1
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Galili U. Anti-Non-Gal Antibodies Against Porcine Protein Antigens as Barrier to Long-Term Grafting of Xenografts in Humans. Xenotransplantation 2024; 31:e12875. [PMID: 38990768 DOI: 10.1111/xen.12875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/22/2024] [Accepted: 06/14/2024] [Indexed: 07/13/2024]
Affiliation(s)
- Uri Galili
- Department of Medicine, Rush University Medical Center, Chicago, Illinois, USA
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2
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Bender M, Reichart B, Figueiredo C, Burgmann JM, Leuschen M, Wall F, Radan J, Neumann E, Mokelke M, Buttgereit I, Michel S, Ellgass R, Egerer S, Lange A, Baehr A, Kessler B, Kemter E, Klymiuk N, Denner J, Godehardt AW, Tönjes RR, Hagl C, Gebauer M, Binder U, Skerra A, Ayares D, Wolf E, Schmoeckel M, Brenner P, Längin M, Abicht JM. An Approach to Controlling Inflammation and Coagulation in Pig-to-Baboon Cardiac Xenotransplantation. Xenotransplantation 2024; 31:e12877. [PMID: 39077824 DOI: 10.1111/xen.12877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/05/2024] [Accepted: 07/04/2024] [Indexed: 07/31/2024]
Abstract
INTRODUCTION Inflammatory responses and coagulation disorders are a relevant challenge for successful cardiac xenotransplantation on its way to the clinic. To cope with this, an effective and clinically practicable anti-inflammatory and anti-coagulatory regimen is needed. The inflammatory and coagulatory response can be reduced by genetic engineering of the organ-source pigs. Furthermore, there are several therapeutic strategies to prevent or reduce inflammatory responses and coagulation disorders following xenotransplantation. However, it is still unclear, which combination of drugs should be used in the clinical setting. To elucidate this, we present data from pig-to-baboon orthotopic cardiac xenotransplantation experiments using a combination of several anti-inflammatory drugs. METHODS Genetically modified piglets (GGTA1-KO, hCD46/hTBM transgenic) were used for orthotopic cardiac xenotransplantation into captive-bred baboons (n = 14). All animals received an anti-inflammatory drug therapy including a C1 esterase inhibitor, an IL-6 receptor antagonist, a TNF-α inhibitor, and an IL-1 receptor antagonist. As an additive medication, acetylsalicylic acid and unfractionated heparin were administered. The immunosuppressive regimen was based on CD40/CD40L co-stimulation blockade. During the experiments, leukocyte counts, levels of C-reactive protein (CRP) as well as systemic cytokine and chemokine levels and coagulation parameters were assessed at multiple timepoints. Four animals were excluded from further data analyses due to porcine cytomegalovirus/porcine roseolovirus (PCMV/PRV) infections (n = 2) or technical failures (n = 2). RESULTS Leukocyte counts showed a relevant perioperative decrease, CRP levels an increase. In the postoperative period, leukocyte counts remained consistently within normal ranges, CRP levels showed three further peaks after about 35, 50, and 80 postoperative days. Analyses of cytokines and chemokines revealed different patterns. Some cytokines, like IL-8, increased about 2-fold in the perioperative period, but then decreased to levels comparable to the preoperative values or even lower. Other cytokines, such as IL-12/IL-23, decreased in the perioperative period and stayed at these levels. Besides perioperative decreases, there were no relevant alterations observed in coagulation parameters. In summary, all parameters showed an unremarkable course with regard to inflammatory responses and coagulation disorders following cardiac xenotransplantation and thus showed the effectiveness of our approach. CONCLUSION Our preclinical experience with the anti-inflammatory drug therapy proved that controlling of inflammation and coagulation disorders in xenotransplantation is possible and well-practicable under the condition that transmission of pathogens, especially of PCMV/PRV to the recipient is prevented because PCMV/PRV also induces inflammation and coagulation disorders. Our anti-inflammatory regimen should also be applicable and effective in the clinical setting of cardiac xenotransplantation.
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Affiliation(s)
- Martin Bender
- Department of Anaesthesiology, University Hospital, LMU Munich, Munich, Germany
| | - Bruno Reichart
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Constanca Figueiredo
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
| | - Jonathan M Burgmann
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
| | - Maria Leuschen
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Felicia Wall
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Julia Radan
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Elisabeth Neumann
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Maren Mokelke
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Ines Buttgereit
- Department of Anaesthesiology, University Hospital, LMU Munich, Munich, Germany
| | - Sebastian Michel
- Department of Cardiac Surgery, University Hospital, LMU Munich, Munich, Germany
| | - Reinhard Ellgass
- Department of Cardiac Surgery, University Hospital, LMU Munich, Munich, Germany
| | - Stefanie Egerer
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Andreas Lange
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Andrea Baehr
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Barbara Kessler
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Elisabeth Kemter
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Nikolai Klymiuk
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Joachim Denner
- Institute of Virology, Free University Berlin, Berlin, Germany
| | - Antonia W Godehardt
- Division of Haematology, Cell and Gene Therapy, Paul-Ehrlich-Institut, Langen, Germany
| | - Ralf R Tönjes
- Division of Haematology, Cell and Gene Therapy, Paul-Ehrlich-Institut, Langen, Germany
| | - Christian Hagl
- Department of Cardiac Surgery, University Hospital, LMU Munich, Munich, Germany
| | | | | | - Arne Skerra
- Chair of Biological Chemistry, School of Life Sciences, Technical University of Munich, Freising, Germany
| | | | - Eckhard Wolf
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, Munich, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICONLMU), LMU Munich, Munich, Germany
| | - Michael Schmoeckel
- Department of Cardiac Surgery, University Hospital, LMU Munich, Munich, Germany
| | - Paolo Brenner
- Department of Cardiac Surgery, University Hospital, LMU Munich, Munich, Germany
| | - Matthias Längin
- Department of Anaesthesiology, University Hospital, LMU Munich, Munich, Germany
| | - Jan-Michael Abicht
- Department of Anaesthesiology, University Hospital, LMU Munich, Munich, Germany
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Manook M, Olaso D, Anwar I, DeLaura I, Yoon J, Bae Y, Barbas A, Shaw B, Moris D, Song M, Farris AB, Stiede K, Youd M, Knechtle S, Kwun J. Prolonged xenokidney graft survival in sensitized NHP recipients by expression of multiple human transgenes in a triple knockout pig. Sci Transl Med 2024; 16:eadk6152. [PMID: 38865482 PMCID: PMC11328991 DOI: 10.1126/scitranslmed.adk6152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 05/07/2024] [Indexed: 06/14/2024]
Abstract
Genetic modification of porcine donors, combined with optimized immunosuppression, has been shown to improve outcomes of experimental xenotransplant. However, little is known about outcomes in sensitized recipients, a population that could potentially benefit the most from the clinical implementation of xenotransplantation. Here, five highly allosensitized rhesus macaques received a porcine kidney from GGTA1 (α1,3-galactosyltransferase) knockout pigs expressing the human CD55 transgene (1KO.1TG) and were maintained on an anti-CD154 monoclonal antibody (mAb)-based immunosuppressive regimen. These recipients developed de novo xenoreactive antibodies and experienced xenograft rejection with evidence of thrombotic microangiopathy and antibody-mediated rejection (AMR). In comparison, three highly allosensitized rhesus macaques receiving a kidney from GGTA1, CMAH (cytidine monophospho-N-acetylneuraminic acid hydroxylase), and b4GNT2/b4GALNT2 (β-1,4-N-acetyl-galactosaminyltransferase 2) knockout pigs expressing seven human transgenes including human CD46, CD55, CD47, THBD (thrombomodulin), PROCR (protein C receptor), TNFAIP3 (tumor necrosis factor-α-induced protein 3), and HMOX1 (heme oxygenase 1) (3KO.7TG) experienced significantly prolonged graft survival and reduced AMR, associated with dampened post-transplant humoral responses, early monocyte and neutrophil activation, and T cell repopulation. After withdrawal of all immunosuppression, recipients who received kidneys from 3KO.7TG pigs rejected the xenografts via AMR. These data suggest that allosensitized recipients may be suitable candidates for xenografts from genetically modified porcine donors and could benefit from an optimized immunosuppression regimen designed to target the post-transplant humoral response, thereby avoiding AMR.
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Affiliation(s)
- Miriam Manook
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Danae Olaso
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Imran Anwar
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Isabel DeLaura
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Janghoon Yoon
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yeeun Bae
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Andrew Barbas
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Brian Shaw
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Dimitrios Moris
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mingqing Song
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Alton B Farris
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | | | - Stuart Knechtle
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Jean Kwun
- Duke Transplant Center, Duke University School of Medicine, Durham, NC 27710, USA
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4
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Cooper DKC, Kobayashi T. Xenotransplantation experiments in brain-dead human subjects-A critical appraisal. Am J Transplant 2024; 24:520-525. [PMID: 38158188 DOI: 10.1016/j.ajt.2023.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/03/2024]
Abstract
Brain-dead human subjects (decedents) were recently introduced as a potential preclinical experimental model in xenotransplantation. Brain death is associated with major pathophysiological changes, eg, structural injury and cell infiltration in vital organs, and major hormonal, metabolic, inflammatory, and hemodynamic changes. In 2 of the 3 initial experiments, the design of the experiments resulted in little or no new information becoming available. In the third, the experiment was unfortunately unsuccessful as neither of the 2 pig kidneys transplanted into the decedent functioned adequately. Failure may well have been associated with the effects of brain death, but an immune/inflammatory response to the xenograft could not be excluded. Subsequently, 2 further pig kidney transplants and 2 pig heart transplants have been carried out in human decedents, but again the data obtained do not add much to what is already known. In view of the profound changes that take place during and after brain death, it may prove difficult to determine whether graft failure or dysfunction results from the effects of brain death or from an immune/inflammatory response to the xenograft. A major concern is that, if the results are confusing, they may impact decisions relating to the introduction of clinical xenotransplantation.
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Affiliation(s)
- David K C Cooper
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA.
| | - Takaaki Kobayashi
- Department of Renal Transplant Surgery, Aichi University School of Medicine, Nagakute, Japan
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5
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Cooper DKC, Mou L, Bottino R. A brief review of the current status of pig islet xenotransplantation. Front Immunol 2024; 15:1366530. [PMID: 38464515 PMCID: PMC10920266 DOI: 10.3389/fimmu.2024.1366530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Accepted: 02/07/2024] [Indexed: 03/12/2024] Open
Abstract
An estimated 1.5 million Americans suffer from Type I diabetes mellitus, and its incidence is increasing worldwide. Islet allotransplantation offers a treatment, but the availability of deceased human donor pancreases is limited. The transplantation of islets from gene-edited pigs, if successful, would resolve this problem. Pigs are now available in which the expression of the three known xenoantigens against which humans have natural (preformed) antibodies has been deleted, and in which several human 'protective' genes have been introduced. The transplantation of neonatal pig islets has some advantages over that of adult pig islets. Transplantation into the portal vein of the recipient results in loss of many islets from the instant blood-mediated inflammatory reaction (IBMIR) and so the search for an alternative site continues. The adaptive immune response can be largely suppressed by an immunosuppressive regimen based on blockade of the CD40/CD154 T cell co-stimulation pathway, whereas conventional therapy (e.g., based on tacrolimus) is less successful. We suggest that, despite the need for effective immunosuppressive therapy, the transplantation of 'free' islets will prove more successful than that of encapsulated islets. There are data to suggest that, in the absence of rejection, the function of pig islets, though less efficient than human islets, will be sufficient to maintain normoglycemia in diabetic recipients. Pig islets transplanted into immunosuppressed nonhuman primates have maintained normoglycemia for periods extending more than two years, illustrating the potential of this novel form of therapy.
