1
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Burdorf L, Gao Z, Riner A, Sievert E, Harris DG, Kuravi KV, Morrill BH, Habibabady Z, Rybak E, Dahi S, Zhang T, Schwartz E, Kang E, Cheng X, Esmon CT, Phelps CJ, Ayares DL, Pierson RN, Azimzadeh AM. Expression of human thrombomodulin by GalTKO.hCD46 pigs modulates coagulation cascade activation by endothelial cells and during ex vivo lung perfusion with human blood. Xenotransplantation 2023; 30:e12828. [PMID: 37767640 PMCID: PMC10840969 DOI: 10.1111/xen.12828] [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: 12/08/2020] [Revised: 08/21/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023]
Abstract
Thrombomodulin is important for the production of activated protein C (APC), a molecule with significant regulatory roles in coagulation and inflammation. To address known molecular incompatibilities between pig thrombomodulin and human thrombin that affect the conversion of protein C into APC, GalTKO.hCD46 pigs have been genetically modified to express human thrombomodulin (hTBM). The aim of this study was to evaluate the impact of transgenic hTBM expression on the coagulation dysregulation that is observed in association with lung xenograft injury in an established lung perfusion model, with and without additional blockade of nonphysiologic interactions between pig vWF and human GPIb axis. Expression of hTBM was variable between pigs at the transcriptional and protein level. hTBM increased the activation of human protein C and inhibited thrombosis in an in vitro flow perfusion assay, confirming that the expressed protein was functional. Decreased platelet activation was observed during ex vivo perfusion of GalTKO.hCD46 lungs expressing hTBM and, in conjunction with transgenic hTBM, blockade of the platelet GPIb receptor further inhibited platelets and increased survival time. Altogether, our data indicate that expression of transgenic hTBM partially addresses coagulation pathway dysregulation associated with pig lung xenograft injury and, in combination with vWF-GP1b-directed strategies, is a promising approach to improve the outcomes of lung xenotransplantation.
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Affiliation(s)
- Lars Burdorf
- Center for Transplantation Sciences, Department of Surgery,
Massachusetts General Hospital, Boston, MA, USA
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Zhuo Gao
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing
Medical University, Nanjing, China, USA
| | - Andrea Riner
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Evelyn Sievert
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Donald G. Harris
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | | | | | - Zahra Habibabady
- Center for Transplantation Sciences, Department of Surgery,
Massachusetts General Hospital, Boston, MA, USA
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Elana Rybak
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Siamak Dahi
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Tianshu Zhang
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Evan Schwartz
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Elizabeth Kang
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Xiangfei Cheng
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Charles T. Esmon
- Cardiovascular Biology Research Program, Oklahoma Medical
Research Foundation, Department of Pathology, University of Oklahoma Health Sciences
Center, Oklahoma City, OK, USA
| | | | | | - Richard N. Pierson
- Center for Transplantation Sciences, Department of Surgery,
Massachusetts General Hospital, Boston, MA, USA
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
| | - Agnes M. Azimzadeh
- Center for Transplantation Sciences, Department of Surgery,
Massachusetts General Hospital, Boston, MA, USA
- Department of Surgery, University of Maryland School of
Medicine, and VA Maryland Health Care System, Baltimore, MD, USA
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2
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Chaban R, McGrath G, Habibabady Z, Rosales I, Burdorf L, Ayares DL, Rybak E, Zhang T, Harris DG, Dahi S, Ali F, Parsell DM, Braileanu G, Cheng X, Sievert E, Phelps C, Azimzadeh AM, Pierson RN. Increased human complement pathway regulatory protein gene dose is associated with increased endothelial expression and prolonged survival during ex-vivo perfusion of GTKO pig lungs with human blood. Xenotransplantation 2023; 30:e12812. [PMID: 37504492 DOI: 10.1111/xen.12812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/29/2023] [Accepted: 07/13/2023] [Indexed: 07/29/2023]
Abstract
INTRODUCTION Expression of human complement pathway regulatory proteins (hCPRP's) such as CD46 or CD55 has been associated with improved survival of pig organ xenografts in multiple different models. Here we evaluate the hypothesis that an increased human CD46 gene dose, through homozygosity or additional expression of a second hCPRP, is associated with increased protein expression and with improved protection from injury when GTKO lung xenografts are perfused with human blood. METHODS Twenty three GTKO lungs heterozygous for human CD46 (GTKO.heteroCD46), 10 lungs homozygous for hCD46 (GTKO.homoCD46), and six GTKO.homoCD46 lungs also heterozygous for hCD55 (GTKO.homoCD46.hCD55) were perfused with human blood for up to 4 h in an ex vivo circuit. RESULTS Relative to GTKO.heteroCD46 (152 min, range 5-240; 6/23 surviving at 4 h), survival was significantly improved for GTKO.homoCD46 (>240 min, range 45-240, p = .034; 7/10 surviving at 4 h) or GTKO.homoCD46.hCD55 lungs (>240 min, p = .001; 6/6 surviving at 4 h). Homozygosity was associated with increased capillary expression of hCD46 (p < .0001). Increased hCD46 expression was associated with significantly prolonged lung survival (p = .048),) but surprisingly not with reduction in measured complement factor C3a. Hematocrit, monocyte count, and pulmonary vascular resistance were not significantly altered in association with increased hCD46 gene dose or protein expression. CONCLUSION Genetic engineering approaches designed to augment hCPRP activity - increasing the expression of hCD46 through homozygosity or co-expressing hCD55 with hCD46 - were associated with prolonged GTKO lung xenograft survival. Increased expression of hCD46 was associated with reduced coagulation cascade activation, but did not further reduce complement activation relative to lungs with relatively low CD46 expression. We conclude that coagulation pathway dysregulation contributes to injury in GTKO pig lung xenografts perfused with human blood, and that the survival advantage for lungs with increased hCPRP expression is likely attributable to improved endothelial thromboregulation.
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Affiliation(s)
- Ryan Chaban
- Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, Massachusetts, USA
- Department of Cardiac and Vascular Surgery, University Hospital of Johannes Gutenberg University Mainz, Mainz, Germany
| | - Gannon McGrath
- Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, Massachusetts, USA
| | - Zahra Habibabady
- Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, Massachusetts, USA
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ivy Rosales
- Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, Massachusetts, USA
| | - Lars Burdorf
- Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, Massachusetts, USA
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Revivicor, Inc., Blacksburg, Virginia, USA
| | | | - Elana Rybak
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Tianshu Zhang
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Donald G Harris
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Siamak Dahi
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Franchesca Ali
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Dawn M Parsell
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Gheorghe Braileanu
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Xiangfei Cheng
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Evelyn Sievert
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Agnes M Azimzadeh
- Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, Massachusetts, USA
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Richard N Pierson
- Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, Massachusetts, USA
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
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3
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Chan JCY, Chaban R, Chang SH, Angel LF, Montgomery RA, Pierson RN. Future of Lung Transplantation: Xenotransplantation and Bioengineering Lungs. Clin Chest Med 2023; 44:201-214. [PMID: 36774165 PMCID: PMC11078107 DOI: 10.1016/j.ccm.2022.11.003] [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] [Indexed: 02/11/2023]
Abstract
Xenotransplantation promises to alleviate the issue of donor organ shortages and to decrease waiting times for transplantation. Recent advances in genetic engineering have allowed for the creation of pigs with up to 16 genetic modifications. Several combinations of genetic modifications have been associated with extended graft survival and life-supporting function in experimental heart and kidney xenotransplants. Lung xenotransplantation carries specific challenges related to the large surface area of the lung vascular bed, its innate immune system's intrinsic hyperreactivity to perceived 'danger', and its anatomic vulnerability to airway flooding after even localized loss of alveolocapillary barrier function. This article discusses the current status of lung xenotransplantation, and challenges related to immunology, physiology, anatomy, and infection. Tissue engineering as a feasible alternative to develop a viable lung replacement solution is discussed.
