1
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Byrne GW, McGregor CGA. Anti-pig antibodies in swine veterinarian serum: Implications for clinical xenotransplantation. Xenotransplantation 2024; 31:e12865. [PMID: 38853364 DOI: 10.1111/xen.12865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/06/2024] [Accepted: 05/14/2024] [Indexed: 06/11/2024]
Abstract
Recent clinical xenotransplantation and human decedent studies demonstrate that clinical hyperacute rejection of genetically engineered porcine organs can be reliably avoided but that antibody mediated rejection (AMR) continues to limit graft survival. We previously identified porcine glycans and proteins which are immunogenic after cardiac xenotransplantation in non-human primates, but the clinical immune response to antigens present in glycan depleted triple knockout (TKO) donor pigs is poorly understood. In this study we use fluorescence barcoded human embryonic kidney cells (HEK) and HEK cell lines expressing porcine glycans (Gal and SDa) or proteins (tetraspanin-29 [CD9], membrane cofactor protein [CD46], protectin, membrane attack complex inhibition factor [CD59], endothelial cell protein C receptor, and Annexin A2) to screen antibody reactivity in human serum from 160 swine veterinarians, a serum source with potential occupational immune challenge from porcine tissues and pathogens. High levels of anti-Gal IgM were present in all samples and lower levels of anti-SDa IgM were present in 41% of samples. IgM binding to porcine proteins, primarily CD9 and CD46, previously identified as immunogenic in pig to non-human primate cardiac xenograft recipients, was detected in 28 of the 160 swine veterinarian samples. These results suggest that barcoded HEK cell lines expressing porcine protein antigens can be useful for screening human patient serum. A comprehensive analysis of sera from clinical xenotransplant recipients to define a panel of commonly immunogenic porcine antigens will likely be necessary to establish an array of porcine non-Gal antigens for effective monitoring of patient immune responses and allow earlier therapies to reverse AMR.
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Affiliation(s)
- Guerard W Byrne
- Twin Cities, Department of Surgery, Experimental Surgical Services, University of Minnesota, Minneapolis, Minnesota, USA
- Institute of Cardiovascular Sciences, University College London, London, UK
| | - Christopher G A McGregor
- Twin Cities, Department of Surgery, Experimental Surgical Services, University of Minnesota, Minneapolis, Minnesota, USA
- Institute of Cardiovascular Sciences, University College London, London, UK
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2
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Lee JS, Mitulović G, Panahipour L, Gruber R. Proteomic Analysis of Porcine-Derived Collagen Membrane and Matrix. MATERIALS 2020; 13:ma13225187. [PMID: 33212864 PMCID: PMC7698422 DOI: 10.3390/ma13225187] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/06/2020] [Accepted: 11/11/2020] [Indexed: 12/13/2022]
Abstract
Collagen membranes and matrices being widely used in guided bone regeneration and soft tissue augmentation have characteristic properties based on their composition. The respective proteomic signatures have not been identified. Here, we performed a high-resolution shotgun proteomic analysis on two porcine collagen-based biomaterials designed for guided bone regeneration and soft tissue augmentation. Three lots each of a porcine-derived collagen membrane and a matrix derived from peritoneum and/or skin were digested and separated by nano-reverse-phase high-performance liquid chromatography. The peptides were subjected to mass spectrometric detection and analysis. A total of 37 proteins identified by two peptides were present in all collagen membranes and matrices, with 11 and 16 proteins being exclusively present in the membrane and matrix, respectively. The common extracellular matrix proteins include fibrillar collagens (COL1A1, COL1A2, COL2A1, COL3A1, COL5A1, COL5A2, COL5A3, COL11A2), non-fibrillar collagens (COL4A2, COL6A1, COL6A2, COL6A3, COL7A1, COL16A1, COL22A1), and leucine-rich repeat proteoglycans (DCN, LUM, BGN, PRELP, OGN). The structural proteins vimentin, actin-based microfilaments (ACTB), annexins (ANXA1, ANXA5), tubulins (TUBA1B, TUBB), and histones (H2A, H2B, H4) were also identified. Examples of membrane-only proteins are COL12A1 and COL14A1, and, of matrix only proteins, elastin (ELN). The proteomic signature thus revealed the similarities between but also some individual proteins of collagen membrane and matrix.
