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Singh AK, Chan JL, DiChiacchio L, Hardy NL, Corcoran PC, Lewis BGT, Thomas ML, Burke AP, Ayares D, Horvath KA, Mohiuddin MM. Cardiac xenografts show reduced survival in the absence of transgenic human thrombomodulin expression in donor pigs. Xenotransplantation 2018; 26:e12465. [PMID: 30290025 DOI: 10.1111/xen.12465] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 07/20/2018] [Accepted: 09/10/2018] [Indexed: 12/13/2022]
Abstract
A combination of genetic manipulations of donor organs and target-specific immunosuppression is instrumental in achieving long-term cardiac xenograft survival. Recently, results from our preclinical pig-to-baboon heterotopic cardiac xenotransplantation model suggest that a three-pronged approach is successful in extending xenograft survival: (a) α-1,3-galactosyl transferase (Gal) gene knockout in donor pigs (GTKO) to prevent Gal-specific antibody-mediated rejection; (b) transgenic expression of human complement regulatory proteins (hCRP; hCD46) and human thromboregulatory protein thrombomodulin (hTBM) to avoid complement activation and coagulation dysregulation; and (c) effective induction and maintenance of immunomodulation, particularly through co-stimulation blockade of CD40-CD40L pathways with anti-CD40 (2C10R4) monoclonal antibody (mAb). Using this combination of manipulations, we reported significant improvement in cardiac xenograft survival. In this study, we are reporting the survival of cardiac xenotransplantation recipients (n = 3) receiving xenografts from pigs without the expression of hTBM (GTKO.CD46). We observed that all grafts underwent rejection at an early time point (median 70 days) despite utilization of our previously reported successful immunosuppression regimen and effective control of non-Gal antibody response. These results support our hypothesis that transgenic expression of human thrombomodulin in donor pigs confers an independent protective effect for xenograft survival in the setting of a co-stimulation blockade-based immunomodulatory regimen.
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Affiliation(s)
- Avneesh K Singh
- Cardiothoracic Surgery Research Program/National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland.,Department of Surgery, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Joshua L Chan
- Cardiothoracic Surgery Research Program/National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Laura DiChiacchio
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Naomi L Hardy
- Department of Pathology at the University of Maryland Medical Center, University of Maryland, Baltimore, Maryland
| | - Philip C Corcoran
- Cardiothoracic Surgery Research Program/National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Billeta G T Lewis
- Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, Maryland
| | - Marvin L Thomas
- Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, Maryland
| | - Allen P Burke
- Department of Pathology at the University of Maryland Medical Center, University of Maryland, Baltimore, Maryland
| | | | - Keith A Horvath
- Cardiothoracic Surgery Research Program/National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Muhammad M Mohiuddin
- Cardiothoracic Surgery Research Program/National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland.,Department of Surgery, School of Medicine, University of Maryland, Baltimore, Maryland
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2
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Iwase H, Kobayashi T. Current status of pig kidney xenotransplantation. Int J Surg 2015; 23:229-233. [PMID: 26305729 PMCID: PMC4684762 DOI: 10.1016/j.ijsu.2015.07.721] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 07/21/2015] [Accepted: 07/26/2015] [Indexed: 12/27/2022]
Abstract
Significant progress in life-supporting kidney xenograft survival in nonhuman primates (NHPs) has been associated largely with the increasing availability of pigs with genetic modifications that protect the pig tissues from the primate immune response and/or correct molecular incompatibilities between pig and primate. Blockade of the CD40/CD154 costimulation pathway with anti-CD154 mAb therapy has contributed to prolongation of kidney xenograft survival, although this agent may not be clinically available. An anti-CD40 mAb-based regimen is proving equally successful, but blockade of the CD28/B7 pathway is inadequate. Severe proteinuria were uniformly documented in the early studies of pig kidney xenotransplantation, but whether this resulted from immune injury or from physiological incompatibilities between the species, or both, remained uncertain. Recent experiments suggest it was related to a continuing immune response. Before 2014, the longest survival of a pig kidney graft in a NHP was 90 days, though graft survival >30 days was unusual. Recently this has been extended to >125 days, without features of a consumptive coagulopathy or a protein-losing nephropathy. In conclusion, overcoming the immune, coagulation, and inflammatory responses by the development of precise genetic modifications in donor pigs, along with effective immunosuppressive and anticoagulant/anti-inflammatory therapy is advancing the field towards clinical trials.
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Affiliation(s)
- Hayato Iwase
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA.