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Affiliation(s)
- Justin C Y Chan
- NYU Transplant Institute, New York University, 530 1st Avenue, Suite 7R, New York, NY 10016, USA.
| | - Ryan Chaban
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA; Department of Cardiovascular Surgery, University Hospital of Johannes Gutenberg University, Langenbeckstr. 1, Bau 505, 5. OG55131 Mainz, Germany
| | - Stephanie H Chang
- NYU Transplant Institute, New York University, 530 1st Avenue, Suite 7R, New York, NY 10016, USA
| | - Luis F Angel
- NYU Transplant Institute, New York University, 530 1st Avenue, Suite 7R, New York, NY 10016, USA
| | - Robert A Montgomery
- NYU Transplant Institute, New York University, 530 1st Avenue, Suite 7R, New York, NY 10016, USA
| | - Richard N Pierson
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
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4
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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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5
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Miura S, Habibabady ZA, Pollok F, Connolly M, Pratts S, Dandro A, Sorrells L, Karavi K, Phelps C, Eyestone W, Ayares D, Burdorf L, Azimzadeh A, Pierson RN. Effects of human TFPI and CD47 expression and selectin and integrin inhibition during GalTKO.hCD46 pig lung perfusion with human blood. Xenotransplantation 2022; 29:e12725. [PMID: 35234315 PMCID: PMC10207735 DOI: 10.1111/xen.12725] [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] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/30/2021] [Accepted: 12/17/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND Loss of barrier function when GalTKO.hCD46 porcine lungs are perfused with human blood is associated with coagulation pathway dysregulation, innate immune system activation, and rapid sequestration of human formed blood elements. Here, we evaluate whether genetic expression of human tissue factor pathway inhibitor (hTFPI) and human CD47 (hCD47), alone or with combined selectin and integrin adhesion pathway inhibitors, delays GalTKO.hCD46 porcine lung injury or modulates neutrophil and platelet sequestration. METHODS In a well-established paired ex vivo lung perfusion model, GalTKO.hCD46.hTFPI.hCD47 transgenic porcine lungs (hTFPI.hCD47, n = 7) were compared to GalTKO.hCD46 lungs (reference, n = 5). All lung donor pigs were treated with a thromboxane synthase inhibitor, anti-histamine, and anti-GPIb integrin-blocking Fab, and were pre-treated with Desmopressin. In both genotypes, one lung of each pair was additionally treated with PSGL-1 and GMI-1271 (P- and E-selectin) and IB4 (CD11b/18 integrin) adhesion inhibitors (n = 6 hTFPI.hCD47, n = 3 reference). RESULTS All except for two reference lungs did not fail within 480 min when experiments were electively terminated. Selectin and integrin adhesion inhibitors moderately attenuated initial pulmonary vascular resistance (PVR) elevation in hTFPI.hCD47 lungs. Neutrophil sequestration was significantly delayed during the early time points following reperfusion and terminal platelet activation was attenuated in association with lungs expressing hTFPI.hCD47, but additional adhesion pathway inhibitors did not show further effects with either lung genotype. CONCLUSION Expression of hTFPI.hCD47 on porcine lung may be useful as part of an integrated strategy to prevent neutrophil adhesion and platelet activation that are associated with xenograft injury. Additionally, targeting canonical selectin and integrin adhesion pathways reduced PVR elevation associated with hTFPI.hCD47 expression, but did not significantly attenuate neutrophil or platelet sequestration. We conclude that other adhesive mechanisms mediate the residual sequestration of human formed blood elements to pig endothelium that occurs even in the context of the multiple genetic modifications and drug treatments tested here.
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Affiliation(s)
- Shuhei Miura
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Cardiovascular Surgery, Teine Keijinkai Hospital, Sapporo, Japan
| | - Zahra A. Habibabady
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Franziska Pollok
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Margaret Connolly
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Shannon Pratts
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | | | | | | | | | | | - Lars Burdorf
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Agnes Azimzadeh
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Richard N. Pierson
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA
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6
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Habibabady ZA, Sendil S, Ellett F, Pollok F, Elias GF, French BM, Sun W, Braileanu G, Burdorf L, Irimia D, Pierson RN, Azimzadeh AM. Human erythrocyte fragmentation during ex-vivo pig organ perfusion. Xenotransplantation 2022; 29:e12729. [PMID: 35112383 PMCID: PMC8995366 DOI: 10.1111/xen.12729] [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: 10/21/2021] [Revised: 12/22/2021] [Accepted: 01/10/2022] [Indexed: 01/25/2023]
Abstract
Platelet sequestration is a common process during organ reperfusion after transplantation. However, instead of lower platelet counts, when using traditional hemocytometers and light microscopy, we observed physiologically implausible platelet counts in the course of ex-vivo lung and liver xenograft organ perfusion studies. We employed conventional flow cytometry (FC) and imaging FC (AMINS ImageStream X) to investigate the findings and found platelet-sized fragments in the circulation that are mainly derived from red blood cell membranes. We speculate that this erythrocyte fragmentation contributes to anemia during in-vivo organ xenotransplant.
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Affiliation(s)
- Zahra A. Habibabady
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD,Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, MA
| | - Selin Sendil
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD
| | - Felix Ellett
- Center for Engineering in Medicine and Surgery, Massachusetts General Hospital, Harvard School of Medicine, and Shriners Burns Hospital, Boston, MA
| | - Franziska Pollok
- Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, MA,Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Gabriela F. Elias
- Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, MA
| | - Beth M. French
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD
| | - Wenji Sun
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD
| | - Gheorghe Braileanu
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD
| | - Lars Burdorf
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD,Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, MA
| | - Daniel Irimia
- Center for Engineering in Medicine and Surgery, Massachusetts General Hospital, Harvard School of Medicine, and Shriners Burns Hospital, Boston, MA
| | - Richard N. Pierson
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD,Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, MA
| | - Agnes M. Azimzadeh
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD,Center for Transplantation Sciences and Department of Surgery, Massachusetts General Hospital and Harvard School of Medicine, Boston, MA
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7
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Burdorf L, Laird CT, Harris DG, Connolly MR, Habibabady Z, Redding E, O’Neill NA, Cimeno A, Parsell D, Phelps C, Ayares D, Azimzadeh AM, Pierson RN. Pig-to-baboon lung xenotransplantation: Extended survival with targeted genetic modifications and pharmacologic treatments. Am J Transplant 2022; 22:28-45. [PMID: 34424601 PMCID: PMC10292947 DOI: 10.1111/ajt.16809] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 08/05/2021] [Accepted: 08/05/2021] [Indexed: 01/25/2023]
Abstract
Galactosyl transferase knock-out pig lungs fail rapidly in baboons. Based on previously identified lung xenograft injury mechanisms, additional expression of human complement and coagulation pathway regulatory proteins, anti-inflammatory enzymes and self-recognition receptors, and knock-down of the β4Gal xenoantigen were tested in various combinations. Transient life-supporting GalTKO.hCD46 lung function was consistently observed in association with either hEPCR (n = 15), hTBM (n = 4), or hEPCR.hTFPI (n = 11), but the loss of vascular barrier function in the xenograft and systemic inflammation in the recipient typically occurred within 24 h. Co-expression of hEPCR and hTBM (n = 11) and additionally blocking multiple pro-inflammatory innate and adaptive immune mechanisms was more consistently associated with survival >1 day, with one recipient surviving for 31 days. Combining targeted genetic modifications to the lung xenograft with selective innate and adaptive immune suppression enables prolonged initial life-supporting lung function and extends lung xenograft recipient survival, and illustrates residual barriers and candidate treatment strategies that may enable the clinical application of other organ xenografts.