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Affiliation(s)
- David K. C. Cooper
- Center for Transplantation Sciences, Massachusetts General Hospital/Harvard Medical School, Boston, MA, United States
| | - Lisha Mou
- Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, Guangdong, China
- MetaLife Center, Shenzhen Institute of Translational Medicine, Shenzhen, Guangdong, China
| | - Rita Bottino
- Imagine Islet Center, Imagine Pharma, Pittsburgh, PA, United States
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6
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Suh HN, Lee JY, Kang HJ, Park EM, Yun IJ, Kim WS, Choi K, Hwang JH. A Comparison Between GalT-/-; hCD39;hCD55 and GalT-/-; hCD39;hCD46;hCD55;TBM Pig Kidneys Transplanted in Nonhuman Primates. Cell Transplant 2024; 33:9636897231217382. [PMID: 38229498 PMCID: PMC10798062 DOI: 10.1177/09636897231217382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 01/18/2024] Open
Abstract
Because there is a shortage of donor kidneys, researchers are exploring the possibility of using genetically modified pig kidneys for transplantation. Approaches involving knockout of carbohydrate genes or knockin of protective proteins have been attempted to determine the best gene modifications. In this study, we utilized GalT-/-;hCD39;hCD55 and GalT-/-;hCD39;hCD46;hCD55;thrombomodulin (TBM) pigs for transplantation in nonhuman primates (NHPs). The NHPs survived for 4 weeks after kidney transplantation (4 WAT) from the GalT-/-;hCD39;hCD55 pig and for 6 WAT from the GalT-/-;hCD39;hCD46;hCD55;TBM pig. However, messenger RNA (mRNA) sequencing and immunohistochemistry analysis revealed that the 6 WAT kidney exhibited more severe apoptosis, inflammation, loss of renal function, and renal fibrosis than the 4 WAT kidney. These results indicate that additional knockin of complement regulator (hCD46) and coagulation regulator (TBM) is not enough to prevent renal damage, suggesting that improved immune suppression is needed for more prolonged survival.
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Affiliation(s)
- Han Na Suh
- Animal Model Research Group, Korea Institute of Toxicology, Jeongeup, Republic of Korea
- Center for Companion Animal New Drug Development, Korea Institute of Toxicology, Jeongeup, Republic of Korea
| | - Ju Young Lee
- Animal Model Research Group, Korea Institute of Toxicology, Jeongeup, Republic of Korea
| | - Hee Jung Kang
- Department of Laboratory Medicine, Hallym University College of Medicine, Hallym University Sacred Heart Hospital, Chuncheon-si, Republic of Korea
| | - Eun Mi Park
- Department of Laboratory Medicine, Hallym University College of Medicine, Hallym University Sacred Heart Hospital, Chuncheon-si, Republic of Korea
| | - Ik Jin Yun
- Department of Surgery, School of Medicine, Konkuk University, Seoul, Korea
| | - Wan Seop Kim
- Department of Pathology, School of Medicine, Konkuk University, Seoul, Korea
| | - Kimyung Choi
- Department of Transgenic Animal Research, Optipharm Inc, Cheongju-si, Republic of Korea
| | - Jeong Ho Hwang
- Animal Model Research Group, Korea Institute of Toxicology, Jeongeup, Republic of Korea
- Center for Companion Animal New Drug Development, Korea Institute of Toxicology, Jeongeup, Republic of Korea
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7
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Cooper DKC, Raza SS, Chaban R, Pierson RN. Shooting for the moon: Genome editing for pig heart xenotransplantation. J Thorac Cardiovasc Surg 2023; 166:973-980. [PMID: 35659123 PMCID: PMC10124774 DOI: 10.1016/j.jtcvs.2022.04.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 04/04/2022] [Accepted: 04/16/2022] [Indexed: 10/18/2022]
Abstract
Gene-edited pigs could eventually provide organs that are safely and effectively protected from the human immune response without exogenous immunosuppression. Genome editing technology has revolutionized heart xenotransplantation and made transplantation of bioengineered pig hearts into humans a possibility. This first clinical application resulted from a tremendous amount of research. Dramatic early attempts of clinical cardiac xenotransplantation during the last century paved the way to modern xenotransplantation using bioengineered pig hearts. It appears that such genome-edited hearts will be most suitable for neonates and infants because of their immature immune system. The bioengineered pig heart may also be used as a bridge to human heart transplantation, avoiding the risk of thromboembolic events of durable ventricular assist devises in these young children. It is also intriguing to think that bioengineered hearts using pigs as a host may result in a new source of donor hearts that would not evoke the human immune response and minimize, if not eliminate, the need for immunosuppression. It this issue of the Journal, a group of experts led by Dr Cooper, whose personal work spans over 50 years of heart transplantation research, outline the current state of the genome editing of bioengineered hearts and discuss the prospects of clinical application.
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Affiliation(s)
- David K C Cooper
- Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, Mass
| | | | - Ryan Chaban
- Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, Mass; Department of Cardiovascular Surgery, University Hospital of Johannes Gutenberg University, Mainz, Germany.
| | - Richard N Pierson
- Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, Mass
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8
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Konstantinov IE, Cooper DKC, Adachi I, Bacha E, Bleiweis MS, Chinnock R, Cleveland D, Cowan PJ, Fynn-Thompson F, Morales DLS, Mohiuddin MM, Reichart B, Rothblatt M, Roy N, Turek JW, Urschel S, West L, Wolf E. Consensus statement on heart xenotransplantation in children: Toward clinical translation. J Thorac Cardiovasc Surg 2023; 166:960-967. [PMID: 36184321 PMCID: PMC10124772 DOI: 10.1016/j.jtcvs.2022.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 09/01/2022] [Indexed: 10/14/2022]
Affiliation(s)
- Igor E Konstantinov
- Royal Children's Hospital, University of Melbourne, Murdoch Children's Research Institute, Melbourne Centre for Cardiovascular Genomics and Regenerative Medicine, Melbourne, Australia.
| | - David K C Cooper
- Center for Transplantation Sciences, Massachusetts General Hospital/Harvard Medical School, Boston, Mass
| | - Iki Adachi
- Texas Children's Hospital, Baylor College of Medicine, Houston, Tex
| | - Emile Bacha
- Columbia University Medical Center, Morgan Stanley Children's Hospital, New York, NY
| | | | | | - David Cleveland
- Department of Surgery, University of Alabama, Birmingham, Ala
| | - Peter J Cowan
- Immunology Research Centre, St. Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | | | - David L S Morales
- Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Muhammad M Mohiuddin
- Program in Cardiac Xenotransplantation, University of Maryland School of Medicine, Baltimore, Md
| | - Bruno Reichart
- Transregional Collaborative Research Center, Walter Brendel Centre of Experimental Medicine, Ludwig Maximilians University, Munich, Germany
| | | | - Nathalie Roy
- Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Joseph W Turek
- Department of Surgery, Duke University Medical Center, Durham, NC
| | - Simon Urschel
- Pediatric Cardiac Transplantation Program, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Lori West
- Pediatric Cardiac Transplantation Program, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada; Canadian Donation and Transplantation Research Program, Alberta Transplant Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Eckhard Wolf
- Gene Center and Department of Veterinary Sciences, Ludwig Maximilians University, Munich, Germany
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Cooper DK, Hara H. Xenotransplantation-A Basic Science Perspective. KIDNEY360 2023; 4:1147-1149. [PMID: 37265370 PMCID: PMC10476676 DOI: 10.34067/kid.0000000000000173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 05/03/2023] [Indexed: 06/03/2023]
Affiliation(s)
- David K.C. Cooper
- Center for Transplantation Sciences, Department of Surgery, General Hospital/Harvard Medical School, Boston, Massachusetts
| | - Hidetaka Hara
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
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10
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Hess NR, Kaczorowski DJ. The history of cardiac xenotransplantation: early attempts, major advances, and current progress. FRONTIERS IN TRANSPLANTATION 2023; 2:1125047. [PMID: 38993853 PMCID: PMC11235224 DOI: 10.3389/frtra.2023.1125047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 05/16/2023] [Indexed: 07/13/2024]
Abstract
In light of ongoing shortage of donor organs for transplantation, alternative sources for donor organ sources have been examined to address this supply-demand mismatch. Of these, xenotransplantation, or the transplantation of organs across species, has been considered, with early applications dating back to the 1600s. The purpose of this review is to summarize the early experiences of xenotransplantation, with special focus on heart xenotransplantation. It aims to highlight the important ethical concerns of animal-to-human heart xenotransplantation, identify the key immunological barriers to successful long-term xenograft survival, as well as summarize the progress made in terms of development of pharmacological and genetic engineering strategies to address these barriers. Lastly, we discuss more recent attempts of porcine-to-human heart xenotransplantation, as well as provide some commentary on the current concerns and possible applications for future clinical heart xenotransplantation.
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Affiliation(s)
- Nicholas R. Hess
- Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - David J. Kaczorowski
- Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- University of Pittsburgh Medical Center Heart and Vascular Institute, Pittsburgh, PA, United States
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11
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Singh AK, Goerlich CE, Zhang T, Lewis BG, Hershfeld A, Mohiuddin MM. CD40-CD40L Blockade: Update on Novel Investigational Therapeutics for Transplantation. Transplantation 2023; 107:1472-1481. [PMID: 36584382 PMCID: PMC10287837 DOI: 10.1097/tp.0000000000004469] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Effective immune responses require antigen presentation by major histocompatibility complexes with cognate T-cell receptor and antigen-independent costimulatory signaling for T-cell activation, proliferation, and differentiation. Among several costimulatory signals, CD40-CD40L is of special interest to the transplantation community because it plays a vital role in controlling or regulating humoral and cellular immunity. Blockade of this pathway has demonstrated inhibition of donor-reactive T-cell responses and prolonged the survival of transplanted organs. Several anti-CD154 and anti-CD40 antibodies have been used in the transplantation model and demonstrated the potential of extending allograft and xenograft rejection-free survival. The wide use of anti-CD154 antibodies was hampered because of thromboembolic complications in transplant recipients. These antibodies have been modified to overcome the thromboembolic complications by altering the antibody binding fragment (Fab) and Fc (fragment, crystallizable) receptor region for therapeutic purposes. Here, we review recent preclinical advances to target the CD40-CD40L pair in transplantation.