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Mohiuddin MM, Reichart B, Byrne GW, McGregor CGA. Current status of pig heart xenotransplantation. Int J Surg 2015; 23:234-239. [PMID: 26318967 PMCID: PMC4684783 DOI: 10.1016/j.ijsu.2015.08.038] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/06/2015] [Accepted: 08/12/2015] [Indexed: 02/03/2023]
Abstract
Significant progress in understanding and overcoming cardiac xenograft rejection using a clinically relevant large animal pig-to-baboon model has accelerated in recent years. This advancement is based on improved immune suppression, which attained more effective regulation of B lymphocytes and possibly newer donor genetics. These improvements have enhanced heterotopic cardiac xenograft survival from a few weeks to over 2 years, achieved intrathoracic heterotopic cardiac xenograft survival of 50 days and orthotopic survival of 57 days. This encouraging progress has rekindled interest in xenotransplantation research and refocused efforts on preclinical orthotopic cardiac xenotransplantation.
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Affiliation(s)
| | - Bruno Reichart
- Walter-Brendel-Centre for Experimental Medicine, Ludwig-Maximilians-University, Munich, Germany
| | - Guerard W Byrne
- Institute of Cardiovascular Science, University College London, London, UK; Department of Surgery, Mayo Clinic Rochester, MN, USA
| | - Christopher G A McGregor
- Institute of Cardiovascular Science, University College London, London, UK; Department of Surgery, Mayo Clinic Rochester, MN, USA
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4
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Ezzelarab MB, Cooper DKC. Systemic inflammation in xenograft recipients (SIXR): A new paradigm in pig-to-primate xenotransplantation? Int J Surg 2015. [PMID: 26209584 DOI: 10.1016/j.ijsu.2015.07.643] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Inflammation is a complex response that involves interactions between multiple proteins in the human body. The interaction between inflammation and coagulation is well-recognized, but its role in the dysregulation of coagulation in xenograft recipients is not well-understood. Additionally, inflammation is known to prevent the development of T cell tolerance after transplantation. Recent evidence indicates that systemic inflammation precedes and may be promoting activation of coagulation after pig-to-primate xenotransplantation. Activated recipient innate immune cells expressing tissue factor are increased after xenotransplantation, irrespective of immunosuppressive therapy. With immunosuppression, C-reactive protein (C-RP), fibrinogen, and interleukin-6 levels are significantly increased in pig artery patch recipients. In pig organ recipients, increased C-RP levels are observed prior to the development of features of consumptive coagulopathy. Systemic inflammation in xenograft recipients (Sixr) may be a key factor in the development of dysregulation of coagulation, as well as in resistance to immunosuppressive therapy. While genetic modification of the donor pigs provides protection against humoral responses and the development of thrombotic microangiopathy, therapeutic prevention of Sixr may be essential in order to prevent systemic dysregulation of coagulation in xenograft recipients without the use of intensive immunosuppression.
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Affiliation(s)
- Mohamed B Ezzelarab
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
| | - David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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5
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Ramackers W, Friedrich L, Klose J, Vondran F, Bergmann S, Schüttler W, Johanning K, Werwitzke S, Trummer A, Bröcker V, Klempnauer J, Winkler M, Tiede A. Recombinant human antithrombin prevents xenogenic activation of hemostasis in a model of pig-to-human kidney transplantation. Xenotransplantation 2014; 21:367-75. [DOI: 10.1111/xen.12104] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 03/14/2014] [Indexed: 12/17/2022]
Affiliation(s)
- Wolf Ramackers
- Department of General, Visceral and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Lars Friedrich
- Department of Anesthesiology and Intensive Care; Hannover Medical School; Hannover Germany
| | - Johannes Klose
- Department of General, Visceral and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Florian Vondran
- Department of General, Visceral and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Sabine Bergmann
- Department of General, Visceral and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Wolfgang Schüttler
- Department of General, Visceral and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Kai Johanning
- Department of Anesthesiology and Intensive Care; Hannover Medical School; Hannover Germany
| | - Sonja Werwitzke
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School; Hannover Germany
| | - Arne Trummer
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School; Hannover Germany
| | - Verena Bröcker
- Department of Pathology; Hannover Medical School; Hannover Germany
| | - Jürgen Klempnauer
- Department of General, Visceral and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Michael Winkler
- Department of General, Visceral and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Andreas Tiede
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School; Hannover Germany
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Iwase H, Ezzelarab MB, Ekser B, Cooper DKC. The role of platelets in coagulation dysfunction in xenotransplantation, and therapeutic options. Xenotransplantation 2014; 21:201-20. [PMID: 24571124 DOI: 10.1111/xen.12085] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 01/08/2014] [Indexed: 12/11/2022]
Abstract
Xenotransplantation could resolve the increasing discrepancy between the availability of deceased human donor organs and the demand for transplantation. Most advances in this field have resulted from the introduction of genetically engineered pigs, e.g., α1,3-galactosyltransferase gene-knockout (GTKO) pigs transgenic for one or more human complement-regulatory proteins (e.g., CD55, CD46, CD59). Failure of these grafts has not been associated with the classical features of acute humoral xenograft rejection, but with the development of thrombotic microangiopathy in the graft and/or consumptive coagulopathy in the recipient. Although the precise mechanisms of coagulation dysregulation remain unclear, molecular incompatibilities between primate coagulation factors and pig natural anticoagulants exacerbate the thrombotic state within the xenograft vasculature. Platelets play a crucial role in thrombosis and contribute to the coagulation disorder in xenotransplantation. They are therefore important targets if this barrier is to be overcome. Further genetic manipulation of the organ-source pigs, such as pigs that express one or more coagulation-regulatory genes (e.g., thrombomodulin, endothelial protein C receptor, tissue factor pathway inhibitor, CD39), is anticipated to inhibit platelet activation and the generation of thrombus. In addition, adjunctive pharmacologic anti-platelet therapy may be required. The genetic manipulations that are currently being tested are reviewed, as are the potential pharmacologic agents that may prove beneficial.