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Affiliation(s)
- Lars Burdorf
- Division of Cardiac Surgery, Department of Surgery, and
Center for Transplantation Sciences, Massachusetts General Hospital, Boston,
Massachusetts, USA
- Department of Surgery, University of Maryland School of
Medicine, Baltimore, Maryland, USA
| | - Christopher T. Laird
- Department of Surgery, University of Maryland School of
Medicine, Baltimore, Maryland, USA
| | - Donald G. Harris
- Department of Surgery, University of Maryland School of
Medicine, Baltimore, Maryland, USA
| | - Margaret R. Connolly
- Division of Cardiac Surgery, Department of Surgery, and
Center for Transplantation Sciences, Massachusetts General Hospital, Boston,
Massachusetts, USA
| | - Zahra Habibabady
- Division of Cardiac Surgery, Department of Surgery, and
Center for Transplantation Sciences, Massachusetts General Hospital, Boston,
Massachusetts, USA
- Department of Surgery, University of Maryland School of
Medicine, Baltimore, Maryland, USA
| | - Emily Redding
- Division of Cardiac Surgery, Department of Surgery, and
Center for Transplantation Sciences, Massachusetts General Hospital, Boston,
Massachusetts, USA
| | - Natalie A. O’Neill
- Department of Surgery, University of Maryland School of
Medicine, Baltimore, Maryland, USA
| | - Arielle Cimeno
- Department of Surgery, University of Maryland School of
Medicine, Baltimore, Maryland, USA
| | - Dawn Parsell
- Department of Surgery, University of Maryland School of
Medicine, Baltimore, Maryland, USA
| | | | | | - Agnes M. Azimzadeh
- Division of Cardiac Surgery, Department of Surgery, and
Center for Transplantation Sciences, Massachusetts General Hospital, Boston,
Massachusetts, USA
- Department of Surgery, University of Maryland School of
Medicine, Baltimore, Maryland, USA
| | - Richard N. Pierson
- Division of Cardiac Surgery, Department of Surgery, and
Center for Transplantation Sciences, Massachusetts General Hospital, Boston,
Massachusetts, USA
- Department of Surgery, University of Maryland School of
Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Administration Medical Center,
Baltimore, Maryland, USA
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8
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Kano M, Mizutani E, Homma S, Masaki H, Nakauchi H. Xenotransplantation and interspecies organogenesis: current status and issues. Front Endocrinol (Lausanne) 2022; 13:963282. [PMID: 35992127 PMCID: PMC9388829 DOI: 10.3389/fendo.2022.963282] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/06/2022] [Indexed: 12/04/2022] Open
Abstract
Pancreas (and islet) transplantation is the only curative treatment for type 1 diabetes patients whose β-cell functions have been abolished. However, the lack of donor organs has been the major hurdle to save a large number of patients. Therefore, transplantation of animal organs is expected to be an alternative method to solve the serious shortage of donor organs. More recently, a method to generate organs from pluripotent stem cells inside the body of other species has been developed. This interspecies organ generation using blastocyst complementation (BC) is expected to be the next-generation regenerative medicine. Here, we describe the recent advances and future prospects for these two approaches.
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Affiliation(s)
- Mayuko Kano
- Stem Cell Therapy Laboratory, Advanced Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Eiji Mizutani
- Stem Cell Therapy Laboratory, Advanced Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
- Laboratory of Stem Cell Therapy, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Shota Homma
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, United States
| | - Hideki Masaki
- Stem Cell Therapy Laboratory, Advanced Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
- *Correspondence: Hiromitsu Nakauchi, ; Hideki Masaki,
| | - Hiromitsu Nakauchi
- Stem Cell Therapy Laboratory, Advanced Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, United States
- *Correspondence: Hiromitsu Nakauchi, ; Hideki Masaki,
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9
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Connolly MR, Kuravi K, Burdorf L, Sorrells L, Morrill B, Cimeno A, Vaught T, Dandro A, Sendil S, Habibabady ZA, Monahan J, Li T, LaMattina J, Eyestone W, Ayares D, Phelps C, Azimzadeh AM, Pierson RN. Humanized von Willebrand factor reduces platelet sequestration in ex vivo and in vivo xenotransplant models. Xenotransplantation 2021; 28:e12712. [PMID: 34657336 PMCID: PMC10266522 DOI: 10.1111/xen.12712] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 08/05/2021] [Accepted: 09/07/2021] [Indexed: 01/14/2023]
Abstract
The transplantation of organs across species offers the potential to solve the shortage of human organs. While activation of human platelets by human von Willebrand factor (vWF) requires vWF activation by shear stress, contact between human platelets and porcine vWF (pvWF) leads to spontaneous platelet adhesion and activation. This non-physiologic interaction may contribute to the thrombocytopenia and coagulation pathway dysregulation often associated with xenotransplantation of pig organs in nonhuman primates. Pigs genetically modified to decrease antibody and complement-dependent rejection (GTKO.hCD46) were engineered to express humanized pvWF (h*pvWF) by replacing a pvWF gene region that encodes the glycoprotein Ib-binding site with human cDNA orthologs. This modification corrected for non-physiologic human platelet aggregation on exposure to pig plasma, while preserving in vitro platelet activation by collagen. Organs from pigs with h*pvWF demonstrated reduced platelet sequestration during lung (p ≤ .01) and liver (p ≤ .038 within 4 h) perfusion ex vivo with human blood and after pig-to-baboon lung transplantation (p ≤ .007). Residual platelet sequestration and activation were not prevented by the blockade of canonical platelet adhesion pathways. The h*pvWF modification prevents physiologically inappropriate activation of human or baboon platelets by porcine vWF, addressing one cause of the thrombocytopenia and platelet activation observed with xenotransplantation.
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Affiliation(s)
- Margaret R Connolly
- Massachusetts General Hospital, Center for Transplantation Sciences, Boston, Massachusetts, USA
| | | | - Lars Burdorf
- Massachusetts General Hospital, Center for Transplantation Sciences, Boston, Massachusetts, USA
- University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | - Arielle Cimeno
- University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | - Selin Sendil
- University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Zahra A Habibabady
- Massachusetts General Hospital, Center for Transplantation Sciences, Boston, Massachusetts, USA
- University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Tiezheng Li
- University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - John LaMattina
- University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | | | - Agnes M Azimzadeh
- Massachusetts General Hospital, Center for Transplantation Sciences, Boston, Massachusetts, USA
- University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Richard N Pierson
- Massachusetts General Hospital, Center for Transplantation Sciences, Boston, Massachusetts, USA
- University of Maryland School of Medicine, Baltimore, Maryland, USA
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10
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Patel PM, Connolly MR, Coe TM, Calhoun A, Pollok F, Markmann JF, Burdorf L, Azimzadeh A, Madsen JC, Pierson RN. Minimizing Ischemia Reperfusion Injury in Xenotransplantation. Front Immunol 2021; 12:681504. [PMID: 34566955 PMCID: PMC8458821 DOI: 10.3389/fimmu.2021.681504] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 08/12/2021] [Indexed: 12/21/2022] Open
Abstract
The recent dramatic advances in preventing "initial xenograft dysfunction" in pig-to-non-human primate heart transplantation achieved by minimizing ischemia suggests that ischemia reperfusion injury (IRI) plays an important role in cardiac xenotransplantation. Here we review the molecular, cellular, and immune mechanisms that characterize IRI and associated "primary graft dysfunction" in allotransplantation and consider how they correspond with "xeno-associated" injury mechanisms. Based on this analysis, we describe potential genetic modifications as well as novel technical strategies that may minimize IRI for heart and other organ xenografts and which could facilitate safe and effective clinical xenotransplantation.
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Affiliation(s)
- Parth M. Patel
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Margaret R. Connolly
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Taylor M. Coe
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Anthony Calhoun
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Department of Surgery, Division of Cardiac Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Franziska Pollok
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - James F. Markmann
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Department of Surgery, Division of Transplantation, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Lars Burdorf
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Department of Surgery, Division of Cardiac Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Agnes Azimzadeh
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Department of Surgery, Division of Cardiac Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Joren C. Madsen
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Department of Surgery, Division of Cardiac Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Richard N. Pierson
- Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Department of Surgery, Division of Cardiac Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
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11
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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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12
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Abstract
Study of lung xenografts has proven useful to understand the remaining barriers to successful transplantation of other organ xenografts. In this chapter, the history and current status of lung xenotransplantation will be briefly reviewed, and two different experimental models, the ex vivo porcine-to-human lung perfusion and the in vivo xenogeneic lung transplantation, will be presented. We will focus on the technical details of these lung xenograft models in sufficient detail, list the needed materials, and mention analysis techniques to allow others to adopt them with minimal learning curve.
