the guinea pig-to-rat combination. We investigated the respective roles of the Fc and Fab fragments of the IgG molecule in this inhibitory effect. METHODS By using a guinea pig-to-rat heart transplantation model, the efficiency of IgG, Fab, and Fc in prolonging the grafted heart's survival time (ST) was compared. RESULTS A dose-dependent increase in the ST was observed with Fab (r=0.74, P < 0.0001), IgG (r=0.57, P < 0.001), and Fc (r=0.51, P < 0.01). The linear regression slopes with Fab and with IgG were, respectively, sevenfold and fourfold steeper than with Fc. The ST was significantly longer than controls (23+/-7 min) after infusion of 2 g/kg IgG (147+/-42 min) or 1 g/kg Fab (176+/-38 min), whereas the highest dose of Fc (1.5 g/kg) did not induce significant prolongation of ST. In terms of equivalent functional doses, 1 g/kg Fab was significantly more potent in prolonging the ST than 1.5 g/kg IgG (87+/-25 min) or 0.5 g/kg Fc (33+/-14 min). Analysis of the rejected hearts evidenced edema, necrosis, and rat C3 deposits characteristic of HAR. CONCLUSION These results indicated that the delaying action of intravenous immunoglobulin G on HAR in the guinea pig-to-rat combination is mostly mediated through the Fab fragment.
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Affiliation(s)
- L Urbani
- Laboratoire de Recherche Chirurgicale, Faculté de Médecine Cochin-Port-Royal, Paris, France
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16
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Malassagne B, Taboit F, Conti F, Batteux F, Atia N, Chéreau C, Conjeaud H, Théron MC, Attal J, Braet F, Houdebine LM, Calmus Y, Houssin D, Weill B. A newly established porcine aortic endothelial cell line: characterization and application to the study of human-to-swine graft rejection. Exp Cell Res 1998; 238:90-100. [PMID: 9457060 DOI: 10.1006/excr.1997.3831] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The establishment of cell lines allows reproductible in vitro studies that would be far more difficult to perform using primary cells that rapidly undergo phenotypical alterations in culture. The purpose of this work was to establish an endothelial cell line appropriate for in vitro study of endothelial cell activation during xenograft rejection. Porcine aortic endothelial cells were transfected with the early region of SV40 and selected on the basis of morphological, phenotypical, and functional features. By light and electron microscopy, the porcine aortic endothelial cell line (PAEC11) and primary cells were similar except that PAEC11 was slightly smaller. PAEC11 displayed endothelial cell characteristics since it endocytosed acetylated low density lipoproteins, produced von Willebrand factor, and expressed E-selectin. Human natural antibodies bound to the same xenoantigens on PAEC11 and primary cells. That binding was followed by human complement activation and cell lysis. In addition, PAEC11 was found appropriate for genetic engineering since it could be transfected with a plasmid encoding a foreign gene. Therefore, this cell line should be a useful model for in vitro study of endothelial cell function in general and human-to-swine xenograft rejection in particular.
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Affiliation(s)
- B Malassagne
- Laboratoire de Recherche Chirurgicale, Faculté Cochin-Port Royal, Université Paris V, France
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17
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Allaire E, Bruneval P, Mandet C, Becquemin JP, Michel JB. The immunogenicity of the extracellular matrix in arterial xenografts. Surgery 1997; 122:73-81. [PMID: 9225918 DOI: 10.1016/s0039-6060(97)90267-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Determinants of xenograft immunogenicity are poorly characterized. We showed previously that decellularized arterial xenografts (DAXs) dilate, whereas decellularized arterial isografts (DAIs) and allografts do not, suggesting an interspecies, rather than an intraspecies, immunogenicity of the arterial extracellular matrix leading to chronic rejection. Now we have investigated the immunogenicity of the arterial extracellular matrix in xenografts and its impact on chronic injury (elastin lysis) and remodeling (graft dilation). METHODS Diameter and elastin content were measured in DAIs and DAXs from hamster to rat (concordant combination) and guinea pig to rat (discordant combinations) at 8 weeks. We also characterized the immune effectors infiltrating DAIs and DAXs by immunohistochemistry after 6 hours to 4 weeks of implantation. Results were compared with nondecellularized isografts and xenografts. Last, the impact of the donor-recipient phylogenetic distance on monocyte-macrophage penetration into the media was assessed in three xenograft combinations. RESULTS DAXs from guinea pig, but not from hamster, were aneurysmal at 8 weeks. Elastin lysis paralleled graft dilation. DAXs, but not DAIs, were infiltrated by monocytes, macrophages, T lymphocytes, and immunoglobulins. The donor-recipient combination did not affect the phenotype of the inflammatory infiltrate in DAXs, but it modified the kinetics of monocyte-macrophage penetration into the media. The absence of decellularization changed the inflammatory infiltrate phenotype (absence of macrophages) but had little impact on DAX injury and remodeling. CONCLUSIONS DAX immunogenicity accounts for most of chronic arterial xenograft injury, which is modulated by the donor-recipient combination. The immunogenicity of arterial xenografts, unlike allografts, is supported by the extracellular matrix in addition to the cells and could influence the long-term fate of xenografts.