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Affiliation(s)
- Hayato Iwase
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
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7
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Cowan PJ, Cooper DKC, d'Apice AJF. Kidney xenotransplantation. Kidney Int 2014; 85:265-75. [PMID: 24088952 PMCID: PMC3946635 DOI: 10.1038/ki.2013.381] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 07/12/2013] [Accepted: 07/17/2013] [Indexed: 12/14/2022]
Abstract
Xenotransplantation using pigs as donors offers the possibility of eliminating the chronic shortage of donor kidneys, but there are several obstacles to be overcome before this goal can be achieved. Preclinical studies have shown that, while porcine renal xenografts are broadly compatible physiologically, they provoke a complex rejection process involving preformed and elicited antibodies, heightened innate immune cell reactivity, dysregulated coagulation, and a strong T cell-mediated adaptive response. Furthermore, the susceptibility of the xenograft to proinflammatory and procoagulant stimuli is probably increased by cross-species molecular defects in regulatory pathways. To balance these disadvantages, xenotransplantation has at its disposal a unique tool to address particular rejection mechanisms and incompatibilities: genetic modification of the donor. This review focuses on the pathophysiology of porcine renal xenograft rejection, and on the significant genetic, pharmacological, and technical progress that has been made to prolong xenograft survival.
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Affiliation(s)
- Peter J Cowan
- 1] Immunology Research Centre, St Vincent's Hospital, Melbourne, Victoria, Australia [2] Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Anthony J F d'Apice
- 1] Immunology Research Centre, St Vincent's Hospital, Melbourne, Victoria, Australia [2] Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
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Byrne GW, Azimzadeh AM, Ezzelarab M, Tazelaar HD, Ekser B, Pierson RN, Robson SC, Cooper DKC, McGregor CGA. Histopathologic insights into the mechanism of anti-non-Gal antibody-mediated pig cardiac xenograft rejection. Xenotransplantation 2013; 20:292-307. [PMID: 25098626 PMCID: PMC4126170 DOI: 10.1111/xen.12050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/31/2013] [Indexed: 01/13/2023]
Abstract
The histopathology of cardiac xenograft rejection has evolved over the last 20 yr with the development of new modalities for limiting antibody-mediated injury, advancing regimens for immune suppression, and an ever-widening variety of new donor genetics. These new technologies have helped us progress from what was once an overwhelming anti-Gal-mediated hyperacute rejection to a more protracted anti-Gal-mediated vascular rejection to what is now a more complex manifestation of non-Gal humoral rejection and coagulation dysregulation. This review summarizes the changing histopathology of Gal- and non-Gal-mediated cardiac xenograft rejection and discusses the contributions of immune-mediated injury, species-specific immune-independent factors, transplant and therapeutic procedures, and donor genetics to the overall mechanism(s) of cardiac xenograft rejection.