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13
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Liu F, Liu J, Yuan Z, Qing Y, Li H, Xu K, Zhu W, Zhao H, Jia B, Pan W, Guo J, Zhang X, Cheng W, Wang W, Zhao HY, Wei HJ. Generation of GTKO Diannan Miniature Pig Expressing Human Complementary Regulator Proteins hCD55 and hCD59 via T2A Peptide-Based Bicistronic Vectors and SCNT. Mol Biotechnol 2019; 60:550-562. [PMID: 29916131 DOI: 10.1007/s12033-018-0091-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Pig-to-human organ transplantation has drawn attention in recent years due to the potential use of pigs as an alternative source of human donor organs. While GGTA1 knockout (GTKO) can protect xenografts from hyperacute rejection, complement-dependent cytotoxicity might still contribute to this type of rejection. To prolong the xenograft survival, we utilized a T2A-mediated pCMV-hCD55-T2A-hCD59-Neo vector and transfected the plasmid into GTKO Diannan miniature pig fetal fibroblasts. After G418 selection combined with single-cell cloning culture, four colonies were obtained, and three of these were successfully transfected with the hCD55 and hCD59. One of the three colonies was selected as donor cells for somatic cell nuclear transfer (SCNT). Then, the reconstructed embryos were transferred into eight recipient gilts, resulting in four pregnancies. Three of the pregnant gilts delivered, yielding six piglets. Only one piglet carried hCD55 and hCD59 genetic modification. The expression levels of the GGTA1, hCD55, and hCD59 in the tissues and fibroblasts of the piglet were determined by q-PCR, fluorescence microscopy, immunohistochemical staining, and western blotting analyses. The results showed the absence of GGTA1 and the coexpression of the hCD55 and hCD59. However, the mRNA expression levels of hCD55 and hCD59 in the GTKO/hCD55/hCD59 pig fibroblasts were lower than that in human 293T cells, which may be caused by low copy number and/or CMV promoter methylation. Furthermore, we performed human complement-mediated cytolysis assays using human serum solutions from 0 to 60%. The result showed that the fibroblasts of this triple-gene modified piglet had greater survival rates than that of wild-type and GTKO controls. Taken together, these results indicate that T2A-mediated polycistronic vector system combined with SCNT can effectively generate multiplex genetically modified pigs, additional hCD55 and hCD59 expression on top of a GTKO genetic background markedly enhance the protective effect towards human serum-mediated cytolysis than those of GTKO alone. Thus, we suggest that GTKO/hCD55/hCD59 triple-gene-modified Diannan miniature pig will be a more eligible donor for xenotransplantation.
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Affiliation(s)
- Fengjuan Liu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Jinji Liu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Zaimei Yuan
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Yubo Qing
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Honghui Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Kaixiang Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
| | - Wanyun Zhu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
| | - Heng Zhao
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Baoyu Jia
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Weirong Pan
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Jianxiong Guo
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China
| | - Xuezeng Zhang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, 650201, China
| | - Wenmin Cheng
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Wei Wang
- Hunan Xeno Life Science Co., Ltd, Changsha, 410600, China.
- Institute for Cell Transplantation and Gene Therapy, The Third Xiangya Hospital Central-South University, Changsha, 410013, China.
| | - Hong-Ye Zhao
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China.
| | - Hong-Jiang Wei
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China.
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming, 650201, China.
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14
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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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15
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16
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Burdorf L, Harris D, Dahi S, Laird C, Zhang T, Ali F, Shah A, Thompson M, Braileanu G, Cheng X, Sievert E, Schwartz E, Sendil S, Parsell DM, Redding E, Phelps CJ, Ayares DL, Azimzadeh AM, Pierson RN. Thromboxane and histamine mediate PVR elevation during xenogeneic pig lung perfusion with human blood. Xenotransplantation 2018; 26:e12458. [PMID: 30175863 DOI: 10.1111/xen.12458] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/29/2018] [Accepted: 07/20/2018] [Indexed: 01/18/2023]
Abstract
BACKGROUND Elevated pulmonary vascular resistance (PVR), platelet adhesion, coagulation activation, and inflammation are prominent features of xenolung rejection. Here, we evaluate the role of thromboxane and histamine on PVR, and their contribution to other lung xenograft injury mechanisms. METHODS GalTKO.hCD46 single pig lungs were perfused ex vivo with fresh heparinized human blood: lungs were either treated with 1-Benzylimidazole (1-BIA) combined with histamine receptor blocker famotidine (n = 4) or diphenhydramine (n = 6), 1-BIA alone (n = 6) or were left untreated (n = 9). RESULTS Six of the nine control experiments (GalTKO.hCD46 untreated), "survived" until elective termination at 4 hours. Without treatment, initial PVR elevation within the first 30 minutes resolved partially over the following hour, and increased progressively during the final 2 hours of perfusion. In contrast, 1-BIA, alone or in addition to either antihistamine treatment, was associated with low stable PVR. Combined treatments significantly lowered the airway pressure when compared to untreated reference. Although platelet and neutrophil sequestration and coagulation cascade activation were not consistently altered by any intervention, increased terminal wet/dry weight ratio in untreated lungs was significantly blunted by combined treatments. CONCLUSION Combined thromboxane and histamine pathway blockade prevents PVR elevation and significantly inhibits loss of vascular barrier function when GalTKO.hCD46 lungs are perfused with human blood. Platelet activation and platelet and neutrophil sequestration persist in all groups despite efficient complement regulation, and appear to occur independent of thromboxane and histamine antagonism. Our work identifies thromboxane and histamine as key mediators of xenolung injury and defines those pathways as therapeutic targets to achieve successful xenolung transplantation.
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Affiliation(s)
- Lars Burdorf
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland.,Center for Transplantation Sciences and Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts
| | - Donald Harris
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Siamak Dahi
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Christopher Laird
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Tianshu Zhang
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Franchesca Ali
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Aakash Shah
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Mercedes Thompson
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Gheorghe Braileanu
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Xiangfei Cheng
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Evelyn Sievert
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Evan Schwartz
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Selin Sendil
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Dawn M Parsell
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Emily Redding
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland
| | - Carol J Phelps
- Center for Transplantation Sciences and Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts
| | | | - Agnes M Azimzadeh
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland.,Center for Transplantation Sciences and Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts
| | - Richard N Pierson
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, Maryland.,Center for Transplantation Sciences and Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts
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17
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Wang L, Cooper DKC, Burdorf L, Wang Y, Iwase H. Overcoming Coagulation Dysregulation in Pig Solid Organ Transplantation in Nonhuman Primates: Recent Progress. Transplantation 2018; 102:1050-1058. [PMID: 29538262 PMCID: PMC7228622 DOI: 10.1097/tp.0000000000002171] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/22/2018] [Accepted: 01/26/2018] [Indexed: 01/17/2023]
Abstract
There has recently been considerable progress in the results of pig organ transplantation in nonhuman primates, largely associated with the availability of (i) pigs genetically engineered to overcome coagulation dysregulation, and (ii) novel immunosuppressive agents. The barriers of thrombotic microangiopathy and/or consumptive coagulation were believed to be associated with (i) activation of the graft vascular endothelial cells by a low level of antipig antibody binding and/or complement deposition and/or innate immune cell activity, and (ii) molecular incompatibilities between the nonhuman primate and pig coagulation-anticoagulation systems. The introduction of a human coagulation-regulatory transgene, for example, thrombomodulin, endothelial protein C receptor, into the pig vascular endothelial cells has contributed to preventing a procoagulant state from developing, resulting in a considerable increase in graft survival. In the heterotopic (non-life-supporting) heart transplant model, graft survival has increased from a maximum of 179 days in 2005 to 945 days. After life-supporting kidney transplantation, survival has been extended from 90 days in 2004 to 499 days. In view of the more complex coagulation dysfunction seen after pig liver and, particularly, lung transplantation, progress has been less dramatic, but the maximum survival of a pig liver has been increased from 7 days in 2010 to 29 days, and of a pig lung from 4 days in 2007 to 9 days. There is a realistic prospect that the transplantation of a kidney or heart, in combination with a conventional immunosuppressive regimen, will enable long-term recipient survival.
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Affiliation(s)
- 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
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham AL
| | - Lars Burdorf
- Division of Cardiac Surgery, Department of Surgery, University of Maryland, Baltimore VAMC, Baltimore, MD
| | - Yi Wang
- Second Affiliated Hospital, University of South China, Hengyang City, Hunan, China
| | - Hayato Iwase
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham AL
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18
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Abstract
PURPOSE OF REVIEW This review describes the most recent progress in xeno lung transplantation (XLTx) to date. It describes the potential mechanisms of early xeno lung graft loss, as well as the latest therapeutic strategies to overcome them. RECENT FINDINGS Using ex-vivo perfusion models of porcine lungs with human blood, the use of genetically modified pig lungs along with novel pharmaceutical approaches has recently been studied. Strategies that have demonstrated improved lung survival include the knockout of known xenoantigens (GalTKO and N-glycolylneuraminic acid-KO), genes that regulate complement activation (hCD46 and hCD55), as well as the inflammation/coagulation cascade (human leukocyte antigen-E, human thrombomodulin, human endothelial protein C receptor, hCD47, hCD39, hCD73 and heme oxygenase-1). Furthermore, pharmacologic interventions including the depletion of pulmonary intravascular macrophages or von Willebrand factor, inhibition of thromboxane synthase and blockade of histamine receptors have also demonstrated protective effects on xeno lung grafts. Using in-vivo pig to nonhuman primate lung transplant models, these approaches have been shown to extend pulmonary xenograft survival to 5 days. SUMMARY The development of new multitransgenic GalTKO pigs has demonstrated prolongation of porcine xenograft survival; however, advancement in XLTx has remained frustratingly limited. Further intensive and innovative strategies including genetic manipulation of donors, as well as inflammation/coagulation dysregulation, are required to make XLTx a clinical possibility.