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Affiliation(s)
- E Allaire
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unit 460, Centre Hospitalier Universitaire Xavier Bichat, Paris, France
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Romanella M, Aminian A, Adam WR, Pearse MJ, d'Apice AJ. Involvement of both the classical and alternate pathways of complement in an ex vivo model of xenograft rejection. Transplantation 1997; 63:1021-5. [PMID: 9112358 DOI: 10.1097/00007890-199704150-00020] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND It is now generally accepted that complement activation is critical for the hyperacute rejection of xenografts. Activation of the classical pathway as the result of the interaction of xenoreactive IgM xenoantibodies with the vascular endothelium has been observed in all species combinations examined to date. A number of studies using a variety of species combinations have also implicated alternate pathway involvement; however, these studies do not enable a conclusion to be drawn as to whether the alternate pathway can be activated in the complete absence of classical pathway activation. METHODS In this study, human plasma was depleted of both Clq and factor D and then reconstituted with purified Clq or factor D to restore the classical and alternate complement pathways, respectively. The ability of these modified plasmas to prosecute hyperacute rejection was then examined using an ex vivo isolated mouse heart perfusion model based on the Langendorff system. RESULTS AND CONCLUSIONS In the mouse to human species combination, both the classical and alternate pathways of complement are independently capable of initiating complement activation and mediating xenograft rejection.
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Affiliation(s)
- M Romanella
- Immunology Research Centre, St. Vincent's Hospital, Victoria, Australia
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19
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Baboon Liver Xenotransplantation in Humans: Clinical Experience and Principles Learned. Xenotransplantation 1997. [DOI: 10.1007/978-3-642-60572-7_58] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
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20
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Cattan P, Zhang B, Braet F, Atia N, Conti F, Conjeaud H, Weill B, Chereau C, Houssin D, Calmus Y. Comparison between aortic and sinusoidal liver endothelial cells as targets of hyperacute xenogeneic rejection in the pig to human combination. Transplantation 1996; 62:803-10. [PMID: 8824481 DOI: 10.1097/00007890-199609270-00018] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Endothelial cells of aortic origin are usually used in vitro as targets of hyperacute xenogeneic rejection, although endothelial cells from organs may have different properties. The sensitivities of aortic and liver endothelial cells to hyperacute xenogeneic rejection were compared in the pig to human combination. Sinusoidal liver endothelial cells were isolated and purified by collagenase perfusion of pig livers, sedimentation on a percoll gradient and selective adherence. Purity and viability of isolated liver endothelial cells after adherence were 85+/-6% and >95%, respectively. Endothelial cells from pig aortae (purity and viability >95%) were isolated by scraping. Immunoblotting analysis of xenoantigens on liver and aortic endothelial cell membranes preparations showed identical patterns. The strongest bands revealed by human IgM were located between 110 and 135 kD, while human IgG detected two major bands at 115 and 75kD. The membrane expression of xenoantigens recognized by human sera, analyzed by flow cytometry, was significantly lower on liver than on aortic endothelial cells (IgM: P=0.0006; IgG: P=0.0009). However, the complement-dependent cytotoxic activity of human sera was the same whether liver (54.5+/-1.4%) or aortic endothelial cells (50.0+/-4.2%) were used as targets. Taken together, those results allow the use of aortic instead of sinusoidal liver endothelial cells in the characterization of pig antigens recognized by human natural antibodies.