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Affiliation(s)
- Guerard W Byrne
- Institute of Cardiovascular Science, University College London, London, UK; Department of Surgery, Mayo Clinic, Rochester, MN, USA
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9
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Asmal M, Whitney JB, Luedemann C, Carville A, Steen R, Letvin NL, Geiben-Lynn R. In vivo anti-HIV activity of the heparin-activated serine protease inhibitor antithrombin III encapsulated in lymph-targeting immunoliposomes. PLoS One 2012; 7:e48234. [PMID: 23133620 PMCID: PMC3487854 DOI: 10.1371/journal.pone.0048234] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 09/28/2012] [Indexed: 11/23/2022] Open
Abstract
Endogenous serine protease inhibitors (serpins) are anti-inflammatory mediators with multiple biologic functions. Several serpins have been reported to modulate HIV pathogenesis, or exhibit potent anti-HIV activity in vitro, but the efficacy of serpins as therapeutic agents for HIV in vivo has not yet been demonstrated. In the present study, we show that heparin-activated antithrombin III (hep-ATIII), a member of the serpin family, significantly inhibits lentiviral replication in a non-human primate model. We further demonstrate greater than one log(10) reduction in plasma viremia in the nonhuman primate system by loading of hep-ATIII into anti-HLA-DR immunoliposomes, which target tissue reservoirs of viral replication. We also demonstrate the utility of hep-ATIIII as a potential salvage agent for HIV strains resistant to standard anti-retroviral treatment. Finally, we applied gene-expression arrays to analyze hep-ATIII-induced host cell interactomes and found that downstream of hep-ATIII, two independent gene networks were modulated by host factors prostaglandin synthetase-2, ERK1/2 and NFκB. Ultimately, understanding how serpins, such as hep-ATIII, regulate host responses during HIV infection may reveal new avenues for therapeutic intervention.
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Affiliation(s)
- Mohammed Asmal
- Division of Viral Pathogenesis, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America.
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10
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Abstract
PURPOSE OF REVIEW Cardiac xenotransplantation (CXTx) remains a promising approach to alleviate the chronic shortage of donor hearts. This review summarizes recent results of heterotopic and orthotopic CXTx, highlights the role of non-Gal antibody in xenograft rejection, and discusses challenges to clinical orthotopic CXTx. RECENT FINDINGS Pigs mutated in the α 1,3 galactosyltransferase gene (GTKO pigs) are devoid of the galactose α1,3 galactose (αGal) carbohydrate antigen. This situation effectively eliminates any role for anti-Gal antibody in GTKO cardiac xenograft rejection. Survival of heterotopic GTKO cardiac xenografts in nonhuman primates continues to increase. GTKO graft rejection commonly involves vascular antibody deposition and variable complement deposition. Non-Gal antibody responses to porcine antigens associated with inflammation, complement, and hemostatic regulation and to new carbohydrate antigens have been identified. Their contribution to rejection remains under investigation. Orthotopic CXTx is limited by early perioperative cardiac xenograft dysfunction (PCXD). However, hearts affected by PCXD recover full cardiac function and orthotopic survival up to 2 months without rejection has been reported. SUMMARY CXTx remains a promising technology for treating end-stage cardiac failure. Genetic modification of the donor and refinement of immunosuppressive regimens have extended heterotopic cardiac xenograft survival from minutes to in excess of 8 months.
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Affiliation(s)
- Guerard W Byrne
- University College London, Institute for Cardiovascular Sciences, London, UK.
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11
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Abstract
Microvascular thrombosis, following the activation of clotting cascade, is a hallmark of porcine solid organ xenograft rejection. The analysis of differences between human, monkey, and pig coagulation systems is crucial when monkey is used as animal model and pig as organ donor in xenotransplantation. Thrombosis, according to many authors, may be due to the molecular incompatibilities between natural anticoagulants present on pig endothelium and primate activated coagulation factors. The generation of activated protein C (PC) is critical for the physiological anticoagulation. One of the major incompatibilities may be related to the inability of pig thrombomodulin (TM) and endothelial protein C receptor to activate the recipient (primate) circulating PC in the presence of thrombin. Tissue factor pathway inhibitor (TFPI), is the primary inhibitor of tissue factor (TF)-induced coagulation. TFPI directly inhibits the activated factor X (FXa) and blocks the procoagulant activity of the TF/factor VIIa (FVIIa) complex by forming a quaternary TF/FVIIa/FXa/TFPI complex. Microvascular thrombosis, observed in the organ transplant, may also be due to the failure of pig TFPI to bind human FXa efficiently and inhibit human FVIIa/TF activity. The methods described in this chapter can be useful for the identification and characterization of primate and pig coagulation factors (isolated from a small volume of blood) by using SDS-PAGE and immunoblotting. Differences in molecular weight can help in the identification of the origin (pig or primate) of coagulation proteins in plasma from the recipient of xenografts. On the other hand, in vitro models of PC pathway and TFPI on human umbilical vein endothelial cells (HUVEC) and porcine aortic endothelial cells (PAEC) are described which can be used for studying incompatibilities between primate and pig.