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Affiliation(s)
- Jung-Seok Lee
- Department of Oral Biology, School of Dentistry, Medical University of Vienna, 1090 Vienna, Austria; (J.-S.L.); (L.P.)
- Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul 03722, Korea
| | - Goran Mitulović
- Proteomics Core Facility, Clinical Institute of Laboratory Medicine, Medical University of Vienna, 1090 Vienna, Austria;
| | - Layla Panahipour
- Department of Oral Biology, School of Dentistry, Medical University of Vienna, 1090 Vienna, Austria; (J.-S.L.); (L.P.)
| | - Reinhard Gruber
- Department of Oral Biology, School of Dentistry, Medical University of Vienna, 1090 Vienna, Austria; (J.-S.L.); (L.P.)
- Proteomics Core Facility, Clinical Institute of Laboratory Medicine, Medical University of Vienna, 1090 Vienna, Austria;
- Department of Periodontology, School of Dental Medicine, University of Bern, 3010 Bern, Switzerland
- Correspondence:
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3
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Burlak C, Taylor RT, Wang ZY, Tector AJ. Human anti‐α‐fucose antibodies are xenoreactive toward GGTA1/CMAH knockout pigs. Xenotransplantation 2020; 27:e12629. [DOI: 10.1111/xen.12629] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/28/2020] [Accepted: 06/22/2020] [Indexed: 11/29/2022]
Affiliation(s)
| | - R. Travis Taylor
- Department of Medical Microbiology and Immunology University of Toledo Medical Center Toledo OH USA
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4
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HLA Class I-sensitized Renal Transplant Patients Have Antibody Binding to SLA Class I Epitopes. Transplantation 2020; 103:1620-1629. [PMID: 30951017 DOI: 10.1097/tp.0000000000002739] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Highly sensitized patients are difficult to match with suitable renal allograft donors and may benefit from xenotransplant trials. We evaluate antibody binding from sensitized patients to pig cells and engineered single allele cells to identify anti-human leukocyte antigen (HLA) antibody cross-species reactivity with swine leukocyte antigen (SLA). These novel testing strategies assess HLA/SLA epitopes and antibody-binding patterns and introduce genetic engineering of SLA epitopes. METHODS Sensitized patient sera were grouped by calculated panel reactive antibody and luminex single antigen reactivity profile and were tested with cloned GGTA1/CMAH/B4GalNT2 glycan knockout porcine cells. Pig reactivity was assessed by direct flow cytometric crossmatch and studied following elution from pig cells. To study the antigenicity of individual class I HLA and SLA alleles in cells, irrelevant sera binding to lymphoblastoid cells were minimized by CRISPR/Cas9 elimination of endogenous class I and class II HLA, B-cell receptor, and Fc receptor genes. Native HLA, SLA, and mutants of these proteins after mutating 144K to Q were assessed for antibody binding. RESULTS Those with predominately anti-HLA-B&C antibodies, including Bw6 and Bw4 sensitization, frequently have low pig reactivity. Conversely, antibodies eluted from porcine cells are more commonly anti-HLA-A. Single HLA/SLA expressing engineered cells shows variable antigenicity and mutation of 144K to Q reduces antibody binding for some sensitized patients. CONCLUSIONS Anti-HLA antibodies cross-react with SLA class I in predictable patterns, which can be identified with histocompatibility strategies, and SLA class I is a possible target of genetic engineering.
