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Pan W, Zhang W, Zheng B, Camellato BR, Stern J, Lin Z, Khodadadi-Jamayran A, Kim J, Sommer P, Khalil K, Weldon E, Bai J, Zhu Y, Meyn P, Heguy A, Mangiola M, Griesemer A, Keating BJ, Montgomery RA, Xia B, Boeke JD. Cellular dynamics in pig-to-human kidney xenotransplantation. MED 2024:S2666-6340(24)00207-1. [PMID: 38776915 DOI: 10.1016/j.medj.2024.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 01/30/2024] [Accepted: 05/06/2024] [Indexed: 05/25/2024]
Abstract
BACKGROUND Xenotransplantation of genetically engineered porcine organs has the potential to address the challenge of organ donor shortage. Two cases of porcine-to-human kidney xenotransplantation were performed, yet the physiological effects on the xenografts and the recipients' immune responses remain largely uncharacterized. METHODS We performed single-cell RNA sequencing (scRNA-seq) and longitudinal RNA-seq analyses of the porcine kidneys to dissect xenotransplantation-associated cellular dynamics and xenograft-recipient interactions. We additionally performed longitudinal scRNA-seq of the peripheral blood mononuclear cells (PBMCs) to detect recipient immune responses across time. FINDINGS Although no hyperacute rejection signals were detected, scRNA-seq analyses of the xenografts found evidence of endothelial cell and immune response activation, indicating early signs of antibody-mediated rejection. Tracing the cells' species origin, we found human immune cell infiltration in both xenografts. Human transcripts in the longitudinal bulk RNA-seq revealed that human immune cell infiltration and the activation of interferon-gamma-induced chemokine expression occurred by 12 and 48 h post-xenotransplantation, respectively. Concordantly, longitudinal scRNA-seq of PBMCs also revealed two phases of the recipients' immune responses at 12 and 48-53 h. Lastly, we observed global expression signatures of xenotransplantation-associated kidney tissue damage in the xenografts. Surprisingly, we detected a rapid increase of proliferative cells in both xenografts, indicating the activation of the porcine tissue repair program. CONCLUSIONS Longitudinal and single-cell transcriptomic analyses of porcine kidneys and the recipient's PBMCs revealed time-resolved cellular dynamics of xenograft-recipient interactions during xenotransplantation. These cues can be leveraged for designing gene edits and immunosuppression regimens to optimize xenotransplantation outcomes. FUNDING This work was supported by NIH RM1HG009491 and DP5OD033430.
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Affiliation(s)
- Wanqing Pan
- Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California Keck School of Medicine, Los Angeles, CA 90033, USA
| | - Weimin Zhang
- Institute for Systems Genetics, NYU Langone Health, New York, NY 10016, USA; Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Binghan Zheng
- Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Brendan R Camellato
- Institute for Systems Genetics, NYU Langone Health, New York, NY 10016, USA; Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Jeffrey Stern
- NYU Langone Transplant Institute, NYU Langone Health, New York, NY 10016, USA; Department of Surgery, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Ziyan Lin
- Applied Bioinformatics Laboratories (ABL), NYU Grossman School of Medicine, New York, NY 10016, USA
| | | | - Jacqueline Kim
- NYU Langone Transplant Institute, NYU Langone Health, New York, NY 10016, USA; Department of Surgery, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Philip Sommer
- Department of Anesthesiology, Perioperative Care & Pain Medicine, NYU Langone Health, New York, NY 10016, USA
| | - Karen Khalil
- NYU Langone Transplant Institute, NYU Langone Health, New York, NY 10016, USA
| | - Elaina Weldon
- NYU Langone Transplant Institute, NYU Langone Health, New York, NY 10016, USA; Department of Surgery, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Jiangshan Bai
- Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Yinan Zhu
- Institute for Systems Genetics, NYU Langone Health, New York, NY 10016, USA; Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Peter Meyn
- Genome Technology Center, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Adriana Heguy
- Genome Technology Center, NYU Grossman School of Medicine, New York, NY 10016, USA; Department of Pathology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Massimo Mangiola
- NYU Langone Transplant Institute, NYU Langone Health, New York, NY 10016, USA
| | - Adam Griesemer
- NYU Langone Transplant Institute, NYU Langone Health, New York, NY 10016, USA; Department of Surgery, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Brendan J Keating
- Institute for Systems Genetics, NYU Langone Health, New York, NY 10016, USA; NYU Langone Transplant Institute, NYU Langone Health, New York, NY 10016, USA; Department of Surgery, NYU Grossman School of Medicine, New York, NY 10016, USA; Penn Transplant Institute, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Robert A Montgomery
- NYU Langone Transplant Institute, NYU Langone Health, New York, NY 10016, USA; Department of Surgery, NYU Grossman School of Medicine, New York, NY 10016, USA.
| | - Bo Xia
- Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Institute for Systems Genetics, NYU Langone Health, New York, NY 10016, USA; Society of Fellows, Harvard University, Cambridge, MA 02138, USA.
| | - Jef D Boeke
- Institute for Systems Genetics, NYU Langone Health, New York, NY 10016, USA; Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA.
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Swatek AM, Parekh KR. Lung Xenotransplantation. Thorac Surg Clin 2023; 33:291-297. [PMID: 37414485 DOI: 10.1016/j.thorsurg.2023.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Although efforts have been made to expand the pool of donor lung allografts for human lung transplantation, a shortage remains. Lung xenotransplantation has been proposed as an alternative approach, but lung xenotransplantation in humans has not yet been reported. In addition, significant biological and ethical barriers will have to be addressed before clinical trials can be undertaken. However, significant progress has been made toward addressing biological incompatibilities that present a barrier, and recent advances in genetic engineering tools promise to accelerate further progress.
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Affiliation(s)
- Anthony M Swatek
- Department of Cardiothoracic Surgery, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, SE500GH, Iowa City, IA 52242, USA
| | - Kalpaj R Parekh
- Department of Cardiothoracic Surgery, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, SE500GH, Iowa City, IA 52242, USA.