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Affiliation(s)
- P Cattan
- Laboratoire de Recherche Chiurgicale, Faculté de Médecine Cochin-Port-Royal, Université Paris V, France
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Allaire E, Mandet C, Bruneval P, Bensenane S, Becquemin JP, Michel JB. Cell and extracellular matrix rejection in arterial concordant and discordant xenografts in the rat. Transplantation 1996; 62:794-803. [PMID: 8824480 DOI: 10.1097/00007890-199609270-00017] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Vascularized xenografts are rejected acutely and hyperacutely in concordant or discordant combinations, respectively. We investigated the impact of the donor-recipient combination on the rejection of arterial xenografts, analyzing the cellular and extracellular matricial compartments. Aortic xenografts were performed in a concordant (hamster) and a discordant (guinea pig) combination with Lewis rat. Graft cells and immune effectors were characterized by immunohistochemistry after 15 min and up to 30 days postimplantation. Macroscopic and microscopic structure of the grafts was studied at 60 days. IgC in the concordant combination and C3, C5b9, and IgM in the discordant combination deposited on endothelial cells, acutely and hyperacutely, respectively. The same immune effectors deposited on medial smooth muscle cells, but later than on endothelial cells. In both combinations the medial extracellular matrix was covered by IgM and IgC and infiltrated by monocytes (90%) and T lymphocytes (10%), with elastinolysis in the vicinity of monocytes. However, elastin resorption in the media at day 60 differed in concordant and discordant xenografts(75+/-10% and 99+/-1%, respectively). Intimal thickening and aneurysm developed in concordant and discordant combinations, respectively. Unlike arterial allografts, arterial xenografts are not a homogeneous group. The donor-recipient combination determines the mechanism and the timing of graft cell rejection, as well as the magnitude of medial elastin injury. As a consequence, chronic graft remodeling differs in the two combinations.
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Affiliation(s)
- E Allaire
- Unit 367 INSERM and Unit 430, Paris, France
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22
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Hengster P, Lsnke R, Feichtinger J, Hechenleitner P, Mark W, Eberl T, Klima G, Huemer H, Daha M, Margreiter R. Mechanisms of hyperacute rejection of discordant liver xenograft. Xenotransplantation 1996. [DOI: 10.1111/j.1399-3089.1996.tb00144.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Druet P, Sheela R, Pelletier L. TH1 and TH2 lymphocytes in autoimmunity. ADVANCES IN NEPHROLOGY FROM THE NECKER HOSPITAL 1996; 25:217-41. [PMID: 8717628 DOI: 10.1111/j.1440-1797.1996.tb00091.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- P Druet
- INSERM U 28, Hôpital de Purpan, Toulouse, France
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24
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Parker W, Bruno D, Platt JL. Xenoreactive natural antibodies in the world of natural antibodies: typical or unique? Transpl Immunol 1995; 3:181-91. [PMID: 8581406 DOI: 10.1016/0966-3274(95)80024-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Xenoreactive natural antibodies are thought to be responsible for initiating the hyperacute rejection of porcine organs transplanted into primates. Progress has been made in recent years in the characterization of the specificity and functions of these antibodies. Xenoreactive natural antibodies recognize Gal alpha 1-3Gal, a carbohydrate related to the blood group A and blood group B antigens. The presence of Gal alpha 1-3Gal may not be sufficient to allow the binding of xenoreactive natural antibodies under physiological conditions; rather, the clustering of Gal alpha 1-3Gal determinants may dictate the extent to which xenoreactive natural antibodies attach to surfaces on which Gal alpha 1-3Gal is expressed. The predominant role of xenoreactive natural antibodies in the pathogenesis of hyperacute rejection in porcine-to-primate xenotransplantation involves the activation of complement. Complement activation is mediated by IgM, not IgG xenoreactive natural antibodies. Based on functional avidity, thermal binding optima, thermal liability and homogeneity of binding interactions, xenoreactive natural IgM appear to be members of a family of natural antibodies which includes isohaemagglutinins. The classification of xenoreactive antibodies and isohaemagglutinins into a family of antibodies may provide further insight into the nature and physiological functions of xenoreactive natural antibodies.