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5
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Kim SC, Mathews DV, Breeden CP, Higginbotham LB, Ladowski J, Martens G, Stephenson A, Farris AB, Strobert EA, Jenkins J, Walters EM, Larsen CP, Tector M, Tector AJ, Adams AB. Long-term survival of pig-to-rhesus macaque renal xenografts is dependent on CD4 T cell depletion. Am J Transplant 2019; 19:2174-2185. [PMID: 30821922 PMCID: PMC6658347 DOI: 10.1111/ajt.15329] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 01/22/2019] [Accepted: 02/04/2019] [Indexed: 01/25/2023]
Abstract
The shortage of available organs remains the greatest barrier to expanding access to transplant. Despite advances in genetic editing and immunosuppression, survival in experimental models of kidney xenotransplant has generally been limited to <100 days. We found that pretransplant selection of recipients with low titers of anti-pig antibodies significantly improved survival in a pig-to-rhesus macaque kidney transplant model (6 days vs median survival time 235 days). Immunosuppression included transient pan-T cell depletion and an anti-CD154-based maintenance regimen. Selective depletion of CD4+ T cells but not CD8+ T cells resulted in long-term survival (median survival time >400 days vs 6 days). These studies suggested that CD4+ T cells may have a more prominent role in xenograft rejection compared with CD8+ T cells. Although animals that received selective depletion of CD8+ T cells showed signs of early cellular rejection (marked CD4+ infiltrates), animals receiving selective CD4+ depletion exhibited normal biopsy results until late, when signs of chronic antibody rejection were present. In vitro study results suggested that rhesus CD4+ T cells required the presence of SLA class II to mount an effective proliferative response. The combination of low pretransplant anti-pig antibody and CD4 depletion resulted in consistent, long-term xenograft survival.
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Affiliation(s)
- SC Kim
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, Georgia
| | - DV Mathews
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, Georgia
| | - CP Breeden
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, Georgia
| | - LB Higginbotham
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, Georgia
| | - J Ladowski
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri
| | - G Martens
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri
| | - A Stephenson
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, Georgia
| | - AB Farris
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, Georgia
| | - EA Strobert
- Yerkes National Primate Research Center, School of Medicine, Emory University, Atlanta, Georgia
| | - J Jenkins
- Yerkes National Primate Research Center, School of Medicine, Emory University, Atlanta, Georgia
| | - EM Walters
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri
| | - CP Larsen
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, Georgia,Yerkes National Primate Research Center, School of Medicine, Emory University, Atlanta, Georgia
| | - M Tector
- Comprehensive Transplant Institute, University of Alabama Birmingham School of Medicine, Birmingham, Alabama
| | - AJ Tector
- Comprehensive Transplant Institute, University of Alabama Birmingham School of Medicine, Birmingham, Alabama
| | - AB Adams
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, Georgia,Yerkes National Primate Research Center, School of Medicine, Emory University, Atlanta, Georgia
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6
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Zhou H, Hara H, Cooper DK. The complex functioning of the complement system in xenotransplantation. Xenotransplantation 2019; 26:e12517. [PMID: 31033064 PMCID: PMC6717021 DOI: 10.1111/xen.12517] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 03/15/2019] [Accepted: 03/22/2019] [Indexed: 12/25/2022]
Abstract
The role of complement in xenotransplantation is well-known and is a topic that has been reviewed previously. However, our understanding of the immense complexity of its interaction with other constituents of the innate immune response and of the coagulation, adaptive immune, and inflammatory responses to a xenograft is steadily increasing. In addition, the complement system plays a function in metabolism and homeostasis. New reviews at intervals are therefore clearly warranted. The pathways of complement activation, the function of the complement system, and the interaction between complement and coagulation, inflammation, and the adaptive immune system in relation to xenotransplantation are reviewed. Through several different mechanisms, complement activation is a major factor in contributing to xenograft failure. In the organ-source pig, the detrimental influence of the complement system is seen during organ harvest and preservation, for example, in ischemia-reperfusion injury. In the recipient, the effect of complement can be seen through its interaction with the immune, coagulation, and inflammatory responses. Genetic-engineering and other therapeutic methods by which the xenograft can be protected from the effects of complement activation are discussed. The review provides an updated source of reference to this increasingly complex subject.