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Affiliation(s)
| | | | - Tianshu Zhang
- University of Maryland School of Medicine, Baltimore, MD
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12
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Hara H, Yamamoto T, Wei HJ, Cooper DK. What Have We Learned From In Vitro Studies About Pig-to-primate Organ Transplantation? Transplantation 2023; 107:1265-1277. [PMID: 36536507 PMCID: PMC10205677 DOI: 10.1097/tp.0000000000004458] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Natural preformed and de novo antibodies against pig antigens are a major cause of pig xenograft rejection in nonhuman primates (NHPs). In vivo studies in pig-to-NHP models are time consuming. In vitro assays, for example, antibody binding to pig cells, complement-dependent cytotoxicity assays, provide valuable information quickly and inexpensively. Using in vitro assays for several years, it has been documented that (1) during the first year of life, humans and NHPs develop anti-wild-type pig antibodies, but humans develop no or minimal antibody to triple-knockout (TKO) pig cells. (2) Some adult humans have no or minimal antibodies to TKO pig cells and are therefore unlikely to rapidly reject a TKO organ, particularly if the organ also expresses human "protective" proteins. (3) There is good correlation between immunoglobulin (Ig)M (but no t IgG) binding and complement injury. (4) All Old World NHPs develop antibodies to TKO pig cells and are not optimal recipients of TKO organs. (5) galactosyltransferase gene-knockout/β4GalNT2KO pigs are preferred for Old World NHPs. (6) Humans develop anti-pig IgE and IgA antibodies against pig cells, but their role remains uncertain. (7) In a small percentage of allosensitized humans, antibodies that cross-react with swine leukocyte antigens may be detrimental to a pig organ xenograft. (8) Prior sensitization to pig antigens is unlikely to be detrimental to a subsequent allograft. (9) Deletion of expression of Gal and Neu5Gc is associated with a reduction in the T-cell response to pig cells. All of these valuable observations have largely predicted the results of in vivo studies.
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Affiliation(s)
- Hidetaka Hara
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Takayuki Yamamoto
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital/Harvard Medical School, Boston, MA
| | - Hong-Jiang Wei
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan, China
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, China
| | - David K.C. Cooper
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital/Harvard Medical School, Boston, MA
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13
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Koh J, Chee HK, Kim KH, Jeong IS, Kim JS, Lee CH, Seo JW. Historical Review and Future of Cardiac Xenotransplantation. Korean Circ J 2023; 53:351-366. [PMID: 37271743 DOI: 10.4070/kcj.2022.0351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/14/2023] [Accepted: 04/05/2023] [Indexed: 06/06/2023] Open
Abstract
Along with the development of immunosuppressive drugs, major advances on xenotransplantation were achieved by understanding the immunobiology of xenograft rejection. Most importantly, three predominant carbohydrate antigens on porcine endothelial cells were key elements provoking hyperacute rejection: α1,3-galactose, SDa blood group antigen, and N-glycolylneuraminic acid. Preformed antibodies binding to the porcine major xenoantigen causes complement activation and endothelial cell activation, leading to xenograft injury and intravascular thrombosis. Recent advances in genetic engineering enabled knock-outs of these major xenoantigens, thus producing xenografts with less hyperacute rejection rates. Another milestone in the history of xenotransplantation was the development of co-stimulation blockaded strategy. Unlike allotransplantation, xenotransplantation requires blockade of CD40-CD40L pathway to prevent T-cell dependent B-cell activation and antibody production. In 2010s, advanced genetic engineering of xenograft by inducing the expression of multiple human transgenes became available. So-called 'multi-gene' xenografts expressing human transgenes such as thrombomodulin and endothelial protein C receptor were introduced, which resulted in the reduction of thrombotic events and improvement of xenograft survival. Still, there are many limitations to clinical translation of cardiac xenotransplantation. Along with technical challenges, zoonotic infection and physiological discordances are major obstacles. Social barriers including healthcare costs also need to be addressed. Although there are several remaining obstacles to overcome, xenotransplantation would surely become the novel option for millions of patients with end-stage heart failure who have limited options to traditional therapeutics.
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Affiliation(s)
- Jiwon Koh
- Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Hyun Keun Chee
- Department of Thoracic and Cardiovascular Surgery, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
| | - Kyung-Hee Kim
- Division of Cardiology, Incheon Sejong Hospital, Incheon, Korea
| | - In-Seok Jeong
- Department of Thoracic and Cardiovascular Surgery, Chonnam National University Hospital and Medical School, Gwangju, Korea
| | - Jung-Sun Kim
- Department of Pathology and Translational Genomics, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea
| | - Chang-Ha Lee
- Department of Thoracic and Cardiovascular Surgery, Bucheon Sejong Hospital, Bucheon, Korea
| | - Jeong-Wook Seo
- Department of Pathology, Incheon Sejong Hospital, Incheon, Korea.
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14
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Hwang SA, Park KS, Kim WS, Shin KC, Ahn YR, Kim JS, Chee HK, Yang HS, Oh KB, Choi KM, Hwang JH, Hur CG, Yun IJ. Current Status of Genetically Engineered Pig to Monkey Kidney Xenotransplantation in Korea. Transplant Proc 2023:S0041-1345(23)00225-7. [PMID: 37179178 DOI: 10.1016/j.transproceed.2023.03.060] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 03/28/2023] [Indexed: 05/15/2023]
Abstract
BACKGROUND In South Korea, pig-to-nonhuman primate trials of solid organs have only been performed recently, and the results are not sufficiently satisfactory to initiate clinical trials. Since November 2011, we have performed 30 kidney pig-to-nonhuman primate xenotransplantations at Konkuk University Hospital. METHODS Donor αGal-knockout-based transgenic pigs were obtained from 3 institutes. The knock-in genes were CD39, CD46, CD55, CD73, and thrombomodulin, and 2-4 transgenic modifications with GTKO were done. The recipient animal was the cynomolgus monkey. We used the immunosuppressants anti-CD154, rituximab, anti-thymocyte globulin, tacrolimus, mycophenolate mofetil, and steroids. RESULTS The mean survival duration of the recipients was 39 days. Except for a few cases for which survival durations were <2 days because of technical failure, 24 grafts survived for >7 days, with an average survival duration of 50 days. Long-term survival was observed 115 days after the removal of the contralateral kidney, which is currently the longest-recorded graft survival in Korea. We confirmed functioning grafts for the surviving transplanted kidneys after the second-look operation, and no signs of hyperacute rejection were observed. CONCLUSIONS Although our survival results are relatively poor, they are the best-recorded results in South Korea, and the ongoing results are improving. With the support of government funds and the volunteering activities of clinical experts, we aim to further improve our experiments and contribute to the commencement of clinical trials of kidney xenotransplantation in Korea.
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Affiliation(s)
- Sun Ae Hwang
- Department of Surgery, Konkuk University School of Medicine, Seoul, Korea
| | - Kyoung Sik Park
- Department of Surgery, Konkuk University School of Medicine, Seoul, Korea
| | - Wan Seop Kim
- Department of Pathology, Konkuk University School of Medicine, Seoul, Korea
| | - Ki Cheul Shin
- Department of Ophthalmology, Konkuk University Medical Center, Seoul, Korea
| | - Yu Rim Ahn
- Department of Surgery, Konkuk University School of Medicine, Seoul, Korea
| | - Jun Seok Kim
- Department of Thoracic and Cardiovascular Surgery, Konkuk University School of Medicine, Seoul, Korea
| | - Hyun Keun Chee
- Department of Thoracic and Cardiovascular Surgery, Konkuk University School of Medicine, Seoul, Korea
| | - Hyun Suk Yang
- Department of Cardiology, Konkuk University School of Medicine, Seoul, Korea
| | - Keon Bong Oh
- Animal Biotechnology Division, National Institute of Animal Science, Wanju-gun, Korea
| | - Ki Myung Choi
- Department of Transgenic Animal Research, Optipharm, Inc., Cheongju-si, Republic of Korea
| | - Jeong Ho Hwang
- Non-Human Primate Minipig Translational Toxicology Research, Korea Institute of Toxicology, Jeonbuk, Korea
| | | | - Ik Jin Yun
- Department of Surgery, Konkuk University School of Medicine, Seoul, Korea.
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15
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Tseng HT, Lin YW, Huang CY, Shih CM, Tsai YT, Liu CW, Tsai CS, Lin FY. Animal Models for Heart Transplantation Focusing on the Pathological Conditions. Biomedicines 2023; 11:biomedicines11051414. [PMID: 37239085 DOI: 10.3390/biomedicines11051414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/29/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
Cardiac transplant recipients face many complications due to transplant rejection. Scientists must conduct animal experiments to study disease onset mechanisms and develop countermeasures. Therefore, many animal models have been developed for research topics including immunopathology of graft rejection, immunosuppressive therapies, anastomotic techniques, and graft preservation techniques. Small experimental animals include rodents, rabbits, and guinea pigs. They have a high metabolic rate, high reproductive rate, small size for easy handling, and low cost. Additionally, they have genetically modified strains for pathological mechanisms research; however, there is a lacuna, as these research results rarely translate directly to clinical applications. Large animals, including canines, pigs, and non-human primates, have anatomical structures and physiological states that are similar to those of humans; therefore, they are often used to validate the results obtained from small animal studies and directly speculate on the feasibility of applying these results in clinical practice. Before 2023, PubMed Central® at the United States National Institute of Health's National Library of Medicine was used for literature searches on the animal models for heart transplantation focusing on the pathological conditions. Unpublished reports and abstracts from conferences were excluded from this review article. We discussed the applications of small- and large-animal models in heart transplantation-related studies. This review article aimed to provide researchers with a complete understanding of animal models for heart transplantation by focusing on the pathological conditions created by each model.
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Affiliation(s)
- Horng-Ta Tseng
- Taipei Heart Institute, Taipei Medical University, Taipei 11031, Taiwan
- Division of Cardiology and Cardiovascular Research Center, Taipei Medical University Hospital, Taipei 11031, Taiwan
- Departments of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
| | - Yi-Wen Lin
- Institute of Oral Biology, National Yang Ming Chiao Tung University (Yangming Campus), Taipei 112304, Taiwan
| | - Chun-Yao Huang
- Taipei Heart Institute, Taipei Medical University, Taipei 11031, Taiwan
- Division of Cardiology and Cardiovascular Research Center, Taipei Medical University Hospital, Taipei 11031, Taiwan
- Departments of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
| | - Chun-Ming Shih
- Taipei Heart Institute, Taipei Medical University, Taipei 11031, Taiwan
- Division of Cardiology and Cardiovascular Research Center, Taipei Medical University Hospital, Taipei 11031, Taiwan
- Departments of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
| | - Yi-Ting Tsai
- Division of Cardiovascular Surgery, Tri-Service General Hospital, Defense Medical Center, Taipei 11490, Taiwan
| | - Chen-Wei Liu
- Department of Basic Medical Science, College of Medicine, University of Arizona, Phoenix, AZ 85721, USA
| | - Chien-Sung Tsai
- Taipei Heart Institute, Taipei Medical University, Taipei 11031, Taiwan
- Division of Cardiovascular Surgery, Tri-Service General Hospital, Defense Medical Center, Taipei 11490, Taiwan
- Department and Graduate Institute of Pharmacology, National Defense Medical Center, Taipei 11490, Taiwan
| | - Feng-Yen Lin
- Taipei Heart Institute, Taipei Medical University, Taipei 11031, Taiwan
- Division of Cardiology and Cardiovascular Research Center, Taipei Medical University Hospital, Taipei 11031, Taiwan
- Departments of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
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16
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Cooper DKC, Pierson RN. Milestones on the path to clinical pig organ xenotransplantation. Am J Transplant 2023; 23:326-335. [PMID: 36775767 PMCID: PMC10127379 DOI: 10.1016/j.ajt.2022.12.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/19/2023]
Abstract
Progress in pig organ xenotransplantation has been made largely through (1) genetic engineering of the organ-source pig to protect its tissues from the human innate immune response, and (2) development of an immunosuppressive regimen based on blockade of the CD40/CD154 costimulation pathway to prevent the adaptive immune response. In the 1980s, after transplantation into nonhuman primates (NHPs), wild-type (genetically unmodified) pig organs were rejected within minutes or hours. In the 1990s, organs from pigs expressing a human complement-regulatory protein (CD55) transplanted into NHPs receiving intensive conventional immunosuppressive therapy functioned for days or weeks. When costimulation blockade was introduced in 2000, the adaptive immune response was suppressed more readily. The identification of galactose-α1,3-galactose as the major antigen target for human and NHP anti-pig antibodies in 1991 allowed for deletion of expression of galactose-α1,3-galactose in 2003, extending pig graft survival for up to 6 months. Subsequent gene editing to overcome molecular incompatibilities between the pig and primate coagulation systems proved additionally beneficial. The identification of 2 further pig carbohydrate xenoantigens allowed the production of 'triple-knockout' pigs that are preferred for clinical organ transplantation. These combined advances enabled the first clinical pig heart transplant to be performed and opened the door to formal clinical trials.