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Affiliation(s)
- W Parker
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA
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25
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Fujioka H, Cramer DV, Yasunaga C, Tuso PJ, Wu GD, Middleton Y, Moscioni AD, Rozga J, Demetriou AA, Makowka L. Differential patterns of reaction of human natural antibodies to pig hepatocytes and vascular endothelium. LIVER TRANSPLANTATION AND SURGERY : OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION FOR THE STUDY OF LIVER DISEASES AND THE INTERNATIONAL LIVER TRANSPLANTATION SOCIETY 1995; 1:85-93. [PMID: 9346546 DOI: 10.1002/lt.500010203] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have recently conducted a series of experiments to characterize the pattern of reaction of human natural antibodies (NA) with individual pig liver cells. Pooled normal human serum (PHS) was incubated with cultured pig hepatocytes (HEP), aortic endothelial cells (AEC), and portal endothelial cells (PEC), and the reaction of NA to different cell types was measured by antibody-mediated cytotoxic (MTT assay), antibody binding (ELISA), and flow cytometric analysis. The human NA displayed a differential pattern of binding with hepatocytes exhibiting a more limited expression of xenoantigen expression than either aortic or portal endothelial cells. These differences in reaction patterns were also noted for Western blot analysis of individual cell membrane extracts. Preincubation of the pig cells with anti-pig MHC antibodies did not inhibit the binding of human IgM natural antibodies to the pig cells. Comparison of the pattern of NA absorption following the use of bioartificial liver support in patients with acute hepatic failure demonstrated limited ability of pig hepatocytes to absorb substantial amounts of NA. These studies indicate that pig hepatocytes are less vulnerable to NA cytotoxicity than pig vascular endothelial cells and that pig vascular endothelial cells express xenoantigens that are unique and not found on hepatocytes.
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Affiliation(s)
- H Fujioka
- Department of Surgery, Cedars-Sinai Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Larkin DF, Williams KA. The host response in experimental corneal xenotransplantation. Eye (Lond) 1995; 9 ( Pt 2):254-60. [PMID: 7556727 DOI: 10.1038/eye.1995.49] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In addressing the worldwide shortage of human donor cornea for transplantation, animal cornea may be a substitute if mechanisms of xenogeneic (cross-species) rejection can be identified and controlled. Xenotransplantation of solid organs is followed by hyperacute rejection with minutes due to humoral graft rejection. In an experimental model corneal xenografts in rats survived for 2-3 days, depending on the phylogenetic disparity of the donor animal. Endothelial injury was the specific cause of graft failure, probably mediated by humoral rejection mechanisms. A later cell-mediated rejection response was seen. The potent humoral response is the most important feature differentiating xenograft from allograft rejection.
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Affiliation(s)
- D F Larkin
- Department of Ophthalmology, Flinders Medical Centre, Bedford Park, Australia
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Scares M, Beneden R, Havaux X, Werf W, Bach FH, Latinne D, Bazin H. Characterization of xenoreactive natural secreting cells in rats. Xenotransplantation 1994. [DOI: 10.1111/j.1399-3089.1994.tb00057.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Starzl TE, Valdivia LA, Murase N, Demetris AJ, Fontes P, Rao AS, Manez R, Marino IR, Todo S, Thomson AW. The biological basis of and strategies for clinical xenotransplantation. Immunol Rev 1994; 141:213-44. [PMID: 7868154 PMCID: PMC3005617 DOI: 10.1111/j.1600-065x.1994.tb00879.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Recent discoveries have suggested that the exchange of multiple leukocyte lineages between grafts and host and subsequent long-term chimerism in both is the seminal mechanism of the acceptance of organs transplanted from the same (allografts) or different species (xenografts). This insight suggests new strategies which may allow xenotransplantation, the principal obstacle to which has been humoral rejection. We have defined humoral rejection as a family of complement activation syndromes afflicting allografts and xenografts in which there is a strong (but not invariable) association with performed antigraft antibodies, invariable evidence of complement activation, histopathologic stigmas of vascular endothelial damage, and a concomitant local or systemic coagulopathy. The generic descriptive term hyperacute rejection is a misnomer because a slow-motion version of the same "humoral" process can occur with some allografts and is the rule with the so-called concordant species xenotransplantations. The pathway of experience and discovery leading to this conclusion shows clearly that the distinction frequently made between allograft versus xenograft humoral rejection does not actually exist in principle, but only in details and intensity. Breaking down this barrier to xenotransplantation, whether or not it is associated with antibodies, is unrealistic. However, the possibility of avoiding the barrier has been exposed by showing that animal organs can be humanized, with a mixed donor and recipient cell population similar to the chimerism seen in long surviving allografts or even with complete leukocyte replacement. Pilot experiments in rodents suggest that organs from fully xenogeneic chimeras can be made into xenogeneic targets that are no more provocative of complement activation than allografts when they are transplanted into the donor bone marrow species. Although the validity of this concept of organ xenograft preparation is only at the pilot stage of verification, there is reason to suspect that the complement trigger of humoral rejection can be thereby disarmed. If this can be accomplished, independent evidence suggests that cellular rejection can be controlled with conventional T-cell directed immunosuppression, perhaps even with surprising ease. The potential subtle liability of synthetic products of xenogeneic parenchymal cells is not yet known.