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Affiliation(s)
- Hongmin Zhou
- Department of Cardiothoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David K.C. Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
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7
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Li KYC. Bioprosthetic Heart Valves: Upgrading a 50-Year Old Technology. Front Cardiovasc Med 2019; 6:47. [PMID: 31032263 PMCID: PMC6470412 DOI: 10.3389/fcvm.2019.00047] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/26/2019] [Indexed: 01/09/2023] Open
Abstract
Prosthetic heart valves have been commonly used to address the increasing prevalence of valvular heart disease. The ideal prosthetic heart valve substitute should closely mimic the characteristics of a normal native heart valve. Despite the development of various interventions, an exemplary valve replacement does not exist. This review provides an overview of the novel engineering valve designs and explores emergent immunologic insights into age-dependent structural valve degeneration (SVD).
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Affiliation(s)
- Kan Yan Chloe Li
- Institute of Cardiovascular Science, University College London, London, United Kingdom
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8
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Peloso A, Citro A, Zoro T, Cobianchi L, Kahler-Quesada A, Bianchi CM, Andres A, Berishvili E, Piemonti L, Berney T, Toso C, Oldani G. Regenerative Medicine and Diabetes: Targeting the Extracellular Matrix Beyond the Stem Cell Approach and Encapsulation Technology. Front Endocrinol (Lausanne) 2018; 9:445. [PMID: 30233489 PMCID: PMC6127205 DOI: 10.3389/fendo.2018.00445] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 07/18/2018] [Indexed: 12/20/2022] Open
Abstract
According to the Juvenile Diabetes Research Foundation (JDRF), almost 1. 25 million people in the United States (US) have type 1 diabetes, which makes them dependent on insulin injections. Nationwide, type 2 diabetes rates have nearly doubled in the past 20 years resulting in more than 29 million American adults with diabetes and another 86 million in a pre-diabetic state. The International Diabetes Ferderation (IDF) has estimated that there will be almost 650 million adult diabetic patients worldwide at the end of the next 20 years (excluding patients over the age of 80). At this time, pancreas transplantation is the only available cure for selected patients, but it is offered only to a small percentage of them due to organ shortage and the risks linked to immunosuppressive regimes. Currently, exogenous insulin therapy is still considered to be the gold standard when managing diabetes, though stem cell biology is recognized as one of the most promising strategies for restoring endocrine pancreatic function. However, many issues remain to be solved, and there are currently no recognized treatments for diabetes based on stem cells. In addition to stem cell resesarch, several β-cell substitutive therapies have been explored in the recent era, including the use of acellular extracellular matrix scaffolding as a template for cellular seeding, thus providing an empty template to be repopulated with β-cells. Although this bioengineering approach still has to overcome important hurdles in regards to clinical application (including the origin of insulin producing cells as well as immune-related limitations), it could theoretically provide an inexhaustible source of bio-engineered pancreases.