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3
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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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4
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Cimeno A, Kuravi K, Sorrells L, Dandro A, Sendil S, Burdorf L, Parsell DM, Eyestone W, Phelps C, Ayares D, Azimzadeh AM, Pierson RN, Barth RN, LaMattina JC. hEPCR.hTBM.hCD47.hHO-1 with donor clodronate and DDAVP treatment improves perfusion and function of GalTKO.hCD46 porcine livers perfused with human blood. Xenotransplantation 2022; 29:e12731. [PMID: 35166407 PMCID: PMC10249003 DOI: 10.1111/xen.12731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 07/15/2021] [Accepted: 01/12/2022] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Platelet sequestration, inflammation, and inappropriate coagulation cascade activation are prominent in liver xenotransplant models and are associated with poor outcomes. Here, we evaluate a cassette of six additional genetic modifications to reduce anti-pig antibody binding (α-1,3-galactosyl transferase knockout [GalTKO]) and target coagulation dysregulation (human endothelial protein C receptor [hEPRC] and thrombomodulin [hTBM]), complement pathway regulation (human membrane cofactor protein, hCD46), inflammation heme oxygenase 1 [hHO-1]), and a self-recognition receptor (integrin-associated protein [hCD47]), as well as donor pharmacologic treatments designed to blunt these phenomena. METHODS Livers from GaltKO.hCD46 pigs ("2-gene," n = 3) and GalTKO.hCD46 pigs also transgenic for hEPRC, hTBM, hCD47, and hHO-1 ("6-gene," n = 4) were perfused ex vivo with whole human blood. Six-gene pigs were additionally pretreated with desmopressin (DDAVP) and clodronate liposomes to deplete vWF and kupffer cells, respectively. RESULTS The average perfusion times increased from 304 (±148) min in the 2-gene group to 856 (±61) min in the 6-gene group (p = .010). The average heparin administration was decreased from 8837 U/h in the 2-gene to 1354 U/h in the 6-gene group (p = .047). Platelet sequestration tended to be delayed in the 6-gene group (p = .070), while thromboxane B2 (TXB2, a platelet activation marker) levels were lower over the first hour (p = .044) (401 ± 124 vs. 2048 ± 712 at 60 min). Thrombin production as measured by F1+2 levels tended to be lower in the 6-gene group (p = .058). CONCLUSIONS The combination of the hEPCR.hTBM.hCD47.hHO-1 cassette along with donor pig DDAVP and clodronate liposome pretreatment was associated with prolonged function of xenoperfused livers, reduced coagulation pathway perturbations, and decreased TXB2 elaboration, and reflects significant progress to modulate liver xenograft injury in a pig to human model.
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Affiliation(s)
- Arielle Cimeno
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | - Amy Dandro
- Revivicor, Inc., Blacksburg, Virginia, USA
| | - Selin Sendil
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Lars Burdorf
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Dawn M. Parsell
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | | | - Agnes M. Azimzadeh
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Richard N. Pierson
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Rolf N. Barth
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - John C. LaMattina
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
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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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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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7
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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: 5] [Impact Index Per Article: 1.7] [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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8
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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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9
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10
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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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11
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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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12
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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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13
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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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14
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Park HS, Kim JE, You HJ, Gu J, Yoo B, Lee S, Lee HJ, Hwang HY, Hwang Y, Kim HK, Kim YT. Beneficial effect of a nitric oxide donor in an ex vivo model of pig-to-human pulmonary xenotransplantation. Xenotransplantation 2016; 22:391-8. [PMID: 26381495 DOI: 10.1111/xen.12195] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 08/17/2015] [Indexed: 01/21/2023]
Abstract
BACKGROUND Nitric oxide (NO) can reduce platelet adhesion and vascular resistance. Tempol can scavenge the reactive oxygen species (ROS) that induce tissue injury. As xenograft rejection attenuates endogenous NO production and generates ROS, we evaluated the potential effect of an NO donor (SIN-1, 3-morpholinosydnonimine) and tempol on hyperacute xenograft dysfunction using an ex vivo porcine lung perfusion model. METHODS For the evaluation of von Willebrand factor (vWF) secretion, human endothelial cells were stimulated with thrombin. Porcine lungs were perfused with either fresh human whole blood (unmodified control group [n = 4]), SIN-1 (n = 4), or SIN and tempol (n = 4). RESULTS SIN-1 and tempol significantly inhibited vWF secretion from endothelial cells in vitro. However, they did not suppress xenogeneic complement activation. In an ex vivo pulmonary perfusion model, SIN-1 improved pulmonary xenograft function by reducing pulmonary vascular resistance (PVR), inhibiting complement activation, and inhibiting thrombin generation. Combined treatment with tempol and SIN-1 potentiated PVR reduction, but slightly enhanced complement activation. CONCLUSIONS An NO donor is expected to improve pulmonary xenograft function through inhibition of vWF secretion, vasoconstriction, thrombin generation, and indirectly through inhibition of complement activation. The additional effects of tempol on an NO donor were not considered significant in an ex vivo xenograft system.
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Affiliation(s)
- Hee Sue Park
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Ji-Eun Kim
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.,Xenotransplantation Research Center and Transplantation Research Institute, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Hyun Ju You
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.,Xenotransplantation Research Center and Transplantation Research Institute, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Jayoon Gu
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.,Xenotransplantation Research Center and Transplantation Research Institute, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Byungsu Yoo
- Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Saebom Lee
- Xenotransplantation Research Center and Transplantation Research Institute, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Hyun Joo Lee
- Xenotransplantation Research Center and Transplantation Research Institute, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.,Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Ho Young Hwang
- Xenotransplantation Research Center and Transplantation Research Institute, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.,Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Yoohwa Hwang
- Xenotransplantation Research Center and Transplantation Research Institute, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.,Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Hyun Kyung Kim
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.,Xenotransplantation Research Center and Transplantation Research Institute, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Young Tae Kim
- Xenotransplantation Research Center and Transplantation Research Institute, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.,Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Korea
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15
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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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16
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Kubicki N, Laird C, Burdorf L, Pierson RN, Azimzadeh AM. Current status of pig lung xenotransplantation. Int J Surg 2015; 23:247-254. [PMID: 26278663 DOI: 10.1016/j.ijsu.2015.08.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Revised: 07/27/2015] [Accepted: 08/04/2015] [Indexed: 12/15/2022]
Abstract
Human organ transplantation has improved duration and quality of life for many people, but its full potential is critically limited by short supply of available organs. One solution is xenotransplantation, although this comes with its own set of challenges. Lungs in particular are highly sensitive to injury, during the transplantation process generally, and to multiple immune rejection mechanisms. Using pig lung donors, our lab has been working on lung transplants into baboons as a surrogate for a human recipient. Several ex vivo human blood perfusion models have also proven useful. The combination of these experiments allows us to test large animal models as well as whole organ or isolated endothelial reactions to perfusion with human blood. We have found that a multi-modality therapeutic approach to prevent various pathogenic cascades - such as antibody-driven complement activation, other immune pathway activation, thrombosis, and tissue ischemia-reperfusion injury - has met with progressively greater success to protect the xeno lung from injury. Pig gene knockout and human gene transfer has been perhaps the greatest contributor. This review will discuss mechanisms of xeno lung injury, relevant experimental models, as well as recent results and future targets for research.