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Affiliation(s)
- T E Starzl
- Pittsburgh Transplantation Institute, University of Pittsburgh Medical Center, PA 15213
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Latinne D, Soares M, Havaux X, Cormont F, Lesnikoski B, Bach FH, Bazin H. Depletion of IgM xenoreactive natural antibodies by injection of anti-mu monoclonal antibodies. Immunol Rev 1994; 141:95-125. [PMID: 7868159 DOI: 10.1111/j.1600-065x.1994.tb00874.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
It is believed that IgM xenoreactive natural antibodies (XNA) and activation of complement are the two main effectors involved in the hyperacute rejection (HAR) of discordant xenografts, such as pig-to-primate kidney, liver or heart transplants. We have hypothesized that long-term depletion of circulating IgM XNA might be able to overcome HAR and induce the "accommodation" of pig-to-primate vascular discordant xenografts. Several techniques have been described to eliminate circulating XNA in primates but, up to now, none has been able to totally deplete these antibodies for a sufficiently long period of time in order to test the hypothesis of discordant xenograft "accommodation". Previous reports from our laboratory have shown that, in rodents, B-cell immunosuppression could be achieved by neonatal administration of anti-mu antibodies. Recently we have shown that administration of an anti-mu mAb, in adult rats, was able to totally deplete circulating IgM and IgM XNA, without immune complex disease. Furthermore, we have used different methods such as splenectomy, plasma exchange and an anti-B cell immunosuppressive agent mycophenylate mophetil (RS61443, Syntex, Palo Alto, USA) to pre-deplete circulating IgM before administration of anti-mu mAb (MARM-7) and showed that the effectiveness of anti-mu mAb to deplete circulating IgM was increased by 100-fold. Depletion of circulating IgM in adult rats by anti-mu mAb (MARM-7) was used as an experimental model to study the role of IgM XNA in the pathogenesis of HAR in guinea pig-to-rat cardiac xenografts. Our data show that IgM XNA play a major role in HAR, even if in this discordant combination direct activation of complement, probably through the alternative pathway, seems to be the main effector involved in HAR. We have analyzed the mechanisms of anti-mu depletion of circulating IgM in adult animals and shown that, besides anti-mu/IgM immune complex formation, depletion of circulating IgM results from the very significant inhibition of B-cell differentiation and secretion of IgM following in vivo crosslinking and internalization of surface IgM on B cells. As well, we provide evidence demonstrating that anti-mu mAb blocks B cells at an early stage of maturation, probably in the bone marrow. Furthermore, we have developed several rat anti-human and anti-baboon IgM mAb and tested their ability to deplete circulating IgM and IgM XNA in baboons, after splenectomy or splenectomy and plasma exchange.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- D Latinne
- Experimental Immunology Unit, Faculty of Medicine, University of Louvain, Brussels, Belgium
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Fox IJ, Sindhi R, Shaw BW. Xenografts: do they have a role? BAILLIERE'S CLINICAL GASTROENTEROLOGY 1994; 8:441-54. [PMID: 8000092 DOI: 10.1016/0950-3528(94)90030-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- I J Fox
- University of Nebraska Medical Center, Omaha 68198-3280
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Reding R, Soares M, Baranski A, Nisol F, Tomasi JP, Jamart J, Barker A, Latinne D, Lambotte L, Bazin H. Preformed antibody and complement rebound after plasma exchange: analysis of immunoglobulin isotypes and effect of splenectomy. Transpl Immunol 1994; 2:231-7. [PMID: 8000852 DOI: 10.1016/0966-3274(94)90065-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