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Affiliation(s)
- Andrea Peloso
- Division of Abdominal Surgery, Department of Surgery, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- HepatoPancreato-Biliary Centre, Geneva University Hospitals, Geneva, Switzerland
| | - Antonio Citro
- San Raffaele Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Tamara Zoro
- Department of General Surgery, IRCCS Policlinico San Matteo, Pavia, Italy
- Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, University of Pavia, Pavia, Italy
| | - Lorenzo Cobianchi
- Department of General Surgery, IRCCS Policlinico San Matteo, Pavia, Italy
- Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, University of Pavia, Pavia, Italy
| | - Arianna Kahler-Quesada
- Division of Abdominal Surgery, Department of Surgery, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Carlo M. Bianchi
- Department of General Surgery, IRCCS Policlinico San Matteo, Pavia, Italy
- Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, University of Pavia, Pavia, Italy
| | - Axel Andres
- Division of Abdominal Surgery, Department of Surgery, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- HepatoPancreato-Biliary Centre, Geneva University Hospitals, Geneva, Switzerland
| | - Ekaterine Berishvili
- Cell Isolation and Transplantation Center, University of Geneva, Geneva, Switzerland
- Institute of Medical Research, Ilia State University, Tbilisi, Georgia
| | - Lorenzo Piemonti
- San Raffaele Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Thierry Berney
- Cell Isolation and Transplantation Center, University of Geneva, Geneva, Switzerland
| | - Christian Toso
- Division of Abdominal Surgery, Department of Surgery, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- HepatoPancreato-Biliary Centre, Geneva University Hospitals, Geneva, Switzerland
| | - Graziano Oldani
- Division of Abdominal Surgery, Department of Surgery, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- HepatoPancreato-Biliary Centre, Geneva University Hospitals, Geneva, Switzerland
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9
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Byrne G, Ahmad-Villiers S, Du Z, McGregor C. B4GALNT2 and xenotransplantation: A newly appreciated xenogeneic antigen. Xenotransplantation 2018; 25:e12394. [PMID: 29604134 PMCID: PMC6158069 DOI: 10.1111/xen.12394] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 03/08/2018] [Accepted: 03/13/2018] [Indexed: 12/20/2022]
Abstract
Analysis of non‐Gal antibody induced after pig‐to‐baboon cardiac xenotransplantation identified the glycan produced by porcine beta‐1,4‐N‐acetyl‐galactosaminyltransferase 2 (B4GALNT2) as an immunogenic xenotransplantation antigen. The porcine B4GALNT2 enzyme is homologous to the human enzyme, which synthesizes the human SDa blood group antigen. Most humans produce low levels of anti‐SDa IgM which polyagglutinates red blood cells from rare individuals with high levels of SDa expression. The SDa glycan is also present on GM2 gangliosides. Clinical GM2 vaccination studies for melanoma patients suggest that a human antibody response to SDa can be induced. Expression of porcine B4GALNT2 in human HEK293 cells results in increased binding of anti‐SDa antibody and increased binding of Dolichos biflorus agglutinin (DBA), a lectin commonly used to detect SDa. In pigs, B4GALNT2 is expressed by vascular endothelial cells and endothelial cells from a wide variety of pig backgrounds stain with DBA, suggesting that porcine vascular expression of B4GALNT2 is not polymorphic. Mutations in B4GALNT2 have been engineered in mice and pigs. In both species, the B4GALNT2‐KO animals are apparently normal and no longer show evidence of SDa antigen expression. Pig tissues with a mutation in B4GALNT2, added to a background of alpha‐1,3‐galactosyltransferase deficient (GGTA1‐KO) and cytidine monophosphate‐N‐acetylneuraminic acid hydroxylase deficient (CMAH‐KO), show reduced antibody binding, confirming the presence of B4GALNT2‐dependent antibodies in both humans and non‐human primates. Preclinical xenotransplantation using B4GALNT2‐deficient donors has recently been reported. Elimination of this source of immunogenic pig antigen should minimize acute injury by preformed anti‐pig antibody and eliminate an induced clinical immune response to this newly appreciated xenotransplantation antigen.