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Affiliation(s)
- Natalia Kubicki
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States.
| | - Christopher Laird
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - Lars Burdorf
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, and VA Maryland Health Care System, Baltimore, MD, United States
| | - Richard 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
| | - Agnes 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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17
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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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18
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Jin LD, Wang LR, Wu LQ, Shan YL, Zhao XY, Xiong XQ, Zhou JH, Lin LN, Jin LL. Effects of COX-2 inhibitor on ventilator-induced lung injury in rats. Int Immunopharmacol 2013; 16:288-95. [PMID: 23587488 DOI: 10.1016/j.intimp.2013.03.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 02/22/2013] [Accepted: 03/26/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND Mechanical ventilation especially with large tidal volume has been demonstrated to activate inflammatory response inducing lung injury, which could be attenuated by cyclooxygenase (COX)-2 inhibitors. As the main small integral membrane proteins that selectively conduct water molecules' transportation, aquaporin (AQP)-1 downregulation significantly related to lung edema and inflammation. This study aims to investigate the role of AQP1 in ventilator-induced lung injury in rats and evaluates the effects of COX-2 inhibition. METHODS Forty rats were allocated into four groups, where rats in Groups LD (low volume+DMSO) and LN (low volume+NS-398) were given intravenously 2ml DMSO and 8mg/kg NS-398 (a specific COX-2 inhibitor, dissolved in 2ml DMSO) before 4-hour lower tidal volume ventilation (8ml/kg), respectively, while DMSO and NS-398 were administrated in the same manner before 4-hour injurious ventilation (40ml/kg) in Groups HD (high volume+DMSO) and HN (high volume+NS-398). The arachidonic acid metabolites (6-keto prostaglandin F1α, thromboxane B2), inflammatory cytokines (tumor necrosis factor-α, interleukin-1β, 6, 8) and total protein levels in bronchoalveolar lavage (BAL) fluid and COX-2 mRNA and AQP1 protein expression in lung tissue were detected; water content and lung morphology were also evaluated. RESULTS Compared to Groups LD and LN, the rats in Groups HD and HN suffered obvious lung morphological changes with higher wet-to-dry weight ratio and lung injury score, and the levels of arachidonic acid metabolites, inflammatory cytokines and total protein in BAL fluid were increased, the expression of COX-2 mRNA was significantly upregulated and AQP1 protein was downregulated in lung tissue (p<0.05). The changes in BAL fluid and the severity of lung injury were attenuated, and AQP1 expression was upregulated in Group HN as compared to HD (p<0.05). CONCLUSIONS Ventilation with large tidal volume causes inflammatory mediator production and AQP1 downregulation, which could be attenuated by COX-2 inhibition.
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Affiliation(s)
- Li-da Jin
- Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical College, Wenzhou City, China
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19
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Cooper DKC, Ekser B, Burlak C, Ezzelarab M, Hara H, Paris L, Tector AJ, Phelps C, Azimzadeh AM, Ayares D, Robson SC, Pierson RN. Clinical lung xenotransplantation--what donor genetic modifications may be necessary? Xenotransplantation 2012; 19:144-58. [PMID: 22702466 PMCID: PMC3775598 DOI: 10.1111/j.1399-3089.2012.00708.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Barriers to successful lung xenotransplantation appear to be even greater than for other organs. This difficulty may be related to several macro anatomic factors, such as the uniquely fragile lung parenchyma and associated blood supply that results in heightened vulnerability of graft function to segmental or lobar airway flooding caused by loss of vascular integrity (also applicable to allotransplants). There are also micro-anatomic considerations, such as the presence of large numbers of resident inflammatory cells, such as pulmonary intravascular macrophages and natural killer (NK) T cells, and the high levels of von Willebrand factor (vWF) associated with the microvasculature. We have considered what developments would be necessary to allow successful clinical lung xenotransplantation. We suggest this will only be achieved by multiple genetic modifications of the organ-source pig, in particular to render the vasculature resistant to thrombosis. The major problems that require to be overcome are multiple and include (i) the innate immune response (antibody, complement, donor pulmonary and recipient macrophages, monocytes, neutrophils, and NK cells), (ii) the adaptive immune response (T and B cells), (iii) coagulation dysregulation, and (iv) an inflammatory response (e.g., TNF-α, IL-6, HMGB1, C-reactive protein). We propose that the genetic manipulation required to provide normal thromboregulation alone may include the introduction of genes for human thrombomodulin/endothelial protein C-receptor, and/or tissue factor pathway inhibitor, and/or CD39/CD73; the problem of pig vWF may also need to be addressed. It would appear that exploration of every available therapeutic path will be required if lung xenotransplantation is to be successful. To initiate a clinical trial of lung xenotransplantation, even as a bridge to allotransplantation (with a realistic possibility of survival long enough for a human lung allograft to be obtained), significant advances and much experimental work will be required. Nevertheless, with the steadily increasing developments in techniques of genetic engineering of pigs, we are optimistic that the goal of successful clinical lung xenotransplantation can be achieved within the foreseeable future. The optimistic view would be that if experimental pig lung xenotransplantation could be successfully managed, it is likely that clinical application of this and all other forms of xenotransplantation would become more feasible.
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Affiliation(s)
- David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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20
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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 are briefly reviewed and two different experimental models, the ex vivo porcine-to-human lung perfusion and the in vivo xenogeneic lung transplantation, are presented. We 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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Nguyen BNH, Azimzadeh AM, Schroeder C, Buddensick T, Zhang T, Laaris A, Cochrane M, Schuurman HJ, Sachs DH, Allan JS, Pierson RN. Absence of Gal epitope prolongs survival of swine lungs in an ex vivo model of hyperacute rejection. Xenotransplantation 2011; 18:94-107. [PMID: 21496117 DOI: 10.1111/j.1399-3089.2011.00633.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Galactosyl transferase gene knock-out (GalTKO) swine offer a unique tool to evaluate the role of the Gal antigen in xenogenic lung hyperacute rejection. METHODS We perfused GalTKO miniature swine lungs with human blood. Results were compared with those from previous studies using wild-type and human decay-accelerating factor-transgenic (hDAF(+/+) ) pig lungs. RESULTS GalTKO lungs survived 132 ± 52 min compared to 10 ± 9 min for wild-type lungs (P = 0.001) and 45 ± 60 min for hDAF(+/+) lungs (P = 0.18). GalTKO lungs displayed stable physiologic flow and pulmonary vascular resistance (PVR) until shortly before graft demise, similar to autologous perfusion, and unlike wild-type or hDAF(+/+) lungs. Early (15 and 60 min) complement (C3a) and platelet activation and intrapulmonary platelet deposition were significantly diminished in GalTKO lungs relative to wild-type or hDAF(+/+) lungs. However, GalTKO lungs adsorbed cytotoxic anti-non-Gal antibody and elaborated high levels of thrombin; their demise was associated with increased PVR, capillary congestion, intravascular thrombi and strong CD41 deposition not seen at earlier time points. CONCLUSIONS In summary, GalTKO lungs are substantially protected from injury but, in addition to anti-non-Gal antibody and complement, platelet adhesion and non-physiologic intravascular coagulation contribute to Gal-independent lung injury mechanisms.