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19
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French BM, Sendil S, Sepuru KM, Ranek J, Burdorf L, Harris D, Redding E, Cheng X, Laird C, Zhao Y, Cerel B, Rajarathnam K, Pierson RN, Azimzadeh AM. Interleukin-8 mediates neutrophil-endothelial interactions in pig-to-human xenogeneic models. Xenotransplantation 2018; 25:e12385. [PMID: 29427404 PMCID: PMC5899681 DOI: 10.1111/xen.12385] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 12/21/2017] [Accepted: 01/09/2018] [Indexed: 01/13/2023]
Abstract
BACKGROUND Human neutrophils are sequestered by pig lung xenografts within minutes during ex vivo perfusion. This phenomenon is not prevented by pig genetic modifications that remove xeno-antigens or added human regulatory molecules intended to down-regulate activation of complement and coagulation pathways. This study investigated whether recipient and donor interleukin-8 (IL-8), a chemokine known to attract and activate neutrophils during inflammation, is elaborated in the context of xenogeneic injury, and whether human or pig IL-8 promote the adhesion of human neutrophils in in vitro xenograft models. METHODS Plasma levels of pig, human or non-human primate (NHP) IL-8 from ex vivo pig lung perfusion experiments (n = 10) and in vivo pig-to-baboon lung transplantation in baboons (n = 22) were analysed by ELISA or Luminex. Human neutrophils stimulated with human or pig IL-8 were analysed for CD11b expression, CD18 activation, oxidative burst and adhesion to resting or TNF-activated endothelial cells (EC) evaluated under static and flow (Bioflux) conditions. For some experiments, human neutrophils were incubated with Reparixin (IL-8/CXCL8 receptor blocker) and then analysed as in the in vitro experiments mentioned above. RESULTS Plasma levels of pig IL-8 (~6113 pg/mL) increased more than human (~1235 pg/mL) between one and four hours after initiation of ex vivo lung perfusion. However, pig IL-8 levels remained consistently low (<60 pg/mL) and NHP IL-8 plasma levels increased by ~2000 pg/mL after four hours in a pig-to-baboon lung xenotransplantation. In vitro, human neutrophils' CD11b expression, CD18 activation and oxidative burst all increased in a dose-dependent manner following exposure to either pig or human IL-8, which also were associated with increased adhesion to EC in both static and flow conditions. Reparixin inhibited human neutrophil activation by both pig and human IL-8 in a dose-dependent fashion. At 0.1 mg/mL, Reparixin inhibited the adhesion of IL-8-activated human neutrophils to pAECs by 84 ± 2.5%. CONCLUSIONS Pig IL-8 increased in an ex vivo model of pig-to-human lung xenotransplantation but is not detected in vivo, whereas human or NHP IL-8 is elevated to a similar degree in both models. Both pig and human IL-8 activate human neutrophils and increase their adhesion to pig aortic ECs, a process significantly inhibited by the addition of Reparixin to human neutrophils. This work implicates IL-8, whether of pig or human origin, as a possible factor mediating in lung xenograft inflammation and injury and supports the evaluation of therapeutic targeting of this pathway in the context of xenotransplantation.
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Affiliation(s)
- Beth M. French
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Selin Sendil
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Krishna Mohan Sepuru
- Department of Biochemistry and Molecular Biology, Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555
| | - Jolene Ranek
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Lars Burdorf
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Donald Harris
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Emily Redding
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Xiangfei Cheng
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Christopher Laird
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Yuming Zhao
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Benjamin Cerel
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Krishna Rajarathnam
- Department of Biochemistry and Molecular Biology, Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555
| | - Richard N Pierson
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
| | - Agnes M. Azimzadeh
- Department of Surgery, University of Maryland School of Medicine, and VAMC Baltimore, MD
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Abstract
PURPOSE OF REVIEW This article reviews recent progress in the field of lung xenotransplantation, including mechanisms of xenograft injury, and the influence of mechanism-directed genetic modifications and other interventions that may soon enable therapeutic use of pig lungs in humans. RECENT FINDINGS An extensive series of lung xenotransplantation experiments demonstrates that multiple genetic modifications targeting known xenogeneic lung injury mechanisms are associated with incremental improvements in lung survival or function. Addition of human complement (hCD46, hCD55), coagulation (hEPCR, hTBM, hTFPI, hCD39), or anti-inflammatory pathway regulatory genes (HO-1, HLA-E), and GalT and Neu5Gc gene knockout has each demonstrated protective effects on lung survival or function. In addition, drug treatments targeting key inflammatory and clotting pathways have been shown to attenuate residual mechanisms of lung injury. Work with other pig organs in primate models show that regimens based on costimulatory pathway blocking antibodies prolong xenograft function for months to years, suggesting that once initial lung inflammation mechanisms are fully controlled, clinically useful application of pig lung xenografts may soon be feasible. SUMMARY Genetic modification of pigs coupled with drugs targeting complement activation, coagulation, and inflammation have significantly increased duration of pig lung function in ex-vivo human blood perfusion models, and life-supporting lung xenograft survival in vivo.
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Affiliation(s)
- Chris Laird
- aDivision of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine bVA Maryland Healthcare System, Baltimore, Maryland, USA
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21
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Puga Yung G, Bongoni AK, Pradier A, Madelon N, Papaserafeim M, Sfriso R, Ayares DL, Wolf E, Klymiuk N, Bähr A, Constantinescu MA, Voegelin E, Kiermeir D, Jenni H, Rieben R, Seebach JD. Release of pig leukocytes and reduced human NK cell recruitment during ex vivo perfusion of HLA-E/human CD46 double-transgenic pig limbs with human blood. Xenotransplantation 2017; 25. [PMID: 29057510 DOI: 10.1111/xen.12357] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 08/15/2017] [Accepted: 09/01/2017] [Indexed: 12/25/2022]
Abstract
BACKGROUND In pig-to-human xenotransplantation, interactions between human natural killer (NK) cells and porcine endothelial cells (pEC) are characterized by recruitment and cytotoxicity. Protection from xenogeneic NK cytotoxicity can be achieved in vitro by the expression of the non-classical human leukocyte antigen-E (HLA-E) on pEC. Thus, the aim of this study was to analyze NK cell responses to vascularized xenografts using an ex vivo perfusion system of pig limbs with human blood. METHODS Six pig forelimbs per group, respectively, stemming from either wild-type (wt) or HLA-E/hCD46 double-transgenic (tg) animals, were perfused ex vivo with heparinized human blood for 12 hours. Blood samples were collected at defined time intervals, cell numbers counted, and peripheral blood mononuclear cells analyzed for phenotype by flow cytometry. Muscle biopsies were analyzed for NK cell infiltration. In vitro NK cytotoxicity assays were performed using pEC derived from wt and tg animals as target cells. RESULTS Ex vivo, a strong reduction in circulating human CD45 leukocytes was observed after 60 minutes of xenoperfusion in both wt and tg limb groups. NK cell numbers dropped significantly. Within the first 10 minutes, the decrease in NK cells was more significant in the wt limb perfusions as compared to tg limbs. Immunohistology of biopsies taken after 12 hours showed less NK cell tissue infiltration in the tg limbs. In vitro, NK cytotoxicity against hCD46 single tg pEC and wt pEC was similar, while lysis of double tg HLA-E/hCD46 pEC was significantly reduced. Finally, circulating cells of pig origin were observed during the ex vivo xenoperfusions. These cells expressed phenotypes mainly of monocytes, B and T lymphocytes, NK cells, as well as some activated endothelial cells. CONCLUSIONS Ex vivo perfusion of pig forelimbs using whole human blood represents a powerful tool to study humoral and early cell-mediated rejection mechanisms of vascularized pig-to-human xenotransplantation, although there are several limitations of the model. Here, we show that (i) transgenic expression of HLA-E/hCD46 in pig limbs provides partial protection from human NK cell-mediated xeno responses and (ii) the emergence of a pig cell population during xenoperfusions with implications for the immunogenicity of xenografts.