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Affiliation(s)
- Guerard Byrne
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Surgery, Mayo Clinic, Rochester, MN, USA
| | | | - Zeji Du
- Department of Surgery, Mayo Clinic, Rochester, MN, USA
| | - Christopher McGregor
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Surgery, Mayo Clinic, Rochester, MN, USA
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10
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Hurh S, Kang B, Choi I, Cho B, Lee EM, Kim H, Kim YJ, Chung YS, Jeong JC, Hwang JI, Kim JY, Lee BC, Surh CD, Yang J, Ahn C. Human antibody reactivity against xenogeneic N-glycolylneuraminic acid and galactose-α-1,3-galactose antigen. Xenotransplantation 2016; 23:279-92. [PMID: 27373998 DOI: 10.1111/xen.12239] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/07/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND Despite the development of α1,3-galactosyl transferase-knockout (GTKO) pigs, acute humoral xenograft rejection caused by antibodies against non-Gal antigens, along with complement activation, are hurdles that need to be overcome. Among non-Gal antigens, N-glycolylneuraminic acid (Neu5Gc) is considered to play an important role in xenograft rejection in human. METHODS We generated human embryonic kidney 293 (HEK293) cells that expressed xenogeneic Neu5Gc (HEK293-pCMAH) or α1,3Gal (HEK293-pGT) antigen and investigated the degree of human antibody binding and complement-dependent cytotoxicity (CDC) against these antigens using 100 individual human sera. RESULTS Both IgM and IgG bound to α1,3Gal, while only IgG bound to Neu5Gc. Of the ABO blood groups, the degree of IgG binding to α1,3Gal was highest for blood group A. The degree of CDC against HEK293-pCMAH cells was significantly lower than that against HEK293-pGT cells. However, CDC against HEK293-pCMAH cells was significantly higher than that against control HEK293 cells. In addition, the severity of CDC against HEK293-pCMAH cells positively correlated with that against GTKO pig aortic endothelial cells (PAECs), suggesting that Neu5Gc is the main antigen in GTKO PAECs. Similar to antibody-binding activity, only IgG binding correlated with CDC against HEK293-pCMAH cells. The most common subclass of IgGs against Neu5Gc was IgG1, which typically induces strong complement activation. CONCLUSIONS We showed that IgG-mediated CDC was detected in Neu5Gc-overexpressed HEK293 cells incubated with human sera; however, this antibody reactivity to Neu5Gc was highly variable among individuals. Our results suggest that additional modifications to the CMAH gene should be considered for widespread use of pig organs for human transplants.
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Affiliation(s)
- Sunghoon Hurh
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Korea.,Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Bohae Kang
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Korea.,Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Inho Choi
- Department of Pharmaceutical Engineering, College of Life and Health Sciences, Hoseo University, Asan, Chungcheongnam-do, Korea
| | - Bumrae Cho
- Designed Animal & Transplantation Research Institute, Institute of Green Bio Science & Technology, Seoul National University, Pyeongchang, Gangwon-do, Korea
| | - Eun Mi Lee
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Korea.,Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Hwajung Kim
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Young June Kim
- Designed Animal & Transplantation Research Institute, Institute of Green Bio Science & Technology, Seoul National University, Pyeongchang, Gangwon-do, Korea
| | - Yun Shin Chung
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Jong Cheol Jeong
- Department of Nephrology, Ajou University School of Medicine, Suwon, Gyeonggi-do, Korea
| | - Jong-Ik Hwang
- Graduate School of Medicine, Korea University, Seoul, Korea
| | - Jae Young Kim
- Department of Life Science, Gachon University, Seongnam, Korea
| | - Byeong Chun Lee
- Designed Animal & Transplantation Research Institute, Institute of Green Bio Science & Technology, Seoul National University, Pyeongchang, Gangwon-do, Korea.,Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, Korea.,Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Charles D Surh
- Academy of Immunology and Microbiology, Institute for Basic Science, Pohang, Korea.,Department of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, Korea.,Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA
| | - Jaeseok Yang
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Korea.,Transplantation Center, Seoul National University Hospital, Seoul, Korea
| | - Curie Ahn
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Korea.,Designed Animal & Transplantation Research Institute, Institute of Green Bio Science & Technology, Seoul National University, Pyeongchang, Gangwon-do, Korea.,Transplantation Center, Seoul National University Hospital, Seoul, Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
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11
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Abstract
The availability of cells, tissues and organs from a non-human species such as the pig could, at least in theory, meet the demand of organs necessary for clinical transplantation. At this stage, the important goal of getting over the first year of survival has been reported for both cellular and solid organ xenotransplantation in relevant preclinical primate models. In addition, xenotransplantation is already in the clinic as shown by the broad use of animal-derived medical devices, such as bioprosthetic heart valves and biological materials used for surgical tissue repair. At this stage, however, prior to starting a wide-scale clinical application of xenotransplantation of viable cells and organs, the important obstacle represented by the humoral immune response will need to be overcome. Likewise, the barriers posed by the activation of the innate immune system and coagulative pathway will have to be controlled. As far as xenogeneic nonviable xenografts, increasing evidence suggests that considerable immune reactions, mediated by both innate and adaptive immunity, take place and influence the long-term outcome of xenogeneic materials in patients, possibly precluding the use of bioprosthetic heart valves in young individuals. In this context, the present article provides an overview of current knowledge on the immune processes following xenotransplantation and on the possible therapeutic interventions to overcome the immunological drawbacks involved in xenotransplantation.