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Affiliation(s)
- Bao-Ngoc H Nguyen
- Department of Surgery, University of Maryland and Baltimore VAMC, Baltimore, MD 21201, USA
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22
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O'Dea KP, Wilson MR, Dokpesi JO, Wakabayashi K, Tatton L, van Rooijen N, Takata M. Mobilization and margination of bone marrow Gr-1high monocytes during subclinical endotoxemia predisposes the lungs toward acute injury. THE JOURNAL OF IMMUNOLOGY 2009; 182:1155-66. [PMID: 19124759 DOI: 10.4049/jimmunol.182.2.1155] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The specialized role of mouse Gr-1(high) monocytes in local inflammatory reactions has been well documented, but the trafficking and responsiveness of this subset during systemic inflammation and their contribution to sepsis-related organ injury has not been investigated. Using flow cytometry, we studied monocyte subset margination to the pulmonary microcirculation during subclinical endotoxemia in mice and investigated whether marginated monocytes contribute to lung injury in response to further septic stimuli. Subclinical low-dose i.v. LPS induced a rapid (within 2 h), large-scale mobilization of bone marrow Gr-1high monocytes and their prolonged margination to the lungs. With secondary LPS challenge, membrane TNF expression on these premarginated monocytes substantially increased, indicating their functional priming in vivo. Zymosan challenge produced small increases in pulmonary vascular permeability, which were markedly enhanced by the preadministration of low-dose LPS. The LPS-zymosan-induced permeability increases were effectively abrogated by pretreatment (30 min before zymosan challenge) with the platelet-activating factor antagonist WEB 2086 in combination with the phosphatidylcholine-phospholipase C inhibitor D609, suggesting the involvement of platelet-activating factor/ceramide-mediated pathways in this model. Depletion of monocytes (at 18 h after clodronate-liposome treatment) significantly attenuated the LPS-zymosan-induced permeability increase. However, restoration of normal LPS-induced Gr-1high monocyte margination to the lungs (at 48 h after clodronate-liposome treatment) resulted in the loss of this protective effect. These results demonstrate that mobilization and margination of Gr-1high monocytes during subclinical endotoxemia primes the lungs toward further septic stimuli and suggest a central role for this monocyte subset in the development of sepsis-related acute lung injury.
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Affiliation(s)
- Kieran P O'Dea
- Department of Anaesthetics, Pain Medicine and Intensive Care, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, London, United Kingdom
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23
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Nguyen BNH, Azimzadeh AM, Zhang T, Wu G, Schuurman HJ, Shuurman HJ, Sachs DH, Ayares D, Allan JS, Pierson RN. Life-supporting function of genetically modified swine lungs in baboons. J Thorac Cardiovasc Surg 2007; 133:1354-63. [PMID: 17467457 DOI: 10.1016/j.jtcvs.2006.11.043] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 11/10/2006] [Accepted: 11/20/2006] [Indexed: 11/22/2022]
Abstract
OBJECTIVE During ex vivo perfusion with human blood, homozygous galactosyl transferase knockout swine lungs exhibit prolonged survival (approximately 2 hours) relative to wild-type (<15 minutes) and swine lungs expressing human decay accelerating factor (<1 hour). In this study, the in vivo behavior of galactosyl transferase knockout lungs was evaluated. METHODS Three galactosyl transferase knockout swine left lungs were transplanted into baboons in a life-supporting model. One baboon lung allograft and two swine lung xenografts transgenic for human membrane cofactor protein (CD46) served as controls. RESULTS Whereas two membrane cofactor protein lungs exhibited high pulmonary vascular resistance (>500 mm Hg x min/L) and failed to support life within 21 minutes, two of three galactosyl transferase knockout lungs supported life, for 90 and 215 minutes, and displayed low peripheral vascular resistance (48 +/- 12 mm Hg x min/L at 60 minutes), similar to the allogeneic control. Complement activation (delta C3a < 250 ng/mL through 60 minutes) and C5b-9 deposition were minimal in both galactosyl transferase knockout and membrane cofactor protein lungs. Neutrophils, monocytes, and platelets were rapidly sequestered in galactosyl transferase knockout and human membrane cofactor protein lung recipients, unlike the allogeneic control (<20%); and thrombin formation (delta plasma fraction 1+2 > 0.5 nmol/L) was seen in the galactosyl transferase knockout recipients. Platelet activation (beta-thromboglobulin rise > 200) and appearance of capillary congestion and vessel thrombosis confirmed coagulation activation associated with galactosyl transferase knockout lung failure. CONCLUSIONS Galactosyl transferase knockout swine lungs are significantly protected in vivo from the physiologic consequences (increased pulmonary vascular resistance, capillary leak) associated with hyperacute lung rejection. As during ex vivo perfusion, dysregulated coagulation-thrombin elaboration, platelet activation, and intravascular thrombosis-mediates galactosyl transferase knockout lung xenograft injury.
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Affiliation(s)
- Bao-Ngoc H Nguyen
- University of Maryland and Baltimore Veterans Administration Medical Center, Baltimore, USA
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24
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Cantu E, Balsara KR, Li B, Lau C, Gibson S, Wyse A, Baig K, Gaca J, Gonzalez-Stawinski GV, Nichols T, Parker W, Davis RD. Prolonged function of macrophage, von Willebrand factor-deficient porcine pulmonary xenografts. Am J Transplant 2007; 7:66-75. [PMID: 17109734 DOI: 10.1111/j.1600-6143.2006.01603.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Porcine von Willebrand factor (vWF) activates human and primate platelets. Having determined the importance of pulmonary intravascular macrophages (PIMs) in pulmonary xenotransplantation, we evaluated whether, in the absence of PIMs, vWF might play a role in pulmonary xenograft dysfunction. Utilizing a left single-lung transplant model, baboons depleted of anti-alphaGal antibodies received lungs from either vWF-deficient (n = 2); MCP-expressing (n = 5); MCP PIM-depleted (n = 5); or vWF-deficient PIM-depleted swine (n = 3). Two out of three of the PIM-depleted, pvWF deficient grafts survived longer than any previously reported pulmonary xenografts, including PIM-depleted xenografts expressing human complement regulatory proteins. Depletion of PIM's from vWF-deficient lungs, like depletion of PIM's from hMCP lungs, resulted in abrogation of the coagulopathy associated with pulmonary xenotransplantation. Thus, in terms of pulmonary graft survival, control of adverse reactions involving pvWF appears to be equally or even more important than is complement regulation using hMCP expression. However, based on the rapid failure of PIM-sufficient, pvWF-deficient pulmonary xenografts, pVWF-deficient pulmonary xenografts appear to be particularly sensitive to macrophage-mediated damage. These data provide initial evidence that vWF plays a role in the 'delayed' (24 h) dysfunction observed in pulmonary xenotransplantation using PIM depleted hMCP organs.