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Affiliation(s)
- David K C Cooper
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA.
| | - Richard N Pierson
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
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17
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Lei T, Chen L, Wang K, Du S, Gonelle-Gispert C, Wang Y, Buhler LH. Genetic engineering of pigs for xenotransplantation to overcome immune rejection and physiological incompatibilities: The first clinical steps. Front Immunol 2022; 13:1031185. [PMID: 36561750 PMCID: PMC9766364 DOI: 10.3389/fimmu.2022.1031185] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022] Open
Abstract
Xenotransplantation has the potential to solve the shortfall of human organ donors. Genetically modified pigs have been considered as potential animal donors for human xenotransplantation and have been widely used in preclinical research. The genetic modifications aim to prevent the major species-specific barriers, which include humoral and cellular immune responses, and physiological incompatibilities such as complement and coagulation dysfunctions. Genetically modified pigs can be created by deleting several pig genes related to the synthesis of various pig specific antigens or by inserting human complement- and coagulation-regulatory transgenes. Finally, in order to reduce the risk of infection, genes related to porcine endogenous retroviruses can be knocked down. In this review, we focus on genetically modified pigs and comprehensively summarize the immunological mechanism of xenograft rejection and recent progress in preclinical and clinical studies. Overall, both genetically engineered pig-based xenografts and technological breakthroughs in the biomedical field provide a promising foundation for pig-to-human xenotransplantation in the future.
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Affiliation(s)
- Tiantian Lei
- Department of Pharmacy, Women and Children’s Hospital of Chongqing Medical University, Chongqing Health Center for Women and Children, Chongqing, China
| | - Lin Chen
- Department of Pharmacy, Women and Children’s Hospital of Chongqing Medical University, Chongqing Health Center for Women and Children, Chongqing, China
| | - Kejing Wang
- Department of Pharmacy, Women and Children’s Hospital of Chongqing Medical University, Chongqing Health Center for Women and Children, Chongqing, China
| | - Suya Du
- Department of Clinical Pharmacy, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Sichuan, China
| | - Carmen Gonelle-Gispert
- Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland,*Correspondence: Carmen Gonelle-Gispert, ; Yi Wang, ; Leo H. Buhler,
| | - Yi Wang
- Department of Critical Care Medicine, Sichuan Academy of Medical Science and Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China,*Correspondence: Carmen Gonelle-Gispert, ; Yi Wang, ; Leo H. Buhler,
| | - Leo H. Buhler
- Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland,*Correspondence: Carmen Gonelle-Gispert, ; Yi Wang, ; Leo H. Buhler,
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18
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Lu TY, Xu XL, Du XG, Wei JH, Yu JN, Deng SL, Qin C. Advances in Innate Immunity to Overcome Immune Rejection during Xenotransplantation. Cells 2022; 11:cells11233865. [PMID: 36497122 PMCID: PMC9735653 DOI: 10.3390/cells11233865] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
Transplantation is an effective approach for treating end-stage organ failure. There has been a long-standing interest in xenotransplantation as a means of increasing the number of available organs. In the past decade, there has been tremendous progress in xenotransplantation accelerated by the development of rapid gene-editing tools and immunosuppressive therapy. Recently, the heart and kidney from pigs were transplanted into the recipients, which suggests that xenotransplantation has entered a new era. The genetic discrepancy and molecular incompatibility between pigs and primates results in barriers to xenotransplantation. An increasing body of evidence suggests that innate immune responses play an important role in all aspects of the xenogeneic rejection. Simultaneously, the role of important cellular components like macrophages, natural killer (NK) cells, and neutrophils, suggests that the innate immune response in the xenogeneic rejection should not be underestimated. Here, we summarize the current knowledge about the innate immune system in xenotransplantation and highlight the key issues for future investigations. A better understanding of the innate immune responses in xenotransplantation may help to control the xenograft rejection and design optimal combination therapies.
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Affiliation(s)
- Tian-Yu Lu
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, National Human Diseases Animal Model Resource Center, Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, International Center for Technology and Innovation of animal model, Beijing 100021, China
| | - Xue-Ling Xu
- National Engineering Laboratory of Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Xu-Guang Du
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jin-Hua Wei
- Cardiovascular Surgery Department, Center of Laboratory Medicine, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Jia-Nan Yu
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, National Human Diseases Animal Model Resource Center, Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, International Center for Technology and Innovation of animal model, Beijing 100021, China
| | - Shou-Long Deng
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, National Human Diseases Animal Model Resource Center, Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, International Center for Technology and Innovation of animal model, Beijing 100021, China
- Correspondence: (S.-L.D.); (C.Q.)
| | - Chuan Qin
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, National Human Diseases Animal Model Resource Center, Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, International Center for Technology and Innovation of animal model, Beijing 100021, China
- Changping National Laboratory (CPNL), Beijing 102206, China
- Correspondence: (S.-L.D.); (C.Q.)
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19
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Eisenson DL, Hisadome Y, Santillan MR, Yamada K. Progress in islet xenotransplantation: Immunologic barriers, advances in gene editing, and tolerance induction strategies for xenogeneic islets in pig-to-primate transplantation. FRONTIERS IN TRANSPLANTATION 2022; 1:989811. [PMID: 38390384 PMCID: PMC10883655 DOI: 10.3389/frtra.2022.989811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Islet transplantation has emerged as a curative therapy for diabetes in select patients but remains rare due to shortage of suitable donor pancreases. Islet transplantation using porcine islets has long been proposed as a solution to this organ shortage. There have already been several small clinical trials using porcine islets in humans, but results have been mixed and further trials limited by calls for more rigorous pre-clinical data. Recent progress in heart and kidney xenograft transplant, including three studies of pig-to-human xenograft transplant, have recaptured popular imagination and renewed interest in clinical islet xenotransplantation. This review outlines immunologic barriers to islet transplantation, summarizes current strategies to overcome these barriers with a particular focus on approaches to induce tolerance, and describes an innovative strategy for treatment of diabetic nephropathy with composite islet-kidney transplantation.
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Affiliation(s)
- Daniel L Eisenson
- Department of Surgery, The Johns Hopkins Hospital, Baltimore, MD, United States
| | - Yu Hisadome
- Department of Surgery, The Johns Hopkins Hospital, Baltimore, MD, United States
| | | | - Kazuhiko Yamada
- Department of Surgery, The Johns Hopkins Hospital, Baltimore, MD, United States
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20
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Groth T, Stegmayr BG, Ash SR, Kuchinka J, Wieringa FP, Fissell WH, Roy S. Wearable and implantable artificial kidney devices for end-stage kidney disease treatment-Current status and review. Artif Organs 2022; 47:649-666. [PMID: 36129158 DOI: 10.1111/aor.14396] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/17/2022] [Accepted: 08/24/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Chronic kidney disease (CKD) is a major cause of early death worldwide. By 2030, 14.5 million people will have end-stage kidney disease (ESKD, or CKD stage 5), yet only 5.4 million will receive kidney replacement therapy (KRT) due to economic, social, and political factors. Even for those who are offered KRT by various means of dialysis, the life expectancy remains far too low. OBSERVATION Researchers from different fields of artificial organs collaborate to overcome the challenges of creating products such as Wearable and/or Implantable Artificial Kidneys capable of providing long-term effective physiologic kidney functions such as removal of uremic toxins, electrolyte homeostasis, and fluid regulation. A focus should be to develop easily accessible, safe, and inexpensive KRT options that enable a good quality of life and will also be available for patients in less-developed regions of the world. CONCLUSIONS Hence, it is required to discuss some of the limits and burdens of transplantation and different techniques of dialysis, including those performed at home. Furthermore, hurdles must be considered and overcome to develop wearable and implantable artificial kidney devices that can help to improve the quality of life and life expectancy of patients with CKD.
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Affiliation(s)
- Thomas Groth
- Department Biomedical Materials, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.,International Federation for Artificial Organs, Painesville, Ohio, USA
| | - Bernd G Stegmayr
- Department of Public Health and Clinical Medicine, Umea University, Umea, Sweden
| | | | - Janna Kuchinka
- Department Biomedical Materials, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Fokko P Wieringa
- IMEC, Eindhoven, The Netherlands.,Department of Nephrology, University Medical Centre, Utrecht, The Netherlands.,European Kidney Health Alliance, WG3 "Breakthrough Innovation", Brussels, Belgium
| | | | - Shuvo Roy
- University of California, California, San Francisco, USA
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21
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Cooper DK. Advancing Xenotransplantation to the Clinic: How Relevant Is the Pig-to-nonhuman Primate Kidney Transplantation Model Today? Transplantation 2022; 106:1717-1719. [PMID: 35323162 PMCID: PMC10124766 DOI: 10.1097/tp.0000000000004097] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- David K.C. Cooper
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital, Boston, MA
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22
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Raza SS, Hara H, Cleveland DC, Cooper DKC. The potential of genetically engineered pig heart transplantation in infants with complex congenital heart disease. Pediatr Transplant 2022; 26:e14260. [PMID: 35233893 PMCID: PMC10124767 DOI: 10.1111/petr.14260] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 02/15/2022] [Accepted: 02/16/2022] [Indexed: 12/16/2022]
Abstract
Despite advances in surgical and medical techniques, complex congenital heart disease in neonates and infants continues to be associated with significant mortality and morbidity. More than 500 infants in the USA are placed on the cardiac transplantation wait-list annually. However, there remains a critical shortage of deceased human donor organs for transplantation with a median wait-time of 4 months. Hence, infant mortality on the heart transplant wait-list in the USA is higher than for any other solid organ transplant group. Orthotopic transplantation of a pig heart as a bridge to allotransplantation might offer the best prospect of long-term survival of these patients. In recent years, there have been several advances in genetic engineering of pigs to mitigate the vigorous antibody-mediated rejection of a pig heart transplanted into a nonhuman primate. In this review, we briefly highlight (i) the history of clinical heart xenotransplantation, (ii) current advances and techniques of genetically engineering pigs, (iii) the current status of pig orthotopic cardiac graft survival in nonhuman primates, and (iv) progress toward pursuing clinical trials of cardiac xenotransplantation. Ultimately, we argue that pig heart xenotransplantation should initially be used as a bridge to cardiac allotransplantation in neonates and infants.