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Affiliation(s)
- M Vadori
- CORIT (Consortium for Research in Organ Transplantation), Via dell'Università 10, 35020 Legnaro, Padua, Italy
| | - E Cozzi
- CORIT (Consortium for Research in Organ Transplantation), Via dell'Università 10, 35020 Legnaro, Padua, Italy.,Transplant Immunology Unit, Department of Transfusion Medicine, Padua University Hospital, Via Giustiniani, 2, 35128 Padua, Italy
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12
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Wiles K, Fishman JM, De Coppi P, Birchall MA. The Host Immune Response to Tissue-Engineered Organs: Current Problems and Future Directions. TISSUE ENGINEERING PART B-REVIEWS 2016; 22:208-19. [DOI: 10.1089/ten.teb.2015.0376] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
| | | | | | - Martin A. Birchall
- UCL Ear Institute & Royal National Throat, Nose and Ear Hospital, London, United Kingdom
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13
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Lin Y, Miyagi N, Byrne GW, Du Z, Kogelberg H, Gazi MH, Tazelaar HD, Wang C, McGregor CGA. A pig-to-mouse coronary artery transplantation model for investigating the pathogenicity of anti-pig antibody. Xenotransplantation 2015; 22:458-67. [PMID: 26490445 PMCID: PMC10022689 DOI: 10.1111/xen.12198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/25/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND Rejection of Gal-free (GTKO) donor pig cardiac xenografts is strongly associated with vascular non-Gal antibody binding, endothelial cell (EC) injury, and activation and microvascular thrombosis. We adopted a pig-to-SCID/beige small animal transplant model to compare the pathogenicity of baboon and human anti-pig antibody. METHODS Wild-type (GT(+) ) or GTKO porcine coronary arteries (PCAs) were transplanted into the infrarenal aorta of SCID/beige mice. Three days after transplant, recipients were infused with anti-pig antibody (anti-SLA class I, an isotype control, naive or sensitized baboon serum, or naive human serum). PCAs were recovered 24 h after antibody infusion and examined using histology, immunohistochemistry, and in situ hybridization. RESULTS Dose-dependent intragraft thrombosis occurred after infusion of anti-SLA I antibody (but not isotype control) in GT(+) and GTKO PCA recipients. Naive baboon serum induced thrombosis in GT(+) grafts. Thrombosis was significantly reduced by pre-treating naive baboon serum with Gal polymer and not observed when this serum was infused to GTKO PCA recipients. Naive human serum caused dose-dependent intragraft thrombosis of GTKO PCAs. In all cases, thrombosis involved graft-specific vascular antibody and complement deposition, macrophage adherence, EC delamination, and subendothelial thrombus formation. CONCLUSIONS This study provides the first direct in vivo comparison of the pathogenicity of naive human and baboon serum. The results suggest that human preformed non-Gal antibody may have increased pathogenicity compared to baboon. This model, which showed a rejected graft histopathology similar to antibody-mediated rejection in cardiac xenotransplantation, may be useful to assess the pathogenicity of individual protein or carbohydrate specific non-Gal reactive antibodies.