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Affiliation(s)
- E Cantu
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
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25
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Abstract
The lung is an anatomically complex vital organ whose normal physiology depends on actively regulated ventilation and perfusion, and maintenance of a delicate blood-air barrier over a huge surface area in direct contact with a potentially hostile environment. Despite significant progress over the past 25 years, both short- and long-term outcomes remain significantly inferior for lung recipients relative to other "solid" organs. This review summarizes the current status of lung transplantation so as to frame the principle challenges currently facing end-stage lung-failure patients and the practitioners who care for them.
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Affiliation(s)
- Richard N Pierson
- Division of Cardiac Surgery, Department of Surgery, University of Maryland and Baltimore VAMC, Baltimore, MD, USA.
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26
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Cantu E, Gaca JG, Palestrant D, Baig K, Lukes DJ, Gibson SE, Gonzalez-Stawinski GV, Olausson M, Parker W, Davis RD. Depletion of Pulmonary Intravascular Macrophages Prevents Hyperacute Pulmonary Xenograft Dysfunction. Transplantation 2006; 81:1157-64. [PMID: 16641602 DOI: 10.1097/01.tp.0000169758.57679.2a] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Recent years have brought dramatic progress in the field of xenotransplantation, with the development of transgenic swine and various other means of overcoming the rejection mediated by xenoreactive antibodies. Although progress has been rapid with kidney and heart xenografts, progress with pulmonary xenografts has lagged behind. Recent findings have suggested that donor pulmonary intravascular macrophages may play a critical role in the hyperacute dysfunction of pulmonary xenografts. METHODS The function of pulmonary xenografts from pigs depleted of pulmonary intravascular macrophages was compared with the function of xenografts from normal pigs. RESULTS Pulmonary xenografts from pigs from which pulmonary intravascular macrophages were depleted survived (23.5+/-0.9 hours) about five times longer than normal (macrophage sufficient) xenografts (4.4+/-1.41 hours) (P< 0.0001). At 21 hours post-reperfusion, the left pulmonary arterial flow was 225.0+/-34 ml/min in lungs depleted of pulmonary intravascular macrophages, whereas all normal xenografts had failed. CONCLUSIONS These findings indicate that donor macrophages play a critical role in pulmonary xenograft dysfunction. This finding has broad implications for xenotransplantation, suggesting that porcine macrophages might pose a barrier to the engraftment and function of a variety of porcine organ xenografts.
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Affiliation(s)
- Edward Cantu
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
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27
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Ghuysen A, Dogné JM, Chiap P, Rolin S, Masereel B, Lambermont B, Kolh P, Tchana-Sato V, Hanson J, D'Orio V. Pharmacological profile and therapeutic potential of BM-573, a combined thromboxane receptor antagonist and synthase inhibitor. ACTA ACUST UNITED AC 2005; 23:1-14. [PMID: 15867944 DOI: 10.1111/j.1527-3466.2005.tb00153.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BM-573 (N-terbutyl-N'-[2-(4'-methylphenylamino)-5-nitro-benzenesulfonyl]urea), a torsemide derivative, is a novel non-carboxylic dual TXA2 synthase inhibitor and receptor antagonist. The pharmacological profile of the drug is characterized by a higher affinity for the thromboxane receptor than that of SQ-29548, one of the most powerful antagonists described to date, by a complete prevention of human platelet aggregation induced by arachidonic acid at a lower dose than either torsemide or sulotroban, and by a significantly prolonged closure time measured by the platelet function analyser (PFA-100). Moreover, at the concentrations of 1 and 10 microM, BM-573 completely prevented production of TXB2 by human platelets activated by 0.6 mM of arachidonic acid. BM-573 prevents rat fundus contraction induced by U-46619 but not by prostacyclin or other prostaglandins. Despite possessing a chemical structure very similar to that of a diuretic torsemide, BM-573 has no diuretic activity. BM-573 does not prolong bleeding time and, unlike some of the other sulfonylureas, has no effect on blood glucose levels. In vivo, BM-573 appears to have antiplatelet and antithrombotic activities since it reduced thrombus weight and prolonged the time to abdominal aorta occlusion induced by ferric chloride. BM-573 also relaxed rat aorta and guinea pig trachea precontracted with U-46619. In pigs, BM-573 completely antagonized pulmonary hypertensive effects of U-46619 and reduced the early phase of pulmonary hypertension in models of endotoxic shock and pulmonary embolism. Finally, BM-573 protected pigs from myocardial infarction induced by coronary thrombosis. These results suggest that BM-573 should be viewed as a promising therapeutic agent in the treatment of pulmonary hypertension and syndromes associated with platelet activation.
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Affiliation(s)
- Alexandre Ghuysen
- Hemodynamics Research Laboratory (Hemoliège), University of Liège, Liège, Belgium.
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28
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Pfeiffer S, Zorn GL, Blair KSA, Farley SM, Wu G, Schuurman HJ, White DJG, Azimzadeh AM, Pierson RN. Hyperacute Lung Rejection in the Pig-to-Human Model 4: Evidence for Complement and Antibody Independent Mechanisms. Transplantation 2005; 79:662-71. [PMID: 15785372 DOI: 10.1097/01.tp.0000148922.32358.bf] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND We assessed whether the combination of complement regulation and depletion of xenoreactive antibodies improves the outcome of pulmonary xenografts compared with either strategy alone. METHODS Lungs from pigs heterozygous (hDAF(+/-)) or homozygous (hDAF(+/+)) for the human decay accelerating factor transgene (hDAF) or their nontransgenic litter mates (hDAF(-/-)) were perfused with heparinized whole human blood. In additional groups, xenoreactive natural antibodies (XNA) were depleted by pig lung perfusion (hDAF(-/-)/AbAbs, hDAF(+/-)/AbAbs) before the experiment. This combined approach was augmented by adding soluble complement receptor 1 (sCR1) to the perfusate in one further group (hDAF(+/-)/AbAbs/sCR1). RESULTS HDAF(-/-) lungs perfused with unmodified human blood were rejected after 32.5 min (interquartile range, IQR 5 to 210). HDAF(+/-) lungs survived for 90 min (IQR 10 to 161, P = 0.54). Both groups showed a rapid rise in pulmonary vascular resistance (PVR), which is a characteristic feature of hyperacute rejection (HAR). This phenomenon was blunted in the hDAF(+/+) group, although survival (48 min, IQR 14 to 111) was not further prolonged. Antibody depletion (AbAbs) led to a significant increase in survival time (hDAF(-/-)/AbAbs: 315 min, IQR 230 to 427; hDAF(+/-)/AbAbs: 375 min, IQR 154 to 575), reduced PVR and less complement production. Addition of sCR1 reduced complement elaboration but did not further improve survival (200 min, IQR 128 to 580) and surprisingly tended to increase PVR. CONCLUSIONS Depletion of xenoreactive antibodies is more effective than membrane-bound complement regulation to blunt hyperacute rejection of pulmonary xenografts, but even the combined approach including soluble-phase complement inhibition is not sufficient to reliably prevent organ failure within hours. It therefore seems likely that other factors independent of antibody and complement contribute to HAR in this model.