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Affiliation(s)
- Syed Sikandar Raza
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David C Cleveland
- Department of Cardiothoracic Surgery, Children's of Alabama, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
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23
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Goerlich CE, Singh AK, Griffith BP, Mohiuddin MM. The immunobiology and clinical use of genetically engineered porcine hearts for cardiac xenotransplantation. NATURE CARDIOVASCULAR RESEARCH 2022; 1:715-726. [PMID: 36895262 PMCID: PMC9994617 DOI: 10.1038/s44161-022-00112-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A summary of the scientific rationale of the advancements that led to the first genetically modified pig-to-human cardiac xenotransplantation is lacking in a complex and rapidly evolving field. Here, we aim to aid the general readership in the understanding of the gradual progression of cardiac (xeno)transplantation research, the immunobiology of cardiac xenotransplantation (including the latest immunosuppression, cardiac preservation and genetic engineering required for successful transplantation) and the regulatory landscape related to the clinical application of cardiac xenotransplantation for people with end-stage heart failure. Finally, we provide an overview of the outcomes and lessons learned from the first genetically modified pig-to-human cardiac heart xenotransplantation.
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Affiliation(s)
- Corbin E Goerlich
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Avneesh K Singh
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bartley P Griffith
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Muhammad M Mohiuddin
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
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24
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Zhou Q, Li T, Wang K, Zhang Q, Geng Z, Deng S, Cheng C, Wang Y. Current status of xenotransplantation research and the strategies for preventing xenograft rejection. Front Immunol 2022; 13:928173. [PMID: 35967435 PMCID: PMC9367636 DOI: 10.3389/fimmu.2022.928173] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/07/2022] [Indexed: 12/13/2022] Open
Abstract
Transplantation is often the last resort for end-stage organ failures, e.g., kidney, liver, heart, lung, and pancreas. The shortage of donor organs is the main limiting factor for successful transplantation in humans. Except living donations, other alternatives are needed, e.g., xenotransplantation of pig organs. However, immune rejection remains the major challenge to overcome in xenotransplantation. There are three different xenogeneic types of rejections, based on the responses and mechanisms involved. It includes hyperacute rejection (HAR), delayed xenograft rejection (DXR) and chronic rejection. DXR, sometimes involves acute humoral xenograft rejection (AHR) and cellular xenograft rejection (CXR), which cannot be strictly distinguished from each other in pathological process. In this review, we comprehensively discussed the mechanism of these immunological rejections and summarized the strategies for preventing them, such as generation of gene knock out donors by different genome editing tools and the use of immunosuppressive regimens. We also addressed organ-specific barriers and challenges needed to pave the way for clinical xenotransplantation. Taken together, this information will benefit the current immunological research in the field of xenotransplantation.
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Affiliation(s)
- Qiao Zhou
- Department of Rheumatology and Immunology, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Clinical Immunology Translational Medicine Key Laboratory of Sichuan Province, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Ting Li
- Department of Rheumatology, Wenjiang District People’s Hospital, Chengdu, China
| | - Kaiwen Wang
- School of Medicine, Faculty of Medicine and Health, The University of Leeds, Leeds, United Kingdom
| | - Qi Zhang
- School of Medicine, University of Electronics and Technology of China, Chengdu, China
| | - Zhuowen Geng
- School of Medicine, Faculty of Medicine and Health, The University of Leeds, Leeds, United Kingdom
| | - Shaoping Deng
- Clinical Immunology Translational Medicine Key Laboratory of Sichuan Province, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
- Institute of Organ Transplantation, Sichuan Academy of Medical Science and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Chunming Cheng
- Department of Radiation Oncology, James Comprehensive Cancer Center and College of Medicine at The Ohio State University, Columbus, OH, United States
- *Correspondence: Chunming Cheng, ; Yi Wang,
| | - Yi Wang
- Department of Critical Care Medicine, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, Chengdu, China
- *Correspondence: Chunming Cheng, ; Yi Wang,
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Hansen-Estruch C, Porrett PM, Kumar V, Locke JE. The science of xenotransplantation for nephrologists. Curr Opin Nephrol Hypertens 2022; 31:387-393. [PMID: 35703221 DOI: 10.1097/mnh.0000000000000800] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PURPOSE OF REVIEW The field of xenotransplantation has seen remarkable progress since its inception with recent preclinical trials in human recipients pushing kidney xenotransplantation one-step closer to clinical reality. In this review, we update practicing clinicians on recent advances in kidney xenotransplantation given the proximity of clinical trials in humans. RECENT FINDINGS Early studies in the field established the physiologic basis of xenotransplantation and suggested that the pig kidney will support human physiology. Genetic engineering of source pigs has greatly reduced the immunogenicity of kidney grafts, and studies in nonhuman primates have demonstrated the viability of kidney xenotransplants for months after transplantation. Finally, a recent study in a novel preclinical human model demonstrated that key findings in NHP experiments are generalizable to humans, namely, the absence of hyperacute rejection. SUMMARY Overall, it appears that critical physiologic, immunologic and technical barriers to implementation of clinical trials in humans have been overcome.
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Affiliation(s)
| | - Paige M Porrett
- Comprehensive Transplant Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Vineeta Kumar
- Comprehensive Transplant Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jayme E Locke
- Comprehensive Transplant Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
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26
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Affiliation(s)
- David K C Cooper
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Richard N Pierson
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Jagdale A, Nguyen H, Iwase H, Foote JB, Yamamoto T, Javed M, Ayares D, Anderson DJ, Eckhoff DE, Cooper DKC, Hara H. T and B lymphocyte dynamics after genetically-modified pig-to-baboon kidney xenotransplantation with an anti-CD40mAb-based immunosuppressive regimen. Transpl Immunol 2022; 71:101545. [PMID: 35114360 PMCID: PMC9395207 DOI: 10.1016/j.trim.2022.101545] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 01/25/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND The aim was to monitor recovery of T/B lymphocytes in baboons after depletion by anti-thymocyte globulin (ATG) and anti-CD20mAb (Rituximab), followed by pig kidney transplantation and maintenance therapy with an anti-CD40mAb-based regimen. METHODS In baboons (n = 14), induction was with ATG and anti-CD20mAb, and maintenance with (i) anti-CD40mAb, (ii) rapamycin, and (iii) methylprednisolone. Follow-up was for 6 months, or until rejection or other complication developed. Baboon blood was collected at intervals to measure T/B cells and subsets by flow cytometry. In a separate study in baboons receiving the same immunosuppressive regimen (n = 10), the populations of T/B lymphocytes in PBMCs, lymph nodes, and spleen were examined. RESULTS After induction therapy, the total lymphocyte count and the absolute numbers of CD3+, CD4+, and CD8+T cells fell by >80%, and no CD22+B cells remained (all p < 0.001). T cell numbers began to recover early, but no CD22+B cells were present in the blood for 2 months. Recovery of both T and B cells remained at <30% of baseline (p < 0.001), even if rejection developed. At 6 months, effector memory CD8+T cells had increased more than other T cell subsets, but a greater percentage of B cells were naïve. In contrast to blood and spleen, T and B cells were not depleted in lymph nodes. CONCLUSIONS ATG and anti-CD20mAb effectively decreased T and B lymphocytes in the blood and, in the presence of anti-CD40mAb maintenance therapy, recovery of these cells was inhibited. The recovery of effector memory CD8+T cells may be detrimental to long-term graft survival.
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Affiliation(s)
- Abhijit Jagdale
- Department of Surgery, University of Alabama at Birmingham, AL, USA
| | - Huy Nguyen
- Department of Surgery, University of Alabama at Birmingham, AL, USA
| | - Hayato Iwase
- Department of Surgery, University of Alabama at Birmingham, AL, USA
| | - Jeremy B Foote
- Department of Microbiology and Animal Resources Program, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Mariyam Javed
- Department of Surgery, University of Alabama at Birmingham, AL, USA
| | | | | | - Devin E Eckhoff
- Department of Surgery, University of Alabama at Birmingham, AL, USA; Department of Microbiology and Animal Resources Program, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David K C Cooper
- Department of Surgery, University of Alabama at Birmingham, AL, USA
| | - Hidetaka Hara
- Department of Surgery, University of Alabama at Birmingham, AL, USA.
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Singh AK, Goerlich CE, Shah AM, Zhang T, Tatarov I, Ayares D, Horvath KA, Mohiuddin MM. Cardiac Xenotransplantation: Progress in Preclinical Models and Prospects for Clinical Translation. Transpl Int 2022; 35:10171. [PMID: 35401039 PMCID: PMC8985160 DOI: 10.3389/ti.2022.10171] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/11/2022] [Indexed: 12/02/2022]
Abstract
Survival of pig cardiac xenografts in a non-human primate (NHP) model has improved significantly over the last 4 years with the introduction of costimulation blockade based immunosuppression (IS) and genetically engineered (GE) pig donors. The longest survival of a cardiac xenograft in the heterotopic (HHTx) position was almost 3 years and only rejected when IS was stopped. Recent reports of cardiac xenograft survival in a life-sustaining orthotopic (OHTx) position for 6 months is a significant step forward. Despite these achievements, there are still several barriers to the clinical success of xenotransplantation (XTx). This includes the possible transmission of porcine pathogens with pig donors and continued xenograft growth after XTx. Both these concerns, and issues with additional incompatibilities, have been addressed recently with the genetic modification of pigs. This review discusses the spectrum of issues related to cardiac xenotransplantation, recent progress in preclinical models, and its feasibility for clinical translation.
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Affiliation(s)
- Avneesh K. Singh
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Corbin E. Goerlich
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Aakash M. Shah
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Tianshu Zhang
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Ivan Tatarov
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
| | | | - Keith A. Horvath
- National Heart, Lung, and Blood Institute, National Institute of Health, Bethesda, MD, United States
| | - Muhammad M. Mohiuddin
- Department of Surgery, School of Medicine, University of Maryland, Baltimore, MD, United States
- *Correspondence: Muhammad M. Mohiuddin,
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Cooper DKC. The 2021 IXA Keith Reemtsma Lecture: Moving xenotransplantation to the clinic. Xenotransplantation 2022; 29:e12723. [PMID: 34967057 PMCID: PMC8995333 DOI: 10.1111/xen.12723] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/05/2021] [Indexed: 01/03/2023]
Abstract
Keith Reemtsma was a pioneer in xenotransplantation, the Honorary Founding President of the International Xenotransplantation Association (in 1998), and a wonderful personality. It is a privilege to be invited to give this lecture in his memory. If he were alive today, he would be delighted to see the progress that has been made in pig organ transplantation into nonhuman primate recipients. This progress has largely resulted from two major advances: (i) the increasing availability of pigs with multiple genetic manipulations aimed at protecting the cells of the organ from the primate immune response and (ii) the introduction of novel immunosuppressive agents that block the CD40/CD154 costimulation pathway. There is strong evidence from numerous in vitro studies that the transplantation of a triple-knockout pig organ, particularly if expressing several human protective proteins, into a patient is likely to be significantly more successful than if that same organ is transplanted into a nonhuman primate recipient. With this fact in mind, and in view of the advances currently being made, the time has surely come when we need to consider moving from the laboratory to the clinic. However, there are still questions we need to definitively resolve: (i) What exact genetic modifications do we need in the organ-source pig? (ii) What exact immunosuppressive regimen will we choose? (iii) How will we monitor the immune response and diagnose and treat rejection? and (iv) How do we plan to prevent or treat potential infectious complications? Furthermore, when these matters have been resolved, which patients will be offered a pig organ in the first trial? We have suggested that patients who are very unlikely to survive until a suitable deceased human donor kidney becomes available are those who should be considered for the initial trials. Assessing public attitudes to xenotransplantation is also important before embarking on a clinical trial. I suggest that progress is much more likely to be made from a small clinical trial than if we persist in carrying out experiments in an animal model that no longer mimics the clinical situation.