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Schmelzle M, Cowan PJ, Robson SC. Which anti-platelet therapies might be beneficial in xenotransplantation? Xenotransplantation 2011; 18:79-87. [PMID: 21496115 DOI: 10.1111/j.1399-3089.2011.00628.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Xenotransplantation could provide an unlimited and elective supply of grafts, once mechanisms of graft loss and vascular injury are better understood. The development of α-1,3-galactosyltransferase gene-knockout (GalT-KO) swine with the removal of a dominant xeno-antigen has been an important advance; however, delayed xenograft and acute vascular reaction in GalT-KO animals persist. These occur, at least in part, because of humoral reactions that result in vascular injury. Intrinsic molecular incompatibilities in the regulation of blood clotting and extracellular nucleotide homeostasis between discordant species may also predispose to thrombophilia within the vasculature of xenografts. Although limited benefits have been achieved with currently available pharmacological anti-thrombotics and anti-coagulants, the highly complex mechanisms of platelet activation and thrombosis in xenograft rejection also require potent immunosuppressive interventions. We will focus on recent thromboregulatory approaches while elucidating appropriate anti-platelet mechanisms. We will discuss potential benefits of additional anti-thrombotic interventions that are possible in transgenic swine and review recent developments in pharmacological anti-platelet therapy.
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Affiliation(s)
- Moritz Schmelzle
- Liver Center and Transplantation Institute, Department of Medicine and Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
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13
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Effects of long-term administration of recombinant human protein C in xenografted primates. Transplantation 2011; 91:161-8. [PMID: 21088649 DOI: 10.1097/tp.0b013e318200ba0e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The role potential of recombinant human activated protein C (rhaPC), a recently developed molecule with anticoagulant and antiinflammatory properties, in prolonging survival in immunosuppressed primate recipients of porcine renal xenografts has been evaluated. METHODS rhaPC was administered daily for 5 days (24 μg/kg/hr; group A; n = 3) or throughout the postoperative period (8-24 μg/kg/hr; group B; n = 2; or 24-48 μg/kg/hr; group C; n = 4). Animals in group D (n = 2) received rhaPC daily (24 μg/kg/hr) combined with recombinant human antithrombin (84 U/kg every 8 hr). Two animals served as control (group E). RESULTS The results indicate that rhaPC is protective against fibrin deposition early after transplantation but does not prevent fibrin deposition and the occurrence of acute humoral xenograft rejection (AHXR) later on. Animals in the study survived between 8 and 55 days. At the dose used, rhaPC is able to prevent fibrin deposition in the graft in the first 2 weeks after xenotransplantation, except when it is administered in conjunction with antithrombin. However, rhaPC did not prevent the eventual occurrence of AHXR in primate recipients of porcine xenografts. CONCLUSIONS In this pig to primate model, rhaPC confers a short advantage in the prevention of early perioperative xenograft damage but does not represent an effective strategy for preventing AHXR.
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Miwa Y, Yamamoto K, Onishi A, Iwamoto M, Yazaki S, Haneda M, Iwasaki K, Liu D, Ogawa H, Nagasaka T, Uchida K, Nakao A, Kadomatsu K, Kobayashi T. Potential value of human thrombomodulin and DAF expression for coagulation control in pig-to-human xenotransplantation. Xenotransplantation 2010; 17:26-37. [PMID: 20149186 DOI: 10.1111/j.1399-3089.2009.00555.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Problems of coagulation disorder remain to be resolved in pig-to-primate xenotransplantation. Molecular incompatibilities in the coagulation systems between pigs and humans, such as the thrombomodulin (TM)-protein C system or direct prothrombinase activity, have been suggested as possible causes. Coagulation and complement activation are closely related to each other. The purpose of this study was to elucidate the protective effects on the coagulation system of the expression of human TM and decay accelerating factor (hDAF) (for inhibition of complement activation) in pig endothelial cells. METHODS Human aortic endothelial cells (HAEC), porcine aortic endothelial cells (PAEC), hDAF-expressing PAEC (hDAF-PAEC), hDAF/Endo-beta-galactosidase C-expressing PAEC (hDAF/EndoGalC-PAEC), hTM-expressing PAEC (hTM-PAEC), hDAF/hTM expressing-PAEC (hDAF/hTM-PAEC), and hDAF/EndoGalC/hTM-expressing PAEC (hDAF/EndoGalC/hTM-PAEC) were used in this study. Coagulation activity was examined by clotting, activated protein C (APC), and thrombin generation assay. RESULTS A large difference was observed in clotting time of human plasma when exposed to PAEC (170 s) and HAEC (1020 s). hTM expression on PAEC was proven to produce a comparable level of APC to that produced by HAEC, which prolonged the clotting time, though not to the level of HAEC. Pretreatment with human sera considerably shortened the clotting time in PAEC (80 s). hDAF-PAEC significantly inhibited such a shortening of clotting time by reductions in tissue factor expression and thrombin generation. Thrombin generation through direct prothrombinase activity, which was detected only in PAEC, could be suppressed by hTM expression. Suppression of antibody binding and complement activation improved clotting time not in PAEC, but in PAEC expressing hTM. CONCLUSIONS In addition to effective suppression of antibody-induced complement activation, hTM expression in PAEC may be essential for regulating procoagulant activity in xenotransplantation.