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Affiliation(s)
- Steffen Pfeiffer
- Department of Cardiac and Thoracic Surgery, Vanderbilt University Med-ical Center and VAMC, Nashville, Tennessee, USA
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29
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Schroeder C, Allan JS, Nguyen BN, Wu G, Zhang T, Azimzadeh AM, Madsen JC, Schuurman HJ, Sachs DH, Pierson RN. Hyperacute rejection is attenuated in GalT knockout swine lungs perfused ex vivo with human blood. Transplant Proc 2005; 37:512-3. [PMID: 15808693 DOI: 10.1016/j.transproceed.2004.12.133] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Hyperacute rejection (HAR) is one of the principal obstacles to successful xenotransplantation. Homozygous alpha-1,3-galactosyltransferase knockout (GalT-KO) miniature swine now offer the prospect of overcoming this barrier to xenotransplantation. In this study, the short-term function of GalT-KO swine lungs was evaluated in a well-established ex vivo model of swine-to-human lung xenotransplantation. METHODS Lungs from homozygous GalT-KO swine (n = 3) and control lungs from pigs of the background strain used to create the GalT-KO pig line (n = 2) were perfused ex vivo with freshly collected heparinized human blood. Graft function was assessed by various physiologic measurements, serial histologic and immunohistochemical evaluation, and assays of complement and platelet activation. RESULTS Xenoperfused control swine lungs exhibited HAR with graft survival times <5 minutes. In contrast, GalT-KO swine lungs retained their function for approximately 2 hours, on average. GalT-KO swine lungs showed decreased complement and platelet activation compared with controls. Nonetheless, activation of complement and coagulation cascades was not completely eliminated in the GalT-KO swine lungs. CONCLUSIONS The survival of xenoperfused GalT-KO swine lungs was significantly prolonged, as compared with control lungs expressing Gal. This appears to have been due largely to substantially reduced complement activation. Nonetheless, the xenoperfused GalT-KO lungs still showed some evidence of complement fixation and intravascular coagulopathy by the time of graft demise.
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Affiliation(s)
- C Schroeder
- Department of Surgery, Division of Thoracic Surgery, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts, USA
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30
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Abstract
Because organ transplantation is the preferred treatment for organ failure, the demand for human organs for transplantation is large and growing. From this demand, several fields based on new technologies for the replacement or repair of damaged tissues and organs have emerged. These fields include stem cell biology, cloning, tissue engineering and xenotransplantation. Here we evaluate the potential contribution of these to the devising of alternative approaches to organ replacement. We present our vision for the development of two structurally complex organs - the lung and the kidney - based on a 'fusion' of new and established technologies.
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Affiliation(s)
- Brenda Ogle
- Department of Physiology, Mayo Clinic, Rochester, MN, USA
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31
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Cantu E, Parker W, Platt JL, Duane Davis R. Pulmonary xenotransplantation: rapidly progressing into the unknown. Am J Transplant 2004; 4 Suppl 6:25-35. [PMID: 14871271 DOI: 10.1111/j.1600-6135.2004.0342.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
As one approach to circumventing the dire shortage of human lungs for transplantation, a handful of investigators have begun to probe the possibility of pulmonary xenotransplantation. The immunologic and perhaps physiologic barriers encountered by these investigators are considerable and progress in pulmonary xenotransplantation has lagged behind progress in cardiac and kidney xenotransplantation. However, during the last few years there have been substantial advances in the field of pulmonary xenotransplantation including, most noticeably, significant progress in attenuating hyperacute dysfunction. Progress has been made in understanding the barriers imposed by xenoreactive antibodies, complement, coagulation incompatibility and porcine pulmonary intravascular macrophages. Although our understanding of the barriers to pulmonary xenotransplantation is far from complete and the clinical application of pulmonary xenotransplantation is not yet in sight, current progress is fast paced. This progress provides a basis for future work and for a hope that the shortage of human lungs for transplantation will not always be a matter of life and death.
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Affiliation(s)
- Edward Cantu
- Department of Surgery, Duke University Medical Center, Durham, NC, USA.
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Singh B, Pearce JW, Gamage LN, Janardhan K, Caldwell S. Depletion of pulmonary intravascular macrophages inhibits acute lung inflammation. Am J Physiol Lung Cell Mol Physiol 2003; 286:L363-72. [PMID: 14565942 DOI: 10.1152/ajplung.00003.2003] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary intravascular macrophages (PIMs) are present in ruminants and horses. These species are highly sensitive to acute lung inflammation compared with non-PIM-containing species such as rats and humans. There is evidence that rats and humans may also recruit PIMs under certain conditions. We investigated precise contributions of PIMs to acute lung inflammation in a calf model. First, PIMs were recognized with a combination of in vivo phagocytic tracer Monastral blue and postembedding immunohistology with anti-CD68 monoclonal antibody. Second, gadolinium chloride depleted PIMs within 48 h of treatment (P < 0.05). Finally, PIMs contain TNF-alpha, and their depletion reduces cells positive for IL-8 (P < 0.05) and TNF-alpha (P < 0.05) and histopathological signs of acute lung inflammation in calves infected with Mannheimia hemolytica. The majority of IL-8-positive inflammatory cells in lung septa of infected calves were platelets. Platelets from normal cattle contained preformed IL-8 that was released upon in vitro exposure to thrombin (P < 0.05). These novel data show that PIMs, as the source of TNF-alpha, promote recruitment of inflammatory cells including IL-8-containing platelets to stimulate acute inflammation and pathology in lungs. These data may also be relevant to humans due to our ability to recruit PIMs.
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Affiliation(s)
- Baljit Singh
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada SK S7N 5B4.