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Affiliation(s)
- Gisella Puga Yung
- Division of Immunology and Allergology, University Hospital and Medical Faculty, Geneva, Switzerland
| | - Anjan K Bongoni
- Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Amandine Pradier
- Division of Immunology and Allergology, University Hospital and Medical Faculty, Geneva, Switzerland
| | - Natacha Madelon
- Division of Immunology and Allergology, University Hospital and Medical Faculty, Geneva, Switzerland
| | - Maria Papaserafeim
- Division of Immunology and Allergology, University Hospital and Medical Faculty, Geneva, Switzerland
| | - Riccardo Sfriso
- Department of Clinical Research, University of Bern, Bern, Switzerland
| | | | - Eckhard Wolf
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilian University, Munich, Germany
| | - Nikolai Klymiuk
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilian University, Munich, Germany
| | - Andrea Bähr
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilian University, Munich, Germany
| | | | - Esther Voegelin
- Clinic of Plastic and Hand Surgery, University Hospital, Bern, Switzerland
| | - David Kiermeir
- Clinic of Plastic and Hand Surgery, University Hospital, Bern, Switzerland
| | - Hansjörg Jenni
- Clinic of Cardiovascular Surgery, University Hospital, Bern, Switzerland
| | - Robert Rieben
- Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Jörg D Seebach
- Division of Immunology and Allergology, University Hospital and Medical Faculty, Geneva, Switzerland
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French BM, Sendil S, Pierson RN, Azimzadeh AM. The role of sialic acids in the immune recognition of xenografts. Xenotransplantation 2017; 24. [PMID: 29057592 PMCID: PMC10167934 DOI: 10.1111/xen.12345] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 07/05/2017] [Accepted: 08/14/2017] [Indexed: 12/11/2022]
Abstract
Presentation of sialic acid (Sia) varies among different tissues and organs within each species, and between species. This diversity has biologically important consequences regarding the recognition of cells by "xeno" antibodies (Neu5Gc vs Neu5Ac). Sia also plays a central role in inflammation by influencing binding of the asialoglycoprotein receptor 1 (ASGR-1), Siglec-1 (Sialoadhesin), and cellular interactions mediated by the selectin, integrin, and galectin receptor families. This review will focus on what is known about basic Sia structure and function in association with xenotransplantation, how changes in sialylation may occur in this context (through desialylation or changes in sialyltransferases), and how this fundamental pathway modulates adhesive and cell activation pathways that appear to be particularly crucial to homeostasis and inflammation for xenografts.
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Affiliation(s)
- Beth M French
- Division of Cardiac Surgery, University of Maryland Baltimore, School of Medicine, and VAMC, Baltimore, MD, USA
| | - Selin Sendil
- Division of Cardiac Surgery, University of Maryland Baltimore, School of Medicine, and VAMC, Baltimore, MD, USA
| | - Richard N Pierson
- Division of Cardiac Surgery, University of Maryland Baltimore, School of Medicine, and VAMC, Baltimore, MD, USA
| | - Agnes M Azimzadeh
- Division of Cardiac Surgery, University of Maryland Baltimore, School of Medicine, and VAMC, Baltimore, MD, USA
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Gao C, McDowell IC, Zhao S, Brown CD, Engelhardt BE. Context Specific and Differential Gene Co-expression Networks via Bayesian Biclustering. PLoS Comput Biol 2016; 12:e1004791. [PMID: 27467526 PMCID: PMC4965098 DOI: 10.1371/journal.pcbi.1004791] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 02/03/2016] [Indexed: 01/15/2023] Open
Abstract
Identifying latent structure in high-dimensional genomic data is essential for exploring biological processes. Here, we consider recovering gene co-expression networks from gene expression data, where each network encodes relationships between genes that are co-regulated by shared biological mechanisms. To do this, we develop a Bayesian statistical model for biclustering to infer subsets of co-regulated genes that covary in all of the samples or in only a subset of the samples. Our biclustering method, BicMix, allows overcomplete representations of the data, computational tractability, and joint modeling of unknown confounders and biological signals. Compared with related biclustering methods, BicMix recovers latent structure with higher precision across diverse simulation scenarios as compared to state-of-the-art biclustering methods. Further, we develop a principled method to recover context specific gene co-expression networks from the estimated sparse biclustering matrices. We apply BicMix to breast cancer gene expression data and to gene expression data from a cardiovascular study cohort, and we recover gene co-expression networks that are differential across ER+ and ER- samples and across male and female samples. We apply BicMix to the Genotype-Tissue Expression (GTEx) pilot data, and we find tissue specific gene networks. We validate these findings by using our tissue specific networks to identify trans-eQTLs specific to one of four primary tissues.
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Affiliation(s)
- Chuan Gao
- Department of Statistical Science, Duke University, Durham, North Carolina, United States of America
| | - Ian C. McDowell
- Program in Computational Biology and Bioinformatics, Duke University, Durham, North Carolina, United States of America
| | - Shiwen Zhao
- Program in Computational Biology and Bioinformatics, Duke University, Durham, North Carolina, United States of America
| | - Christopher D. Brown
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Barbara E. Engelhardt
- Department of Computer Science, Center for Statistics and Machine Learning, Princeton University, Princeton, New Jersey, United States of America
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24
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Burdorf L, Riner A, Rybak E, Salles II, De Meyer SF, Shah A, Quinn KJ, Harris D, Zhang T, Parsell D, Ali F, Schwartz E, Kang E, Cheng X, Sievert E, Zhao Y, Braileanu G, Phelps CJ, Ayares DL, Deckmyn H, Pierson RN, Azimzadeh AM, Dandro A, Karavi K. Platelet sequestration and activation during GalTKO.hCD46 pig lung perfusion by human blood is primarily mediated by GPIb, GPIIb/IIIa, and von Willebrand Factor. Xenotransplantation 2016; 23:222-236. [PMID: 27188532 DOI: 10.1111/xen.12236] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 03/17/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Here, we ask whether platelet GPIb and GPIIb/IIIa receptors modulate platelet sequestration and activation during GalTKO.hCD46 pig lung xenograft perfusion. METHODS GalTKO.hCD46 transgenic pig lungs were perfused with heparinized fresh human blood. Results from perfusions in which αGPIb Fab (6B4, 10 mg/l blood, n = 6), αGPIIb/IIIa Fab (ReoPro, 3.5 mg/l blood, n = 6), or both drugs (n = 4) were administered to the perfusate were compared to two additional groups in which the donor pig received 1-desamino-8-d-arginine vasopressin (DDAVP), 3 μg/kg (to pre-deplete von Willebrand Factor (pVWF), the main GPIb ligand), with or without αGPIb (n = 6 each). RESULTS Platelet sequestration was significantly delayed in αGPIb, αGPIb+DDAVP, and αGPIb+αGPIIb/IIIa groups. Median lung "survival" was significantly longer (>240 vs. 162 min reference, p = 0.016), and platelet activation (as CD62P and βTG) were significantly inhibited, when pigs were pre-treated with DDAVP, with or without αGPIb Fab treatment. Pulmonary vascular resistance rise was not significantly attenuated in any group, and was associated with residual thromboxane and histamine elaboration. CONCLUSIONS The GPIb-VWF and GPIIb/IIIa axes play important roles in platelet sequestration and coagulation cascade activation during GalTKO.hCD46 lung xenograft injury. GPIb blockade significantly reduces platelet activation and delays platelet sequestration in this xenolung rejection model, an effect amplified by adding αGPIIb/IIIa blockade or depletion of VWF from pig lung.