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Affiliation(s)
- David K C Cooper
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
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30
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Cooper DKC. Recent progress in the pig-to-nonhuman primate kidney transplantation model: Report of a symposium. Xenotransplantation 2022; 29:e12728. [PMID: 35001421 DOI: 10.1111/xen.12728] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 12/21/2021] [Indexed: 11/29/2022]
Abstract
Three excellent presentations at an industry-sponsored symposium at the (virtual) congress of the combined IXA/CTRMS (September 23-25, 2021) were directed to the value and limitations of the pig-to-nonhuman primate (NHP) kidney transplantation model. Daniel Firl and James Markmann provided a meta-analysis comparing the results of kidney allotransplantation and xenotransplantation in NHPs during the past 25 years. Remarkably, the authors had identified 73 published reports that included 910 individual experiments. Although recipient survival after allotransplantation was longer, the superiority over the survival of xenografts was less than anticipated. Given the excellent short- and medium-term results of clinical kidney allotransplantation today, these data provide hope that the results of clinical pig kidney xenotransplantation may prove significantly better than in NHPs. The authors identified several factors that were shown to statistically influence the success or failure of xenotransplantation. Jean Kwun provided valuable information relating to the longstanding question of whether the survival of a pig organ would be jeopardized if transplanted into an allosensitized recipient. He demonstrated that pig kidney transplantation in an HLA-sensitized patient may be at a disadvantage, although multiple genetic engineering of the organ-source pig significantly delayed rejection. In the initial clinical trials, therefore, it would seem wise to exclude any patient with evidence of anti-HLA antibodies. Andrew Adams reported longer survival (>1 year) of Rhesus monkeys with life-supporting pig kidney grafts than has been achieved previously. Although not consistently achieved, these excellent results were obtained with an anti-CD154mAb-based regimen after CD4+ T cell and partial CD20+ B cell depletion. Factors that might have contributed to this success, including the phenotype of the pig, the species of the recipient, the recipient's anti-pig antibody level, and the immunosuppressive regimen, were discussed. Importantly, pig kidney function appeared to be normal in long-term surviving monkeys. Each study contributed to our goal of introducing xenotransplantation into the clinic.
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Affiliation(s)
- David K C Cooper
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital, Boston, Massachusetts, USA
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31
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Lamm V, Ekser B, Vagefi PA, Cooper DK. Bridging to Allotransplantation-Is Pig Liver Xenotransplantation the Best Option? Transplantation 2022; 106:26-36. [PMID: 33653996 PMCID: PMC10124768 DOI: 10.1097/tp.0000000000003722] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In the past 20 y, the number of patients in the United States who died while waiting for a human donor liver totaled >52 000. The median national wait time for patients with acute liver failure and the most urgent liver transplant listing was 7 d in 2018. The need for a clinical "bridge" to allotransplantation is clear. Current options for supporting patients with acute liver failure include artificial liver support devices, extracorporeal liver perfusion, and hepatocyte transplantation, all of which have shown mixed results with regard to survival benefit and are largely experimental. Progress in the transplantation of genetically engineered pig liver grafts in nonhuman primates has grown steadily, with survival of the pig graft extended to almost 1 mo in 2017. Further advances may justify consideration of a pig liver transplant as a clinical bridge to allotransplantation. We provide a brief history of pig liver xenotransplantation, summarize the most recent progress in pig-to-nonhuman primate liver transplantation models, and suggest criteria that may be considered for patient selection for a clinical trial of bridging by genetically engineered pig liver xenotransplantation to liver allotransplantation.
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Affiliation(s)
- Vladimir Lamm
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Burcin Ekser
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN
| | - Parsia A. Vagefi
- Division of Surgical Transplantation, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | - David K.C. Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
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32
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Cooper DKC. Invited commentary. Xenotransplantation 2022; 29:e12737. [PMID: 35165943 PMCID: PMC10154073 DOI: 10.1111/xen.12737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 01/23/2022] [Accepted: 01/23/2022] [Indexed: 11/29/2022]
Affiliation(s)
- David K C Cooper
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
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33
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Cooper DKC, Hara H. "You cannot stay in the laboratory forever"*: Taking pig kidney xenotransplantation from the laboratory to the clinic. EBioMedicine 2021; 71:103562. [PMID: 34517284 PMCID: PMC8441149 DOI: 10.1016/j.ebiom.2021.103562] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/02/2021] [Accepted: 08/16/2021] [Indexed: 11/18/2022] Open
Abstract
Progress in life-supporting kidney transplantation in the genetically-engineered pig-to-nonhuman primate model has been encouraging, with pig kidneys sometimes supporting life for > 1 year. What steps need to be taken by (i) the laboratory team, and (ii) the clinical team to prepare for the first clinical trial? The major topics include (i) what currently-available genetic modifications are optimal to reduce the possibility of graft rejection, (ii) what immunosuppressive therapeutic regimen is optimal, and (iii) what steps need to be taken to minimize the risk of transfer of an infectious microorganism with the graft. We suggest that patients who are unlikely to live long enough to receive a kidney from a deceased human donor would benefit from the opportunity of a period of dialysis-free support by a pig kidney, and the experience gained would enable xenotransplantation to progress much more rapidly than if we remain in the laboratory.
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Affiliation(s)
- David K C Cooper
- Xenotransplantation Program, Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, 752 Lyons-Harrison Research Building, 701 19th Street South, Birmingham, AL 35294, USA.
| | - Hidetaka Hara
- Xenotransplantation Program, Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, 752 Lyons-Harrison Research Building, 701 19th Street South, Birmingham, AL 35294, USA
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34
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Bikhet M, Iwase H, Yamamoto T, Jagdale A, Foote JB, Ezzelarab M, Anderson DJ, Locke JE, Eckhoff DE, Hara H, Cooper DKC. What Therapeutic Regimen Will Be Optimal for Initial Clinical Trials of Pig Organ Transplantation? Transplantation 2021; 105:1143-1155. [PMID: 33534529 DOI: 10.1097/tp.0000000000003622] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We discuss what therapeutic regimen might be acceptable/successful in the first clinical trial of genetically engineered pig kidney or heart transplantation. As regimens based on a calcineurin inhibitor or CTLA4-Ig have proved unsuccessful, the regimen we administer to baboons is based on induction therapy with antithymocyte globulin, an anti-CD20 mAb (Rituximab), and cobra venom factor, with maintenance therapy based on blockade of the CD40/CD154 costimulation pathway (with an anti-CD40 mAb), with rapamycin, and a corticosteroid. An anti-inflammatory agent (etanercept) is administered for the first 2 wk, and adjuvant therapy includes prophylaxis against thrombotic complications, anemia, cytomegalovirus, and pneumocystis. Using this regimen, although antibody-mediated rejection certainly can occur, we have documented no definite evidence of an adaptive immune response to the pig xenograft. This regimen could also form the basis for the first clinical trial, except that cobra venom factor will be replaced by a clinically approved agent, for example, a C1-esterase inhibitor. However, none of the agents that block the CD40/CD154 pathway are yet approved for clinical use, and so this hurdle remains to be overcome. The role of anti-inflammatory agents remains unproven. The major difference between this suggested regimen and those used in allotransplantation is the replacement of a calcineurin inhibitor with a costimulation blockade agent, but this does not appear to increase the complications of the regimen.
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Affiliation(s)
- Mohamed Bikhet
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Hayato Iwase
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Takayuki Yamamoto
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Abhijit Jagdale
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Jeremy B Foote
- Department of Microbiology and Animal Resources Program, University of Alabama at Birmingham, Birmingham, AL
| | - Mohamed Ezzelarab
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Douglas J Anderson
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Jayme E Locke
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Devin E Eckhoff
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
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Abstract
Advances in genetic engineering, particularly CRISPR/Cas9, have resulted in the development of a triple glycan-knockout (TKO) pig. There is minimal human antipig antibody binding to TKO pig cells. The TKO background has decreased antibody binding to a sufficiently low level that any additional xenoantigens expressed on the cells can now be more easily detected. One of these xenoantigens is the swine major histocompatibility complex, termed swine leukocyte antigens (SLA). SLA are the homolog to HLAs, a protein complex expressed on human tissue capable of stimulating the development of new antibodies in allotransplantation. These antibodies can result in graft failure through hyperacute, acute, or chronic rejection. Our knowledge of SLA, particularly in the last 5 years, has grown considerably. The presence, cause, and methods to detect anti-SLA antibodies will need to be carefully considered for the first clinical trial of xenotransplantation. The focus of this review is to summarize the role of SLA in xenotransplantation and consider whether it will prove to be a major barrier. Techniques are now available to mutate target SLA amino acids to ensure that cross-reactive anti-HLA antibodies no longer bind to SLA on the cells of the organ-source pigs. While deletion of SLA expression is possible, it would render the pig at risk for infectious complications. The ideal organ-source pig for HLA highly sensitized recipients may therefore be 1 with site-specific mutations to eliminate cross-reactive binding.
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Affiliation(s)
- Joseph M Ladowski
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
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36
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Rao JS, Burlak C. Xenotransplantation literature update for September - October 2020. Xenotransplantation 2020; 28:e12665. [PMID: 33314409 DOI: 10.1111/xen.12665] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 11/20/2020] [Indexed: 12/27/2022]
Affiliation(s)
- Joseph Sushil Rao
- Department of Surgery, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN, USA.,Solid Organ Transplantation, Department of Surgery, University of Minnesota, Minneapolis, MN, USA
| | - Christopher Burlak
- Department of Surgery, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN, USA
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37
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Cooper DKC, Hara H, Iwase H, Yamamoto T, Wang ZY, Jagdale A, Bikhet MH, Nguyen HQ, Foote JB, Paris WD, Ayares D, Kumar V, Anderson DJ, Locke JE, Eckhoff DE. Pig kidney xenotransplantation: Progress toward clinical trials. Clin Transplant 2020; 35:e14139. [PMID: 33131148 DOI: 10.1111/ctr.14139] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/09/2020] [Accepted: 10/24/2020] [Indexed: 12/16/2022]
Abstract
Pig organ xenotransplantation offers a solution to the shortage of deceased human organs for transplantation. The pathobiological response to a pig xenograft is complex, involving antibody, complement, coagulation, inflammatory, and cellular responses. To overcome these barriers, genetic manipulation of the organ-source pigs has largely been directed to two major aims-(a) deletion of expression of the known carbohydrate xenoantigens against which humans have natural (preformed) antibodies, and (b) transgenic expression of human protective proteins, for example, complement- and coagulation-regulatory proteins. Conventional (FDA-approved) immunosuppressive therapy is unsuccessful in preventing an adaptive immune response to pig cells, but blockade of the CD40:CD154 costimulation pathway is successful. Survival of genetically engineered pig kidneys in immunosuppressed nonhuman primates can now be measured in months. Non-immunological aspects, for example, pig renal function, a hypovolemia syndrome, and rapid growth of the pig kidney after transplantation, are briefly discussed. We suggest that patients on the wait-list for a deceased human kidney graft who are unlikely to receive one due to long waiting times are those for whom kidney xenotransplantation might first be considered. The potential risk of infection, public attitudes to xenotransplantation, and ethical, regulatory, and financial aspects are briefly addressed.