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Abstract
The continued and growing success of lung allotransplantation has intensified the worldwide shortage of donor organs. Yet, xenotransplantation remains a daunting challenge. Additional molecular incompatibilities and unforeseen complications will continue to be discovered. Progress has been made, notably on the generation of alpha-Gal double knockout pigs. Progressive increases in organ survival times have been seen for most organs after significant investments of time and money. The lung continues to be an organ with the lowest supply of cadaveric donors and the least potential for expanded living donation or mechanical alternatives. As such, the impetus for xenotransplantation is strong. The lung appears to be exquisitely sensitive to xenograft rejection and resistant to strategies that have been moderately successful in other organs. A complex program involving genetically modified donor organs, recipient preparation for antibody removal or tolerance promotion, and multitargeted drug therapy will likely be required for successful clinical application.
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Affiliation(s)
- Thomas K Waddell
- Department of Surgery, Division of Thoracic Surgery, Toronto General Hospital, 200 Elizabeth Street, EN 10-233, Toronto, Ontario M5G 2C4, Canada.
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Beck-Speier I, Dayal N, Denzlinger C, Haberl C, Maier KL, Ziesenis A, Heyder J. Sulfur-related air pollutants induce the generation of platelet-activating factor, 5-lipoxygenase- and cyclooxygenase-products in canine alveolar macrophages via activation of phospholipases A2. Prostaglandins Other Lipid Mediat 2003; 71:217-34. [PMID: 14518563 DOI: 10.1016/s1098-8823(03)00041-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Recent studies have shown that long-term in vivo exposure of dogs to neutral sulfur(IV)/sulfite aerosols induces mild inflammatory reactions, whereas the combination of neutral sulfite with acidic sulfur(VI)/sulfate aerosols evokes less pronounced effects. To understand underlying mechanisms, we studied in vitro the role of lipid mediators in the responses of alveolar macrophages (AMs) to sulfur-related compounds under neutral (pH 7) or moderate acidic (pH 6) conditions. Canine AMs incubated with sulfite at pH 7 released threefold higher amounts of platelet-activating factor than control (P < 0.005). Generation of arachidonic acid, leukotriene B4, 5-hydroxy-eicosatetraenoic acid, prostaglandin E2, thromboxane B2 and 12-hydroxyheptadecatrienoic acid increased twofold (P < 0.0005). However, these metabolites remained unchanged following incubation of AMs with sulfite at pH 6 or with sulfate at pH 7 or pH 6. Mediator release by sulfite-treated AMs at pH 7 stimulated respiratory burst activity of neutrophils. Inhibition of MAPK pathway by PD 98059, of cytosolic (cPLA2) and secretory phospholipases A2 by AACOCF3 and thioetheramide-PC, respectively, reduced sulfite-induced eicosanoid formation in AMs. Sulfite activated cPLA2 activity twofold at pH 7. This mechanism of sulfite-stimulated responses in phospholipid metabolism predicts that chronic exposure to sulfur(IV)/sulfite is associated with a considerable health risk.
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Affiliation(s)
- Ingrid Beck-Speier
- GSF-National Research Center for Environment and Health, Institute for Inhalation Biology, D-85764 Neuherberg, Munich, Germany.
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35
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Gaca JG, Palestrant D, Lukes DJ, Olausson M, Parker W, Davis RD. Prevention of acute lung injury in swine: depletion of pulmonary intravascular macrophages using liposomal clodronate. J Surg Res 2003; 112:19-25. [PMID: 12873428 DOI: 10.1016/s0022-4804(03)00142-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Swine contain large numbers of pulmonary intravascular macrophages (PIMs) that mediate the physiological response observed in acute lung injury (ALI). As the hyperacute dysfunction observed in pulmonary xenotransplantation is similar to endotoxin-induced ALI, PIMs may play a critical role in pulmonary xenograft dysfunction. We used liposomal clodronate to eliminate the PIM population in a model of acute swine lung injury. MATERIALS AND METHODS Experimental swine (n = 6) received liposomal clodronate (1.25 g/10 kg) and control swine (n = 5) received saline containing liposomes before infusion of lipopolysaccharide (450 ng/kg). RESULTS Control swine demonstrated higher peak pulmonary artery pressures (41.8 +/- 2.2 versus 16.8 +/- 1.2 mm Hg; P < 0.0001) and higher peak pulmonary vascular resistances (1405 +/- 209 versus 353 +/- 81 dynes. s. cm(-5); P = 0.0016) in response to lipopolysaccharide infusion. Clodronate treated swine also had significantly lower serum levels of tumor necrosis factor-alpha, interleukin-6, and thrombin. CONCLUSIONS Liposomal clodronate effectively attenuates acute swine lung injury induced by endotoxin. This method of depletion of the PIM population presents a promising new treatment of swine lungs before xenotransplantation.
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Affiliation(s)
- Jeffrey G Gaca
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
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36
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Pfeiffer S, Zorn GL, Zhang JP, Giorgio TD, Robson SC, Azimzadeh AM, Pierson RN. Hyperacute lung rejection in the pig-to-human model. III. Platelet receptor inhibitors synergistically modulate complement activation and lung injury. Transplantation 2003; 75:953-9. [PMID: 12698079 DOI: 10.1097/01.tp.0000058517.07194.90] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The influence of platelet von Willebrand factor (vWF)-glycoprotein (GP)Ib-V-IX and GPIIb-IIIa receptor interactions in the context of hyperacute rejection (HAR) of pulmonary xenografts has not previously been explored. METHODS Aurintricarboxylic acid (ATA, an inhibitor of platelet-GPIb interactions with vWF), SC52012A (SC, a synthetic GPIIb/IIIa inhibiting peptide), or both were added to heparinized whole human blood before perfusion of isolated piglet lungs. Results were compared with unmodified blood ("unmodified"). RESULTS Perfusion of porcine lungs with unmodified human blood resulted in an immediate rise in pulmonary vascular resistance (PVR), fluid and platelet sequestration in the lung, and, without exception, cessation of function within 15 minutes with a mean survival of 8 minutes. Addition of ATA or SC before lung perfusion significantly decreased the rise in PVR, diminished histamine release, and prolonged survival to 31+/-11 and 31+/-22 minutes, respectively. When the therapies were combined, mean survival was 156+/-77 minutes (P<0.05 vs. either monotherapy). Complement activation was synergistically attenuated only when the drugs were used together. CONCLUSIONS Platelet protein receptor adhesive interactions play an important role in amplification of complement activation during hyperacute lung rejection. Inhibiting recruitment of platelets at the site of initial immunologic injury to endothelial cells may protect porcine organs against thrombosis and inflammation during the initial exposure to human blood.