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Affiliation(s)
- L Burdorf
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - A Riner
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - E Rybak
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - I I Salles
- Laboratory for Thrombosis Research, IRF-Ls, Kulak KU Leuven, Belgium.,Centre for Hematology, Imperial College London, UK
| | - S F De Meyer
- Laboratory for Thrombosis Research, IRF-Ls, Kulak KU Leuven, Belgium
| | - A Shah
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - K J Quinn
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - D Harris
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - T Zhang
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - D Parsell
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - F Ali
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - E Schwartz
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - E Kang
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - X Cheng
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - E Sievert
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - Y Zhao
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - G Braileanu
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - C J Phelps
- Revivicor, Inc., Blacksburg, VA, United States
| | - D L Ayares
- Revivicor, Inc., Blacksburg, VA, United States
| | - H Deckmyn
- Laboratory for Thrombosis Research, IRF-Ls, Kulak KU Leuven, Belgium
| | - R N Pierson
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - A M Azimzadeh
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
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25
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Cooper DKC, Ezzelarab MB, Hara H, Iwase H, Lee W, Wijkstrom M, Bottino R. The pathobiology of pig-to-primate xenotransplantation: a historical review. Xenotransplantation 2016; 23:83-105. [PMID: 26813438 DOI: 10.1111/xen.12219] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/22/2015] [Indexed: 12/16/2022]
Abstract
The immunologic barriers to successful xenotransplantation are related to the presence of natural anti-pig antibodies in humans and non-human primates that bind to antigens expressed on the transplanted pig organ (the most important of which is galactose-α1,3-galactose [Gal]), and activate the complement cascade, which results in rapid destruction of the graft, a process known as hyperacute rejection. High levels of elicited anti-pig IgG may develop if the adaptive immune response is not prevented by adequate immunosuppressive therapy, resulting in activation and injury of the vascular endothelium. The transplantation of organs and cells from pigs that do not express the important Gal antigen (α1,3-galactosyltransferase gene-knockout [GTKO] pigs) and express one or more human complement-regulatory proteins (hCRP, e.g., CD46, CD55), when combined with an effective costimulation blockade-based immunosuppressive regimen, prevents early antibody-mediated and cellular rejection. However, low levels of anti-non-Gal antibody and innate immune cells and/or platelets may initiate the development of a thrombotic microangiopathy in the graft that may be associated with a consumptive coagulopathy in the recipient. This pathogenic process is accentuated by the dysregulation of the coagulation-anticoagulation systems between pigs and primates. The expression in GTKO/hCRP pigs of a human coagulation-regulatory protein, for example, thrombomodulin, is increasingly being associated with prolonged pig graft survival in non-human primates. Initial clinical trials of islet and corneal xenotransplantation are already underway, and trials of pig kidney or heart transplantation are anticipated within the next few years.
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Affiliation(s)
- David K C Cooper
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mohamed B Ezzelarab
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hidetaka Hara
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hayato Iwase
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Whayoung Lee
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Martin Wijkstrom
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Rita Bottino
- Institute for Cellular Therapeutics, Allegheny-Singer Research Institute, Pittsburgh, PA, USA
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26
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Ezzelarab MB, Ayares D, Cooper DKC. Transgenic expression of human CD46: does it reduce the primate T-cell response to pig endothelial cells? Xenotransplantation 2015; 22:487-9. [PMID: 26584837 DOI: 10.1111/xen.12209] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Mohamed B Ezzelarab
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
| | | | - David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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27
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Cooper DKC, Bottino R. Recent advances in understanding xenotransplantation: implications for the clinic. Expert Rev Clin Immunol 2015; 11:1379-90. [PMID: 26548357 PMCID: PMC4879962 DOI: 10.1586/1744666x.2015.1083861] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The results of organ and cell allotransplantation continue to improve, but the field remains limited by a lack of deceased donor organs. Xenotransplantation, for example, between pig and human, offers unlimited organs and cells for clinical transplantation. The immune barriers include a strong innate immune response in addition to the adaptive T-cell response. The innate response has largely been overcome by the transplantation of organs from pigs with genetic modifications that protect their tissues from this response. T-cell-mediated rejection can be controlled by immunosuppressive agents that inhibit costimulation. Coagulation dysfunction between the pig and primate remains problematic but is being overcome by the transplantation of organs from pigs that express human coagulation-regulatory proteins. The remaining barriers will be resolved by the introduction of novel genetically-engineered pigs. Limited clinical trials of pig islet and corneal transplantation are already underway.
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Affiliation(s)
- David K. C. Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA
| | - Rita Bottino
- Institute of Cellular Therapeutics, Allegheny-Singer Research Institute, Pittsburgh, PA
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28
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Azimzadeh AM, Kelishadi SS, Ezzelarab MB, Singh AK, Stoddard T, Iwase H, Zhang T, Burdorf L, Sievert E, Avon C, Cheng X, Ayares D, Horvath KA, Corcoran PC, Mohiuddin MM, Barth RN, Cooper DKC, Pierson RN. Early graft failure of GalTKO pig organs in baboons is reduced by expression of a human complement pathway-regulatory protein. Xenotransplantation 2015; 22:310-6. [PMID: 26174749 DOI: 10.1111/xen.12176] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/07/2015] [Indexed: 01/24/2023]
Abstract
We describe the incidence of early graft failure (EGF, defined as loss of function from any cause within 3 days after transplant) in a large cohort of GalTKO pig organs transplanted into baboons in three centers, and the effect of additional expression of a human complement pathway-regulatory protein, CD46 or CD55 (GalTKO.hCPRP). Baboon recipients of life-supporting GalTKO kidney (n = 7) or heterotopic heart (n = 14) grafts received either no immunosuppression (n = 4), or one of several partial or full immunosuppressive regimens (n = 17). Fourteen additional baboons received a GalTKO.hCPRP kidney (n = 5) or heart (n = 9) and similar treatment regimens. Immunologic, pathologic, and coagulation parameters were measured at frequent intervals. EGF of GalTKO organs occurred in 9/21 baboons (43%). hCPRP expression reduced the GalTKO EGF incidence to 7% (1/14; P < 0.01 vs. GalTKO alone). At 30 mins, complement deposits were more intense in organs in which EGF developed (P < 0.005). The intensity of peri-transplant platelet activation (as β-thromboglobulin release) correlated with EGF, as did the cumulative coagulation score (P < 0.01). We conclude that (i) the transgenic expression of a hCPRP on the vascular endothelium of a GalTKO pig reduces the incidence of EGF and reduces complement deposition, (ii) complement deposition and platelet activation correlate with early GalTKO organ failure, and (iii) the expression of a hCPRP reduces EGF but does not prevent systemic coagulation activation. Additional strategies will be required to control coagulation activation.
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Affiliation(s)
- Agnes M Azimzadeh
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
| | - Sean S Kelishadi
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
| | - Mohamed B Ezzelarab
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Avneesh K Singh
- Cardiothoracic Surgery Research Program, NHLBI/NIH, Bethesda, MD, USA
| | - Tiffany Stoddard
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
| | - Hayato Iwase
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tianshu Zhang
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
| | - Lars Burdorf
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
| | - Evelyn Sievert
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
| | - Chris Avon
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
| | - Xiangfei Cheng
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
| | | | - Keith A Horvath
- Cardiothoracic Surgery Research Program, NHLBI/NIH, Bethesda, MD, USA
| | - Philip C Corcoran
- Cardiothoracic Surgery Research Program, NHLBI/NIH, Bethesda, MD, USA
| | | | - Rolf N Barth
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
| | - David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Richard N Pierson
- University of Maryland School of Medicine and Baltimore VAMC, Baltimore, MD, USA
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Harris DG, Benipal PK, Cheng X, Burdorf L, Azimzadeh AM, Pierson RN. Four-dimensional characterization of thrombosis in a live-cell, shear-flow assay: development and application to xenotransplantation. PLoS One 2015; 10:e0123015. [PMID: 25830912 PMCID: PMC4382176 DOI: 10.1371/journal.pone.0123015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 02/26/2015] [Indexed: 02/01/2023] Open
Abstract
Background Porcine xenografts are a promising source of scarce transplantable organs, but stimulate intense thrombosis of human blood despite targeted genetic and pharmacologic interventions. Current experimental models do not enable study of the blood/endothelial interface to investigate adhesive interactions and thrombosis at the cellular level under physiologic conditions. The purpose of this study was to develop and validate a live-cell, shear-flow based thrombosis assay relevant to general thrombosis research, and demonstrate its potential in xenotransplantation applications. Methodology/Principal Findings Confluent wild-type (WT, n = 48) and Gal transferase knock-out (GalTKO, which resist hyperacute rejection; n = 11) porcine endothelia were cultured in microfluidic channels. To mimic microcirculatory flow, channels were perfused at 5 dynes/cm2 and 37°C with human blood stained to fluorescently label platelets. Serial fluorescent imaging visualized percent surface area coverage (SA, for adhesion of labeled cells) and total fluorescence (a metric of clot volume). Aggregation was calculated by the fluorescence/SA ratio (FR). WT endothelia stimulated diffuse platelet adhesion (SA 65 ± 2%) and aggregation (FR 120 ± 1 a.u.), indicating high-grade thrombosis consistent with the rapid platelet activation and consumption seen in whole-organ lung xenotransplantation models. Experiments with antibody blockade of platelet aggregation, and perfusion of syngeneic and allo-incompatible endothelium was used to verify the biologic specificity and validity of the assay. Finally, with GalTKO endothelia thrombus volume decreased by 60%, due primarily to a 58% reduction in adhesion (P < 0.0001 each); importantly, aggregation was only marginally affected (11% reduction, P < 0.0001). Conclusions/Significance This novel, high-throughput assay enabled dynamic modeling of whole-blood thrombosis on intact endothelium under physiologic conditions, and allowed mechanistic characterization of endothelial and platelet interactions. Applied to xenogeneic thrombosis, it enables future studies regarding the effect of modifying the porcine genotype on sheer-stress-dependent events that characterize xenograft injury. This in-vitro platform is likely to prove broadly useful to study thrombosis and endothelial interactions under dynamic physiologic conditions.