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Affiliation(s)
- Yuko Miwa
- Department of Applied Immunology, Nagoya University School of Medicine, Nagoya, Japan
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Crikis S, Zhang XM, Dezfouli S, Dwyer KM, Murray-Segal LM, Salvaris E, Selan C, Robson SC, Nandurkar HH, Cowan PJ, d’Apice AJF. Anti-inflammatory and anticoagulant effects of transgenic expression of human thrombomodulin in mice. Am J Transplant 2010; 10:242-50. [PMID: 20055798 PMCID: PMC5472991 DOI: 10.1111/j.1600-6143.2009.02939.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Thrombomodulin (TBM) is an important vascular anticoagulant that has species specific effects. When expressed as a transgene in pigs, human (h)TBM might abrogate thrombotic manifestations of acute vascular rejection (AVR) that occur when GalT-KO and/or complement regulator transgenic pig organs are transplanted to primates. hTBM transgenic mice were generated and characterized to determine whether this approach might show benefit without the development of deleterious hemorrhagic phenotypes. hTBM mice are viable and are not subject to spontaneous hemorrhage, although they have a prolonged bleeding time. They are resistant to intravenous collagen-induced pulmonary thromboembolism, stasis-induced venous thrombosis and pulmonary embolism. Cardiac grafts from hTBM mice to rats treated with cyclosporine in a model of AVR have prolonged survival compared to controls. hTBM reduced the inflammatory reaction in the vein wall in the stasis-induced thrombosis and mouse-to-rat xenograft models and reduced HMGB1 levels in LPS-treated mice. These results indicate that transgenic expression of hTBM has anticoagulant and antiinflammatory effects that are graft-protective in murine models.
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Affiliation(s)
- S. Crikis
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia,Department of Medicine, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia
| | - X. M. Zhang
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia
| | - S. Dezfouli
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia
| | - K. M. Dwyer
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia,Department of Medicine, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia
| | - L. M. Murray-Segal
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia
| | - E. Salvaris
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia
| | - C. Selan
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia
| | - S. C. Robson
- Liver Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - H. H. Nandurkar
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia,Department of Medicine, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia
| | - P. J. Cowan
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia,Department of Medicine, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia
| | - A. J. F. d’Apice
- Immunology Research Centre, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia,Department of Medicine, The University of Melbourne, St. Vincent’s Hospital, Fitzroy, Vic. 3065, Australia,Corresponding author: Professor Anthony J. F. d’Apice,
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Kim MK, Oh JY, Ko JH, Lee HJ, Jung JH, Wee WR, Lee JH, Park CG, Kim SJ, Ahn C, Kim SJ, Hwang SY. DNA microarray-based gene expression profiling in porcine keratocytes and corneal endothelial cells and comparative analysis associated with xeno-related rejection. J Korean Med Sci 2009; 24:189-96. [PMID: 19399257 PMCID: PMC2672115 DOI: 10.3346/jkms.2009.24.2.189] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Accepted: 06/24/2008] [Indexed: 11/20/2022] Open
Abstract
Porcine to rat corneal xenotransplantation resulted in severe inflammation and rejection of the corneal stroma, whereas an allograft showed mainly endothelial cell-associated rejection. We, therefore, investigated and compared the gene expression between porcine keratocytes and corneal endothelial cells. RNA was isolated from primary cultured porcine or human keratocytes and porcine corneal endothelial cells. Gene expression was comparatively analyzed after normalization with microarray method using Platinum pig 13 K oligo chip (GenoCheck Co., Ltd., Ansan, Korea). Real-time polymerase chain reaction (PCR) was performed for C1R, CCL2, CXCL6, and HLA-A in porcine keratocytes and corneal endothelial cells. As a result, upregulated expression more than 2 folds was observed in 1,162 genes of porcine keratocytes versus porcine endothelial cells. Among the immune-regulatory genes, SEMA3C, CCL2, CXCL6, F3, HLA-A, CD97, IFI30, C1R, and G1P3 were highly expressed in porcine keratocytes, compared to porcine corneal endothelial cells or human keratocytes. When measured by real-time PCR, the expression of C1R, CCL2, and HLA-A was higher in porcine keratocytes compared to that in porcine corneal endothelial cells. In conclusion, the increased expression of C1R, CCL2, and HLA-A genes in porcine keratocytes might be responsible for the stromal rejection observed in a porcine to rat corneal xenotransplantation.