UNLABELLED Splenectomy (Sx) has been proposed to attenuate post-PE (plasma exchange) rebound of isoagglutinins and xenogenic (XG) antibody (Ab) in both ABO-incompatible allografts and discordant xenografts. This study analyses the qualitative nature and kinetics of serum immunoglobulins as well as complement resynthesis after PE in sham-operated (PE) and splenectomized (PE+Sx) syngeneic LOU/C rats; non-PE sham-operated or splenectomized animals were used as controls. PE was performed in unanesthetized, unheparinized rats. Immunoglobulin isotypes and subclasses (IgM, IgG1, IgG2 alpha, IgG2b) of total circulating Ab were measured pre-PE and up to 21 days post-PE, using ELISA (enzyme-linked immunosorbent assay) and specific mouse antirat monoclonal Ab. Antiguinea-pig (GP) XG Ab (IgM, IgG2a) serum levels were measured using cellular ELISA with cultured GP endothelial cells as targets. Sx alone significantly reduced XG IgM serum levels (p < 0.0001). Maximal rebound of total and XG IgM was observed on day 3 post-PE, reaching 674% and 187% of the pre-PE levels, respectively; these overshoots were entirely suppressed by Sx (p < 0.005 for total IgM; p < 0.0001 for XG IgM). Total IgG2a, IgG2b and IgG1 as well as XG IgG2a serum levels did not show significant overshoot post-PE. The activity of the complement classical pathway (mean +/- SD), assessed by CH50, was decreased at 51 +/- 19% of basal value 15 minutes after PE, and had returned to baseline level by day 2 post-PE with or without Sx. IN CONCLUSION (1) Six alone significantly reduced XG IgM serum levels; (2) early post-PE Ab rebound was mainly observed for IgM; (3) both total and XG IgM rebound was inhibited by Sx. This suggests that Sx probably removes a significant proportion of IgM producing cells undergoing post-PE stimulation. These data provide a rationale for combining PE with Sx in ABO-incompatible and discordant XG transplantation.
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Affiliation(s)
- R Reding
- Laboratory of Experimental Surgery, University of Louvain Medical School, Brussels, Belgium
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Vanhove B, Martin R, Lipp J, Bach FH. Human xenoreactive natural antibodies of the IgM isotype activate pig endothelial cells. Xenotransplantation 1994. [DOI: 10.1111/j.1399-3089.1994.tb00046.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Affiliation(s)
- J F Markmann
- Department of Surgery, Hospital of the University of Pennsylvania
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Allaire E, Guettier C, Bruneval P, Plissonnier D, Michel JB. Cell-free arterial grafts: morphologic characteristics of aortic isografts, allografts, and xenografts in rats. J Vasc Surg 1994; 19:446-56. [PMID: 8126857 DOI: 10.1016/s0741-5214(94)70071-0] [Citation(s) in RCA: 144] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE Chronic rejection of arterial allografts and xenografts results in arterial wall dilation and rupture, making them unsuitable for long-term arterial replacement in vascular surgery. In the arterial wall, as in other organs, the cells probably carry major antigenic determinants. Arterial wall cellular components can be removed by detergent treatment to produce a graftable matrix tube. METHODS We compared the patency and macroscopic and microscopic morphologic changes that occurred in sodium dodecyl sulfate (SDS)-treated and untreated arterial isografts, allografts, and xenografts 2 months after implantation in rats. We quantified elastin, collagen, and nuclear density in the three layers of the graft wall (intima, media, and adventitia) by morphometric methods. The SDS treatment removed endothelial and smooth muscle cells and cells in the adventitia but preserved elastin and collagen extracellular matrix. RESULTS All arterial xenografts, whether SDS treated or untreated, were aneurysmal 2 months after grafting, with loss of the medial cellular and extracellular components. In allografts, SDS treatment prevented dilation, reduced adventitial inflammatory infiltration, and preserved medial elastin. The SDS-treated allografts had an evenly distributed, noninflammatory intimal thickening that was richer in elastin fibers than that in untreated allografts. CONCLUSIONS These results suggest an interspecies, but not an intraspecies, graft antigenicity of arterial extracellular matrix. The SDS treatment prevented chronic rejection of the arterial allograft and led to the proliferation of an elastin-rich and adapted intima.
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Affiliation(s)
- E Allaire
- Unit 367 INSERM, Hôpital Broussais, Paris, France
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