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Affiliation(s)
- Steffen Pfeiffer
- Zentrum für Herzchirurgie Erlangen-Nürnberg, Klinikum Nürnberg Süd, 90471 Nuremberg, Germany
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Azimzadeh A, Zorn GL, Blair KSA, Zhang JP, Pfeiffer S, Harrison RA, Cozzi E, White DJG, Pierson RN. Hyperacute lung rejection in the pig-to-human model. 2. Synergy between soluble and membrane complement inhibition. Xenotransplantation 2003; 10:120-31. [PMID: 12588645 DOI: 10.1034/j.1399-3089.2003.01102.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND The role of complement in hyperacute lung xenograft rejection has not been elucidated. The present study evaluates the effect of complement (C) C3/C5 convertase inhibition on hyperacute rejection of pig lung by human blood. METHODS In an established ex-vivo model, lungs from pigs heterozygous for human decay accelerating factor (hDAF), non-transgenic littermate control pigs, or farm-bred pigs were perfused with fresh human blood that was either unmodified or treated with soluble complement receptor type 1 (sCR1: TP10, 100 microg/ml). RESULTS Non-transgenic lungs from littermate controls had a median survival time of 35 min (range 5 to 210; P = 0.25 vs. farm-bred piglets: median 5 min, range 5 to 10). Lungs expressing hDAF survived for a median of 90 min (range 10 to 161; P = 0.5 and 0.01 vs. littermate and farm-bred controls, respectively), with sCR1, whereas hDAF (-) lungs failed by 35 min (range 6 to 307), hDAF (+) lungs survived for 330 min (range 39 to 577) [P = 0.002 vs. farm-bred; P = 0.08 vs. hDAF (-); P = 0.17 vs. sCR1/hDAF (-)]. The rise in pulmonary vascular resistance (PVR) at 5 min was blunted only by hDAF (+) with sCR1 (0.26 +/- 0.2 vs. 0.5 to 0.7 mmHg/ml/min for other groups). Plasma C3a and sC5b-9 and tissue deposition of C5b-9 were dramatically diminished using sCR1, and further decreased in association with hDAF. Histamine and thromboxane were produced rapidly in all groups. CONCLUSION Complement plays an important role in lung HAR. However, even potent inhibition of C3/C5 convertase, both membrane bound in lung and by a soluble-phase inhibitor in the blood, does not prevent activation of inflammatory responses known to be particularly injurious to the lung. Our findings implicate a role for innate immune pathways resistant to efficient complement regulation. The role of anti-species antibody, coagulation pathway dysregulation, and additional environmental or genetic influences remain to be defined.
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Affiliation(s)
- A Azimzadeh
- Department of Cardiothoracic Surgery, The Vanderbilt Clinic, Vanderbilt University Medical Center, Nashville, TN 38232-5734, USA.
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Gaca JG, Lesher A, Aksoy O, Ruggeri ZM, Parker W, Davis RD. The role of the porcine von Willebrand factor: baboon platelet interactions in pulmonary xenotransplantation. Transplantation 2002; 74:1596-603. [PMID: 12490794 DOI: 10.1097/00007890-200212150-00018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Porcine von Willebrand factor (pvWF) has been shown to bind to human glycoprotein Ib (GPIb) and cause activation of human (or primate) platelets in the absence of shear stress. Pulmonary xenografts develop disseminated intravascular coagulation (DIC) and microvascular thrombosis within hours of reperfusion, and the aberrant interaction between pvWF and human platelets may be a possible cause of xenograft-associated DIC. METHODS Experimental baboons (n=3) received mouse anti-human GPIb monoclonal antibody before undergoing orthotopic pulmonary xenotransplantation with porcine lungs expressing human membrane cofactor protein (CD46). RESULTS Blocking the pvWF-GPIb interaction with a monoclonal antibody to GPIb prevented the agglutination of human and baboon platelets by pvWF in vitro. In vivo, the anti-GPIb antibody prevented platelet deposition and prevented the increases in D-Dimers (P=0.011) seen in control xenograft recipients (n=5). However, there was no difference in elevations of prothrombin times (PT) or improvement in the vasoconstriction associated with the loss of xenograft function. CONCLUSIONS This study indicates that the DIC associated with the hyperacute dysfunction of pulmonary xenografts is a complex phenomenon that is affected by, but not solely dependent on, activation of platelets. Aberrant interactions between pvWF and GPIb play a significant role in DIC associated with pulmonary xenotransplantation.
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Affiliation(s)
- Jeffrey G Gaca
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
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Pfeiffer S, Zorn GL, Kelishadi S, Oriol R, Wolf P, Pierson RN, Azimzadeh AM. Role of anti-Gal alpha13Gal and anti-platelet antibodies in hyperacute rejection of pig lung by human blood. Ann Thorac Surg 2001; 72:1681-9; discussion 1690. [PMID: 11722065 DOI: 10.1016/s0003-4975(01)03033-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND Previous work has shown that antibodies against porcine antigens are an important trigger of hyperacute lung rejection (HALR). The relative importance of Gal alpha1,3Gal epitopes and other antigens, such as those expressed on pig platelet membranes or lung itself, has not been defined. This study compares the efficiency of three anti-pig antibody depletion strategies, and their efficacy with regard to attenuation of HALR. METHODS Plasma pooled from three human donors was adsorbed against Gal alpha1,3Gal disaccharide or porcine platelet extract (PPE), or passed through pig lung vasculature. Whole blood reconstituted using adsorbed plasma was then used to perfuse piglet lung, and results were compared with unmodified human blood. RESULTS Depletion of lung-reactive anti-Gal alpha1-3Gal antibodies was most efficient with the alphaGal column (99% +/- 0.5% vs 87% to 93% +/- 11% for PPE and 92% to 95% +/- 8% for lung, p < 0.01 vs alphaGal column). PPE column tended to be more efficient (77% to 84% +/- 12%) in removing anti-PPE antibodies than pig lung (66% to 70% +/- 14%) or the alphaGal column (56% to 63% +/- 16%, p < 0.05). Lung survival and function with each antibody depletion strategy was improved relative to unmodified controls (mean survival > or = 146 minutes vs 8 minutes for controls). Although alphaGal and lung adsorption yielded more consistent lung protection (survival beyond 2 hours) than did PPE, no approach proved significantly superior. Complement C3a elaboration at 10 minutes was attenuated > 80% by each adsorption strategy, an effect that was most pronounced in the lung adsorption group (95%, p < 0.01). Histamine elaboration was blunted significantly by PPE adsorption but not in other groups (p < 0.05). Platelet but not leukocyte sequestration was decreased with antibody depletion compared with the nondepleted group (44% to 50% vs 82%, p < 0.01). CONCLUSIONS Each antibody depletion strategy tested significantly prolongs lung xenograft survival and function compared with unmodified human blood, but none was sufficient to reliably prevent HALR. Depletion of antibodies against both alphaGal and additional cell membrane antigens, or control of antibody-independent pathogenic pathways, may be necessary to consistently prevent HALR.
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Affiliation(s)
- S Pfeiffer
- Department of Cardiac and Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232-5734, USA
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