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Affiliation(s)
- Mee Kum Kim
- Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
- Xenotransplantation Research Center and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Joo Youn Oh
- Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
- Xenotransplantation Research Center and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Jung Hwa Ko
- Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
- Xenotransplantation Research Center and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Hyun Ju Lee
- Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
- Xenotransplantation Research Center and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Jin Ho Jung
- Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
| | - Won Ryang Wee
- Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
- Xenotransplantation Research Center and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Jin Hak Lee
- Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
| | - Chung-Gyu Park
- Xenotransplantation Research Center and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Korea
| | - Sang Joon Kim
- Xenotransplantation Research Center and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
- Department of Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Curie Ahn
- Xenotransplantation Research Center and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Seung-Jun Kim
- Division of Molecular and Life Science, Hanyang University, Seoul, Korea
- GenoCheck Co. Ltd., Ansan, Korea
| | - Seung Yong Hwang
- Division of Molecular and Life Science, Hanyang University, Seoul, Korea
- GenoCheck Co. Ltd., Ansan, Korea
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Cowan PJ, d'Apice AJF. Complement activation and coagulation in xenotransplantation. Immunol Cell Biol 2009; 87:203-8. [DOI: 10.1038/icb.2008.107] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Peter J Cowan
- Immunology Research Centre, St Vincent's Hospital Melbourne Melbourne Victoria Australia
- Department of Medicine, University of Melbourne Melbourne Victoria Australia
| | - Anthony JF d'Apice
- Immunology Research Centre, St Vincent's Hospital Melbourne Melbourne Victoria Australia
- Department of Medicine, University of Melbourne Melbourne Victoria Australia
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Byrne GW, Stalboerger PG, Davila E, Heppelmann CJ, Gazi MH, McGregor HCJ, LaBreche PT, Davies WR, Rao VP, Oi K, Tazelaar HD, Logan JS, McGregor CGA. Proteomic identification of non-Gal antibody targets after pig-to-primate cardiac xenotransplantation. Xenotransplantation 2009; 15:268-76. [PMID: 18957049 DOI: 10.1111/j.1399-3089.2008.00480.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Experience with non-antigenic galactose alpha1,3 galactose (alphaGal) polymers and development of alphaGal deficient pigs has reduced or eliminated the significance of this antigen in xenograft rejection. Despite these advances, delayed xenograft rejection (DXR) continues to occur most likely due to antibody responses to non-Gal endothelial cell (EC) antigens. METHODS To gauge the diversity of the non-Gal antibody response we used antibody derived from CD46 transgenic heterotopic cardiac xenografts performed without T-cell immunosuppression, Group A (n = 4) and Gal knockout (GT-KO) heart transplants under tacrolimus and sirolimus immunosuppression, Group B (n = 8). Non-Gal antibody was measured by flow cytometry and by western blots using GT-KO EC membrane antigens. A nanoLC/MS/MS analysis of proteins recovered from 2D gels was used to identify target antigens. RESULTS Group A recipients exhibited a mixed cellular and humoral rejection. Group B recipients mainly exhibited classical DXR. Western blot analysis showed a non-Gal antibody response induced by GT+ and GT-KO hearts to an overlapping set of pig aortic EC membrane antigens. Proteomic analysis identified 14 potential target antigens but failed to define several immunodominant targets. CONCLUSIONS These experiments indicate that the non-Gal antibody response is directed to a number of stress response and inflammation related pig EC antigens and a few undefined targets. Further analysis of these antibody specificities using alternative methods is required to more fully define the repertoire of non-Gal antibody responses.
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Affiliation(s)
- Guerard W Byrne
- Department of Surgery, Mayo Clinic, Rochester, MN 55905, USA.
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The coagulation barrier in xenotransplantation: incompatibilities and strategies to overcome them. Curr Opin Organ Transplant 2008; 13:178-83. [PMID: 18685300 DOI: 10.1097/mot.0b013e3282f63c74] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Dysregulated coagulation is now recognized as a major contributor to graft loss in xenotransplantation. This review summarizes recent data on putative mechanisms of pathogenic coagulation in xenotransplantation and discusses progress on strategies to overcome them. RECENT FINDINGS Evidence continues to grow that the primary cause of failure of pig cardiac and renal xenografts is probably antibody-mediated injury to the endothelium, leading to development of microvascular thrombosis. Several factors that may exacerbate the problem will remain, even in the absence of a humoral response. These include molecular incompatibilities that affect the control of coagulation - in particular the failure of pig thrombomodulin to activate the primate protein C pathway - and platelet reactivity. Expression of anticoagulant and antiplatelet molecules within the graft is a potential solution that has been successfully tested in rodent models and will soon be applied to the pig-to-primate model. This strategy, in parallel with physical methods such as encasing islets in a protective layer, also holds promise for reducing the thrombogenicity of pig islet xenografts. SUMMARY Thrombosis is a barrier to long-term survival and function of porcine xenografts, which may eventually be overcome by various combinations of genetic and physical manipulation.