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Affiliation(s)
- David K C Cooper
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hidetaka Hara
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hayato Iwase
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Takayuki Yamamoto
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Zheng-Yu Wang
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Abhijit Jagdale
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mohamed H Bikhet
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Huy Q Nguyen
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jeremy B Foote
- Department of Microbiology and Animal Resources Program, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Wayne D Paris
- Department of Social Work, Abilene Christian University, Abilene, TX, USA
| | | | - Vineeta Kumar
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Douglas J Anderson
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jayme E Locke
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Devin E Eckhoff
- Division of Transplantation, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
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38
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The resurgent landscape of xenotransplantation of pig organs in nonhuman primates. SCIENCE CHINA-LIFE SCIENCES 2020; 64:697-708. [PMID: 32975720 DOI: 10.1007/s11427-019-1806-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 08/27/2020] [Indexed: 12/14/2022]
Abstract
Organ shortage is a major bottleneck in allotransplantation and causes many wait-listed patients to die or become too sick for transplantation. Genetically engineered pigs have been discussed as a potential alternative to allogeneic donor organs. Although xenotransplantation of pig-derived organs in nonhuman primates (NHPs) has shown sequential advances in recent years, there are still underlying problems that need to be completely addressed before clinical applications, including (i) acute humoral xenograft rejection; (ii) acute cellular rejection; (iii) dysregulation of coagulation and inflammation; (iv) physiological incompatibility; and (v) cross-species infection. Moreover, various genetic modifications to the pig donor need to be fully characterized, with the aim of identifying the ideal transgene combination for upcoming clinical trials. In addition, suitable pretransplant screening methods need to be confirmed for optimal donor-recipient matching, ensuring a good outcome from xenotransplantation. Herein, we summarize the understanding of organ xenotransplantation in pigs-to-NHPs and highlight the current status and recent progress in extending the survival time of pig xenografts and recipients. We also discuss practical strategies for overcoming the obstacles to xenotransplantation mentioned above to further advance transplantation of pig organs in the clinic.
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39
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Yamamoto T, Hara H, Iwase H, Jagdale A, Bikhet MH, Morsi M, Cui Y, Nguyen HQ, Wang Z, Anderson DJ, Foote J, Schuurman H, Ayares D, Eckhoff DE, Cooper DKC. The final obstacle to successful pre‐clinical xenotransplantation? Xenotransplantation 2020; 27:e12596. [DOI: 10.1111/xen.12596] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/27/2020] [Accepted: 04/07/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Takayuki Yamamoto
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Hidetaka Hara
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Hayato Iwase
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Abhijit Jagdale
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Mohamed H. Bikhet
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Mahmoud.A. Morsi
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Yehua Cui
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Huy Q. Nguyen
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Zheng‐Yu Wang
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Douglas J. Anderson
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - Jeremy Foote
- Department of Microbiology and Animal Resources Program University of Alabama at Birmingham Birmingham AL USA
| | | | | | - Devin E. Eckhoff
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
| | - David K. C. Cooper
- Xenotransplantation Program Department of Surgery University of Alabama at Birmingham Birmingham AL USA
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Lu T, Yang B, Wang R, Qin C. Xenotransplantation: Current Status in Preclinical Research. Front Immunol 2020; 10:3060. [PMID: 32038617 PMCID: PMC6989439 DOI: 10.3389/fimmu.2019.03060] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/16/2019] [Indexed: 12/13/2022] Open
Abstract
The increasing life expectancy of humans has led to a growing numbers of patients with chronic diseases and end-stage organ failure. Transplantation is an effective approach for the treatment of end-stage organ failure; however, the imbalance between organ supply and the demand for human organs is a bottleneck for clinical transplantation. Therefore, xenotransplantation might be a promising alternative approach to bridge the gap between the supply and demand of organs, tissues, and cells; however, immunological barriers are limiting factors in clinical xenotransplantation. Thanks to advances in gene-editing tools and immunosuppressive therapy as well as the prolonged xenograft survival time in pig-to-non-human primate models, clinical xenotransplantation has become more viable. In this review, we focus on the evolution and current status of xenotransplantation research, including our current understanding of the immunological mechanisms involved in xenograft rejection, genetically modified pigs used for xenotransplantation, and progress that has been made in developing pig-to-pig-to-non-human primate models. Three main types of rejection can occur after xenotransplantation, which we discuss in detail: (1) hyperacute xenograft rejection, (2) acute humoral xenograft rejection, and (3) acute cellular rejection. Furthermore, in studies on immunological rejection, genetically modified pigs have been generated to bridge cross-species molecular incompatibilities; in the last decade, most advances made in the field of xenotransplantation have resulted from the production of genetically engineered pigs; accordingly, we summarize the genetically modified pigs that are currently available for xenotransplantation. Next, we summarize the longest survival time of solid organs in preclinical models in recent years, including heart, liver, kidney, and lung xenotransplantation. Overall, we conclude that recent achievements and the accumulation of experience in xenotransplantation mean that the first-in-human clinical trial could be possible in the near future. Furthermore, we hope that xenotransplantation and various approaches will be able to collectively solve the problem of human organ shortage.
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Affiliation(s)
- Tianyu Lu
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China.,NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing, China
| | - Bochao Yang
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China.,NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing, China
| | - Ruolin Wang
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China.,NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing, China
| | - Chuan Qin
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China.,NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing, China
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Abstract
There is a well-known worldwide shortage of deceased human donor organs for clinical transplantation. The transplantation of organs from genetically engineered pigs may prove an alternative solution. In the past 5 years, there have been sequential advances that have significantly increased pig graft survival in nonhuman primates. This progress has been associated with (1) the availability of increasingly sophisticated genetically engineered pigs; (2) the introduction of novel immunosuppressive agents, particularly those that block the second T-cell signal (costimulation blockade); (3) a better understanding of the inflammatory response to pig xenografts; and (4) increasing experience in the management of nonhuman primates with pig organ or cell grafts. The range of investigations required in experimental studies has increased. The standard immunologic assays are still carried out, but increasingly investigations aimed toward other pathobiologic barriers (e.g., coagulation dysregulation and inflammation) have become more important in determining injury to the graft.Now that prolonged graft survival, extending to months or even years, is increasingly being obtained, the function of the grafts can be more reliably assessed. If the source pigs are bred and housed under biosecure isolation conditions, and weaned early from the sow, most microorganisms can be eradicated from the herd. The potential risk of porcine endogenous retrovirus (PERV) infection remains unknown, but is probably small. Attention is being directed toward the selection of patients for the first clinical trials of xenotransplantation.
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Affiliation(s)
- David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA.
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Cooper DKC, Hara H, Iwase H, Yamamoto T, Jagdale A, Kumar V, Mannon RB, Hanaway MJ, Anderson DJ, Eckhoff DE. Clinical Pig Kidney Xenotransplantation: How Close Are We? J Am Soc Nephrol 2019; 31:12-21. [PMID: 31792154 DOI: 10.1681/asn.2019070651] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Patients with ESKD who would benefit from a kidney transplant face a critical and continuing shortage of kidneys from deceased human donors. As a result, such patients wait a median of 3.9 years to receive a donor kidney, by which time approximately 35% of transplant candidates have died while waiting or have been removed from the waiting list. Those of blood group B or O may experience a significantly longer waiting period. This problem could be resolved if kidneys from genetically engineered pigs offered an alternative with an acceptable clinical outcome. Attempts to accomplish this have followed two major paths: deletion of pig xenoantigens, as well as insertion of "protective" human transgenes to counter the human immune response. Pigs with up to nine genetic manipulations are now available. In nonhuman primates, administering novel agents that block the CD40/CD154 costimulation pathway, such as an anti-CD40 mAb, suppresses the adaptive immune response, leading to pig kidney graft survival of many months without features of rejection (experiments were terminated for infectious complications). In the absence of innate and adaptive immune responses, the transplanted pig kidneys have generally displayed excellent function. A clinical trial is anticipated within 2 years. We suggest that it would be ethical to offer a pig kidney transplant to selected patients who have a life expectancy shorter than the time it would take for them to obtain a kidney from a deceased human donor. In the future, the pigs will also be genetically engineered to control the adaptive immune response, thus enabling exogenous immunosuppressive therapy to be significantly reduced or eliminated.
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Affiliation(s)
| | - Hidetaka Hara
- Division of Transplantation, Department of Surgery and
| | - Hayato Iwase
- Division of Transplantation, Department of Surgery and
| | | | | | - Vineeta Kumar
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Roslyn Bernstein Mannon
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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Yamamoto T, Hara H, Foote J, Wang L, Li Q, Klein EC, Schuurman HJ, Zhou H, Li J, Tector AJ, Zhang Z, Ezzelarab M, Lovingood R, Ayares D, Eckhoff DE, Cooper DKC, Iwase H. Life-supporting Kidney Xenotransplantation From Genetically Engineered Pigs in Baboons: A Comparison of Two Immunosuppressive Regimens. Transplantation 2019; 103:2090-2104. [PMID: 31283686 DOI: 10.1097/tp.0000000000002796] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND The aims of this study were to evaluate the efficacy of US Food and Drug Administration-approved drugs in genetically engineered pig-to-baboon kidney xenotransplantation and compare the results with those using an anti-CD40 monoclonal antibody (mAb)-based regimen. METHODS Ten life-supporting kidney transplants were carried out in baboons using α1,3-galactosyltransferase gene-knockout/CD46 pigs with various other genetic manipulations aimed at controlling coagulation dysregulation. Eight transplants resulted in informative data. Immunosuppressive therapy consisted of induction with antithymocyte globulin and anti-CD20mAb, and maintenance based on either (1) CTLA4-Ig and/or tacrolimus (+rapamycin or mycophenolate mofetil) (GroupA [US Food and Drug Administration-approved regimens], n = 4) or (2) anti-CD40mAb + rapamycin (GroupB, n = 4). All baboons received corticosteroids, interleukin-6R blockade, and tumor necrosis factor-α blockade. Baboons were followed by clinical and laboratory monitoring of kidney function, coagulation, and immune parameters. At euthanasia, morphological and immunohistochemical studies were performed on the kidney grafts. RESULTS The median survival in GroupB was 186 days (range 90-260), which was significantly longer than in GroupA; median 14 days (range 12-32) (P < 0.01). Only GroupA baboons developed consumptive coagulopathy and the histopathological features of thrombotic microangiopathic glomerulopathy and interstitial arterial vasculitis. CONCLUSIONS Recognizing that the pig donors in each group differed in some genetic modifications, these data indicate that maintenance immunosuppression including anti-CD40mAb may be important to prevent pig kidney graft failure.
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Affiliation(s)
- Takayuki Yamamoto
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Jeremy Foote
- Department of Microbiology and Animal Resources Program, University of Alabama at Birmingham, Birmingham, AL
| | - Liaoran Wang
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
- Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - Qi Li
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
- Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - Edwin C Klein
- Division of Laboratory Animal Resources, University of Pittsburgh, Pittsburgh, PA
| | | | - Hongmin Zhou
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
- Department of Cardiothoracic Surgery, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Juan Li
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
- Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - A Joseph Tector
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Zhongqiang Zhang
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA
- Department of General Surgery and Organ Transplantation, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Mohamed Ezzelarab
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA
| | - Ray Lovingood
- Kirklin Clinic Pharmacy, University of Alabama at Birmingham, Birmingham, AL
| | | | - Devin E Eckhoff
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
| | - Hayato Iwase
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
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Xenotransplantation tolerance: applications for recent advances in modified swine. Curr Opin Organ Transplant 2019; 23:642-648. [PMID: 30379724 DOI: 10.1097/mot.0000000000000585] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW The aim of this study was to review the recent progress in xenotransplantation achieved through genetic engineering and discuss the potential of tolerance induction to overcome remaining barriers to extended xenograft survival. RECENT FINDINGS The success of life-saving allotransplantation has created a demand for organ transplantation that cannot be met by the supply of human organs. Xenotransplantation is one possible solution that would allow for a nearly unlimited supply of organs. Recent genetic engineering of swine has decreased the reactivity of preformed antibodies to some, but not all, potential human recipients. Experiments using genetically modified swine organs have now resulted in survival of life-supporting kidneys for over a year. However, the grafts show evidence of antibody-mediated rejection on histology, suggesting additional measures will be required for further extension of graft survival. Tolerance induction through mixed chimerism or thymic transplantation across xenogeneic barriers would be well suited for patients with a positive crossmatch to genetically modified swine or relatively negative crossmatches to genetically modified swine, respectively. SUMMARY This review highlights the current understanding of the immunologic processes in xenotransplantation and describes the development and application of strategies designed to overcome them from the genetic modification of the source animal to the induction of tolerance to xenografts.