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Affiliation(s)
- Donald G Harris
- Division of General Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America; Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Prabhjot K Benipal
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Xiangfei Cheng
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Lars Burdorf
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Agnes M Azimzadeh
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Richard N Pierson
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America; Surgical Care Clinical Center, VA Maryland Health Care System, Baltimore, Maryland, United States of America
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Harris DG, Quinn KJ, French BM, Schwartz E, Kang E, Dahi S, Phelps CJ, Ayares DL, Burdorf L, Azimzadeh AM, Pierson RN. Meta-analysis of the independent and cumulative effects of multiple genetic modifications on pig lung xenograft performance during ex vivo perfusion with human blood. Xenotransplantation 2015; 22:102-11. [PMID: 25470239 PMCID: PMC4390422 DOI: 10.1111/xen.12149] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 11/01/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND Genetically modified pigs are a promising potential source of lung xenografts. Ex vivo xenoperfusion is an effective platform for testing the effect of new modifications, but typical experiments are limited by testing of a single genetic intervention and small sample sizes. The purpose of this study was to analyze the individual and aggregate effects of donor genetic modifications on porcine lung xenograft survival and injury in an extensive pig lung xenoperfusion series. METHODS Data from 157 porcine lung xenoperfusion experiments using otherwise unmodified heparinized human blood were aggregated as either continuous or dichotomous variables. Lungs were wild type in 17 perfusions (11% of the study group), while 31 lungs (20% of the study group) had one genetic modification, 40 lungs (39%) had 2, and 47 lungs (30%) had 3 or more modifications. The primary endpoint was functional lung survival to 4 h of perfusion. Secondary analyses evaluated previously identified markers associated with known lung xenograft injury mechanisms. In addition to comparison among all xenografts grouped by survival status, a subgroup analysis was performed of lungs incorporating the GalTKO.hCD46 genotype. RESULTS Each increase in the number of genetic modifications was associated with additional prolongation of lung xenograft survival. Lungs that exhibited survival to 4 h generally had reduced platelet activation and thrombin generation. GalTKO and the expression of hCD46, HO-1, hCD55, or hEPCR were associated with improved survival. hTBM, HLA-E, and hCD39 were associated with no significant effect on the primary outcome. CONCLUSION This meta-analysis of an extensive lung xenotransplantation series demonstrates that increasing the number of genetic modifications targeting known xenogeneic lung injury mechanisms is associated with incremental improvements in lung survival. While more detailed mechanistic studies are needed to explore the relationship between gene expression and pathway-specific injury and explore why some genes apparently exhibit neutral (hTBM, HLA-E) or inconclusive (CD39) effects, GalTKO, hCD46, HO-1, hCD55, and hEPCR modifications were associated with significant lung xenograft protection. This analysis supports the hypothesis that multiple genetic modifications targeting different known mechanisms of xenograft injury will be required to optimize lung xenograft survival.
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Affiliation(s)
- Donald G. Harris
- Department of Surgery, University of Maryland School of Medicine. Baltimore, MD
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine. Baltimore, MD
| | - Kevin J. Quinn
- Department of Surgery, University of Maryland School of Medicine. Baltimore, MD
| | - Beth M. French
- Department of Surgery, University of Maryland School of Medicine. Baltimore, MD
| | - Evan Schwartz
- Department of Surgery, University of Maryland School of Medicine. Baltimore, MD
| | - Elizabeth Kang
- Department of Surgery, University of Maryland School of Medicine. Baltimore, MD
| | - Siamak Dahi
- Department of Surgery, University of Maryland School of Medicine. Baltimore, MD
| | | | | | - Lars Burdorf
- Department of Surgery, University of Maryland School of Medicine. Baltimore, MD
| | - Agnes M. Azimzadeh
- Department of Surgery, University of Maryland School of Medicine. Baltimore, MD
| | - Richard N. Pierson
- Department of Surgery, University of Maryland School of Medicine. Baltimore, MD
- Surgical Care Clinical Center, VA Maryland Health Care Center. Baltimore, MD
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Abstract
The availability of organs and cells from deceased humans for transplantation is not meeting the demand. Xenotransplantation, specifically the transplantation of organs and cells from genetically engineered pigs, could resolve this problem. Diabetic monkeys have remained normoglycemic and insulin-independent after pig islet transplantation for >one yr, and a pig heterotopic (non-life-supporting) heart transplant recently reached the one-yr milestone in a baboon. With these encouraging results, why is it that, with some notable exceptions, research into xenotransplantation has received relatively little support by industry, government funding agencies, and medical charitable foundations? Industry appears reluctant to support research that will take more than two to three yr to come to clinical trial, and the funding agencies appear to have been "distracted" by the current appeal of stem cell technology and regenerative medicine. It has only been the willingness of living donors to provide organs that has significantly increased the number of transplants being performed worldwide. These altruistic donations are not without risk of morbidity and even mortality to the donor. Although with the best of intentions, we are therefore traversing the Hippocratic Oath of doctors to "do no harm." This should be a stimulus to fund exploration of alternative approaches, including xenotransplantation.
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Affiliation(s)
- David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
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Abstract
The first transgenic pigs were generated for agricultural purposes about three decades ago. Since then, the micromanipulation techniques of pig oocytes and embryos expanded from pronuclear injection of foreign DNA to somatic cell nuclear transfer, intracytoplasmic sperm injection-mediated gene transfer, lentiviral transduction, and cytoplasmic injection. Mechanistically, the passive transgenesis approach based on random integration of foreign DNA was developed to active genetic engineering techniques based on the transient activity of ectopic enzymes, such as transposases, recombinases, and programmable nucleases. Whole-genome sequencing and annotation of advanced genome maps of the pig complemented these developments. The full implementation of these tools promises to immensely increase the efficiency and, in parallel, to reduce the costs for the generation of genetically engineered pigs. Today, the major application of genetically engineered pigs is found in the field of biomedical disease modeling. It is anticipated that genetically engineered pigs will increasingly be used in biomedical research, since this model shows several similarities to humans with regard to physiology, metabolism, genome organization, pathology, and aging.
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Affiliation(s)
- Gökhan Gün
- Department of Biotechnology, Friedrich-Loeffler-Institut, Institut für Nutztiergenetik, Mariensee, Neustadt, Germany
- Molecular Biology & Genetics, Istanbul Technical University, Istanbul, Turkey
- Histology and Embryology Department, Faculty of Veterinary Medicine, Istanbul University, Istanbul, Turkey
| | - Wilfried A. Kues
- Department of Biotechnology, Friedrich-Loeffler-Institut, Institut für Nutztiergenetik, Mariensee, Neustadt, Germany
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Burlak C, Hoang QQ. Xenotransplantation literature update, May-June 2014. Xenotransplantation 2014; 21:392-5. [PMID: 25041534 DOI: 10.1111/xen.12128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 06/16/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher Burlak
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
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Harris DG, Quinn KJ, Dahi S, Burdorf L, Azimzadeh AM, Pierson RN. Lung xenotransplantation: recent progress and current status. Xenotransplantation 2014; 21:496-506. [PMID: 25040467 DOI: 10.1111/xen.12116] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 05/05/2014] [Indexed: 12/22/2022]
Abstract
Xenotransplantation has undergone important progress in controlling initial hyperacute rejection in many preclinical models, with some cell, tissue, and organ xenografts advancing toward clinical trials. However, acute injury, driven primarily by innate immune and inflammatory responses, continues to limit results in lung xenograft models. The purpose of this article is to review the current status of lung xenotransplantation--including the seemingly unique challenges posed by this organ-and summarize proven and emerging means of overcoming acute lung xenograft injury.
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Affiliation(s)
- Donald G Harris
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA; Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD, USA
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