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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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Yang YG, Sykes M. Xenotransplantation: current status and a perspective on the future. Nat Rev Immunol 2007; 7:519-31. [PMID: 17571072 DOI: 10.1038/nri2099] [Citation(s) in RCA: 231] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Xenotransplantation using pigs as the transplant source has the potential to resolve the severe shortage of human organ donors. Although the development of relatively non-toxic immunosuppressive or tolerance-inducing regimens will be required to justify clinical trials using pig organs, recent advances in our understanding of the biology of xenograft rejection and zoonotic infections, and the generation of alpha1,3-galactosyltransferase-deficient pigs have moved this approach closer to clinical application. This Review highlights the major obstacles impeding the translation of xenotransplantation into clinical therapies and the potential solutions, providing a perspective on the future of clinical xenotransplantation.
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Affiliation(s)
- Yong-Guang Yang
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02129, USA
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Byrne GW, Davies WR, Oi K, Rao VP, Teotia SS, Ricci D, Tazelaar HD, Walker RC, Logan JS, McGregor CGA. Increased immunosuppression, not anticoagulation, extends cardiac xenograft survival. Transplantation 2007; 82:1787-91. [PMID: 17198277 DOI: 10.1097/01.tp.0000251387.40499.0f] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Cardiac xenograft function is lost due to delayed xenograft rejection (DXR) characterized by microvascular thrombosis and myocardial necrosis. The cause of DXR is unknown but may result from thrombosis induced by antibody-mediated activation of endothelial cells and/or by incompatibilities in thromboregulatory interactions. METHODS To examine these issues, a series (Groups 1-6) of previous transgenic CD46 pig-to-baboon heterotopic cardiac transplants were reanalyzed for baseline immunosuppressive levels, graft survival and infectious complications with and without systemic anticoagulation. Groups 1-4 received low dose tacrolimus and sirolimus maintenance therapy, with splenectomy, anti-CD20 and daily alpha-Gal polymer. Group 1 recipients received no anticoagulation. Groups 2-4 were anticoagulated with aspirin and Plavix, Lovenox, or Coumadin, respectively. Group 5 was treated with Lovenox and high dose tacrolimus and sirolimus maintenance therapy. Group 6 recipients received no postoperative anticoagulation but the same immunosuppression as group 5. RESULTS Median survival (15-22 days) within groups 1-4 was not significantly different. At rejection all tissues exhibited microvascular thrombosis, coagulative necrosis and similar levels of platelet and fibrin deposition. Groups 5 and 6 median survival (76 days) was significantly increased compared to groups 1-4. There was no significant difference in median survival between Lovenox treated recipients (68 days) and anticoagulant free recipients (96 days). Rejected tissues showed vascular antibody deposition, microvascular thrombosis, and myocyte necrosis. CONCLUSION Significant prolongation in xenograft survival is achieved by improved immunosuppression. These results suggest that ongoing immune responses remain the major stimulus for DXR.
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Affiliation(s)
- Guerard W Byrne
- William J. von Liebig Transplant Center, Mayo Clinic-Rochester, Rochester, MN 55905, USA.
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Abstract
Acute humoral rejection remains the major barrier to long-term pig-to-primate xenograft survival, and microvascular thrombosis is a critical element of the rejection process. It appears that persistent endothelial cell activation and injury, by even low levels of anti-graft antibodies, eventually overwhelm the cellular anticoagulant defences and promote the development of thrombotic microangiopathy. Porcine endothelium may be particularly vulnerable because of cross-species molecular incompatibilities affecting the function of thrombomodulin and possibly TFPI. Recent data from small animal models suggest that transgenic overexpression of anti-thrombotic molecules on xenograft endothelium is capable of inhibiting intravascular thrombosis and preventing acute humoral rejection. In conjunction with existing genetic modifications (e.g. Gal KO, hDAF), this is a promising strategy to move xenotransplantation to the clinic.
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Affiliation(s)
- Peter J Cowan
- Immunology Research Centre, St Vincent's Health, Department of Medicine, University of Melbourne, Melbourne, Vic., Australia.
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