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45
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Zhang X, Li X, Yang Z, Tao K, Wang Q, Dai B, Qu S, Peng W, Zhang H, Cooper DKC, Dou K. A review of pig liver xenotransplantation: Current problems and recent progress. Xenotransplantation 2019; 26:e12497. [PMID: 30767272 DOI: 10.1111/xen.12497] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/01/2019] [Accepted: 01/07/2019] [Indexed: 12/14/2022]
Abstract
Pig liver xenotransplantation appears to be more perplexing when compared to heart or kidney xenotransplantation, even though great progress has been achieved. The relevant molecular mechanisms involved in xenogeneic rejection, including coagulopathy, and particularly thrombocytopenia, are complex, and need to be systematically investigated. The deletion of expression of Gal antigens in the liver graft highlights the injurious impact of nonGal antigens, which continue to induce humoral rejection. Innate immunity, particularly mediated by macrophages and natural killer cells, interplays with inflammation and coagulation disorders. Kupffer cells and liver sinusoidal endothelial cells (LSECs) together mediate leukocyte, erythrocyte, and platelet sequestration and phagocytosis, which can be exacerbated by increased cytokine production, cell desialylation, and interspecies incompatibilities. The coagulation cascade is activated by release of tissue factor which can be dependent or independent of the xenoreactive immune response. Depletion of endothelial anticoagulants and anti-platelet capacity amplify coagulation activation, and interspecies incompatibilities of coagulation-regulatory proteins facilitate dysregulation. LSECs involved in platelet phagocytosis and transcytosis, coupled with hepatocyte-mediated degradation, are responsible for thrombocytopenia. Adaptive immunity could also be problematic in long-term liver graft survival. Currently, relevant evidence and study results of various genetic modifications to the pig donor need to be fully determined, with the aim of identifying the ideal transgene combination for pig liver xenotransplantation. We believe that clinical trials of pig liver xenotransplantation should initially be considered as a bridge to allotransplantation.
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Affiliation(s)
- Xuan Zhang
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Xiao Li
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Zhaoxu Yang
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Kaishan Tao
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Quancheng Wang
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Bin Dai
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Shibin Qu
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Wei Peng
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Hong Zhang
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kefeng Dou
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
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46
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Smood B, Hara H, Schoel LJ, Cooper DKC. Genetically-engineered pigs as sources for clinical red blood cell transfusion: What pathobiological barriers need to be overcome? Blood Rev 2019; 35:7-17. [PMID: 30711308 DOI: 10.1016/j.blre.2019.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 01/02/2019] [Accepted: 01/25/2019] [Indexed: 12/27/2022]
Abstract
An alternative to human red blood cells (RBCs) for clinical transfusion would be advantageous, particularly in situations of massive acute blood loss (where availability and compatibility are limited) or chronic hematologic diseases requiring frequent transfusions (resulting in alloimmunization). Ideally, any alternative must be neither immunogenic nor pathogenic, but readily available, inexpensive, and physiologically effective. Pig RBCs (pRBCs) provide a promising alternative due to their several similarities with human RBCs, and our increasing ability to genetically-modify pigs to reduce cellular immunogenicity. We briefly summarize the history of xenotransfusion, the progress that has been made in recent years, and the remaining barriers. These barriers include prevention of (i) human natural antibody binding to pRBCs, (ii) their phagocytosis by macrophages, and (iii) the T cell adaptive immune response (in the absence of exogenous immunosuppressive therapy). Although techniques of genetic engineering have advanced in recent years, novel methods to introduce human transgenes into pRBCs (which do not have nuclei) will need to be developed before clinical trials can be initiated.
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Affiliation(s)
- Benjamin Smood
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Leah J Schoel
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA.
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Cooper DK, Ezzelarab M, Iwase H, Hara H. Perspectives on the Optimal Genetically Engineered Pig in 2018 for Initial Clinical Trials of Kidney or Heart Xenotransplantation. Transplantation 2018; 102:1974-1982. [PMID: 30247446 PMCID: PMC6249080 DOI: 10.1097/tp.0000000000002443] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
For a clinical trial today, what might realistically be the optimal pig among those currently available? Deletion of expression of the 3 pig carbohydrate antigens, against which humans have natural (preformed) antibodies (triple-knockout pigs), should form the basis of any clinical trial. However, because both complement and coagulation can be activated in the absence of antibody, the expression of human complement- and coagulation-regulatory proteins is likely to be important in protecting the graft further. Any genetic manipulation that might reduce inflammation of the graft, for example, expression of hemeoxygenase-1 or A20, may also be beneficial to the long-term survival of the graft. The transgene for human CD47 is likely to have a suppressive effect on monocyte/macrophage and T-cell activity. Furthermore, deletion of xenoantigen expression and expression of a human complement-regulatory protein are both associated with a reduced T-cell response. Although there are several other genetic manipulations that may reduce the T-cell response further, it seems likely that exogenous immunosuppressive therapy, particularly if it includes costimulation blockade, will be sufficient. We would therefore suggest that, with our present knowledge and capabilities, the optimal pig might be a triple-knockout pig that expressed 1 or more human complement-regulatory proteins, 1 or more human coagulation-regulatory proteins, a human anti-inflammatory transgene, and CD47. Absent or minimal antibody binding is important, but we suggest that the additional insertion of protective human transgenes will be beneficial, and may be essential.
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Affiliation(s)
- David K.C. Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mohamed Ezzelarab
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hayato Iwase
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
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48
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Yamamoto T, Li Q, Hara H, Wang L, Zhou H, Li J, Eckhoff DE, Joseph Tector A, Klein EC, Lovingood R, Ezzelarab M, Ayares D, Wang Y, Cooper DKC, Iwase H. B cell phenotypes in baboons with pig artery patch grafts receiving conventional immunosuppressive therapy. Transpl Immunol 2018; 51:12-20. [PMID: 30092338 PMCID: PMC6249078 DOI: 10.1016/j.trim.2018.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/03/2018] [Accepted: 08/03/2018] [Indexed: 12/29/2022]
Abstract
BACKGROUND In the pig-to-baboon artery patch model with no immunosuppressive therapy, a graft from an α1,3-galactosyltransferase gene-knockout (GTKO) pig elicits a significant anti-nonGal IgG response, indicating sensitization to the graft. A costimulation blockade-based regimen, e.g., anti-CD154mAb or anti-CD40mAb, prevents sensitization. However, neither of these agents is currently FDA-approved. The aim of the present study was to determine the efficacy of FDA-approved agents on the T and B cell responses. METHODS Artery patch xenotransplantation in baboons was carried out using GTKO/CD46 pigs with (n = 2) or without (n = 1) the mutant transgene for CIITA-knockdown. Immunosuppressive therapy consisted of induction with ATG and anti-CD20mAb, and maintenance with different combinations of CTLA4-Ig, tacrolimus, and rapamycin. In addition, all 3 baboons received daily corticosteroids, the IL-6R blocker, tocilizumab, at regular intervals, and the TNF-α blocker, etanercept, for the first 2 weeks. Recipient blood was monitored for anti-nonGal antibody levels by flow cytometry (using GTKO/CD46 pig aortic endothelial cells), and mixed lymphocyte reaction (MLR). CD22+B cell profiles (naïve [IgD+/CD27-], non-switched memory [IgD+/CD27+], and switched memory [IgD-/CD27+] B cell subsets) were measured by flow cytometry. At 6 months, the baboons were euthanized and the grafts were examined histologically. RESULTS No elicited anti-pig antibodies developed in any baboon. The frequency of naïve memory B cells increased significantly (from 34% to 90%, p = 0.0015), but there was a significant decrease in switched memory B cells (from 17% to 0.5%, p = 0.015). MLR showed no increase in the proliferative T cell response in those baboons that had received CTLA4-Ig (n = 2). Histological examination showed few or no features of rejection in any graft. CONCLUSIONS The data suggest that immunosuppressive therapy with only FDA-approved agents may be adequate to prevent an adaptive immune response to a genetically-engineered pig graft, particularly if CTLA4-Ig is included in the regimen, in part because the development of donor-specific memory B cells is inhibited.
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Affiliation(s)
- Takayuki Yamamoto
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Qi Li
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA; Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Liaoran Wang
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA; Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - Hongmin Zhou
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Cardiothoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Juan Li
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA; Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - Devin E Eckhoff
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - A Joseph Tector
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Edwin C Klein
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ray Lovingood
- Kirklin Clinic Pharmacy, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mohamed Ezzelarab
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Yi Wang
- Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hayato Iwase
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA.
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49
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Sykes M. IXA Honorary Member Lecture, 2017: The long and winding road to tolerance. Xenotransplantation 2018; 25:e12419. [PMID: 29913040 DOI: 10.1111/xen.12419] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/03/2018] [Indexed: 12/18/2022]
Abstract
The last 15 years or so have seen exciting progress in xenotransplantation, with porcine organ grafts surviving months or even years in non-human primates. These advances reflect the application of new scientific knowledge, improved immunosuppressive agents, and genetic engineering. The field has recently enjoyed a renaissance of interest and hope, largely due to the exponential increase in our capacity to genetically engineer porcine source animals. However, immune responses to xenografts are very powerful and widespread clinical application of xenotransplantation will depend on the ability to suppress these immune responses while preserving the capacity to protect both the recipient and the graft from infectious microorganisms. Our work over the last three decades has aimed to engineer the immune system of the recipient in a manner that achieves specific tolerance to the xenogeneic donor while preserving otherwise normal immune function. Important proofs of principle have been obtained, first in rodents, and later in human immune systems in "humanized mice" and finally in non-human primates, demonstrating the capacity and potential synergy of mixed xenogeneic chimerism and xenogeneic thymic transplantation in tolerizing multiple arms of the immune system. Considering the fact that clinical tolerance has recently been achieved for allografts and the even greater importance of avoiding excessive immunosuppression for xenografts, it is my belief that it is both possible and imperative that we likewise achieve xenograft tolerance. I expect this to be accomplished through the availability of targeted approaches to recipient immune conditioning, understanding of immunological mechanisms of tolerance, advanced knowledge of physiological incompatibilities, and the availability of inbred miniature swine with optimized use of genetic engineering.
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Affiliation(s)
- Megan Sykes
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA.,Department of Medicine, Columbia University, New York, NY, USA.,Department of Microbiology & Immunology, Columbia University, New York, NY, USA.,Department of Surgery, Columbia University, New York, NY, USA
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50
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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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