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Affiliation(s)
- Yi Lin
- Department of Surgery, Mayo Clinic, Rochester, MN, USA.,Department of Cardiovascular Surgery, Zhongshan Hospital of Fudan University, Shanghai, China
| | - Naoto Miyagi
- Department of Surgery, Mayo Clinic, Rochester, MN, USA
| | - Guerard W Byrne
- Department of Surgery, Mayo Clinic, Rochester, MN, USA.,Institute of Cardiovascular Science, University College London, London, UK
| | - Zeji Du
- Department of Surgery, Mayo Clinic, Rochester, MN, USA
| | - Heide Kogelberg
- Institute of Cardiovascular Science, University College London, London, UK
| | | | - Henry D Tazelaar
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, AZ, USA
| | - Chunsheng Wang
- Department of Cardiovascular Surgery, Zhongshan Hospital of Fudan University, Shanghai, China
| | - Christopher G A McGregor
- Department of Surgery, Mayo Clinic, Rochester, MN, USA.,Institute of Cardiovascular Science, University College London, London, UK
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Byrne GW, McGregor CGA, Breimer ME. Recent investigations into pig antigen and anti-pig antibody expression. Int J Surg 2015; 23:223-228. [PMID: 26306769 DOI: 10.1016/j.ijsu.2015.07.724] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 07/22/2015] [Accepted: 07/26/2015] [Indexed: 01/17/2023]
Abstract
Genetic engineering of donor pigs to eliminate expression of the dominant xenogeneic antigen galactose α1,3 galactose (Gal) has created a sea change in the immunobiology of xenograft rejection. Antibody mediated xenograft rejection of GGTA-1 α-galactosyltransferase (GTKO) deficient organs is now directed to a combination of non-Gal pig protein and carbohydrate antigens. Glycan analysis of GTKO tissues identified no new neo-antigens but detected high levels of N-acetylneuraminic acid (Neu5Gc) modified glycoproteins and glycolipids. Humans produce anti-Neu5Gc antibody and in very limited clinical studies sometimes show an induced anti-Neu5Gc antibody response after challenge with pig tissue. The pathogenicity of anti-Neu5Gc antibody in xenotransplantation is not clear however as non-human transplant models, critical for modelling anti-Gal immunity, do not produce anti-Neu5Gc antibody. Antibody induced after xenotransplantation in non-human primates is directed to an array of pig endothelial cells proteins and to a glycan produced by the pig B4GALNT2 gene. We anticipate that immune suppression will significantly affect the T-cell dependent and independent specificity of an induced antibody response and that donor pigs deficient in synthesis of multiple xenogeneic glycans will be important to future studies.
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Affiliation(s)
- Guerard W Byrne
- Department of Surgery, Mayo Clinic, Rochester, MN 55905, USA; Institute of Cardiovascular Science, University College London, London WC1E 6JF, UK.
| | - Christopher G A McGregor
- Department of Surgery, Mayo Clinic, Rochester, MN 55905, USA; Institute of Cardiovascular Science, University College London, London WC1E 6JF, UK
| | - Michael E Breimer
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden
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15
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Higginbotham L, Mathews D, Breeden CA, Song M, Farris AB, Larsen CP, Ford ML, Lutz AJ, Tector M, Newell KA, Tector AJ, Adams AB. Pre-transplant antibody screening and anti-CD154 costimulation blockade promote long-term xenograft survival in a pig-to-primate kidney transplant model. Xenotransplantation 2015; 22:221-30. [PMID: 25847130 DOI: 10.1111/xen.12166] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 02/08/2015] [Indexed: 12/13/2022]
Abstract
Xenotransplantation has the potential to alleviate the organ shortage that prevents many patients with end-stage renal disease from enjoying the benefits of kidney transplantation. Despite significant advances in other models, pig-to-primate kidney xenotransplantation has met limited success. Preformed anti-pig antibodies are an important component of the xenogeneic immune response. To address this, we screened a cohort of 34 rhesus macaques for anti-pig antibody levels. We then selected animals with both low and high titers of anti-pig antibodies to proceed with kidney transplant from galactose-α1,3-galactose knockout/CD55 transgenic pig donors. All animals received T-cell depletion followed by maintenance therapy with costimulation blockade (either anti-CD154 mAb or belatacept), mycophenolate mofetil, and steroid. The animal with the high titer of anti-pig antibody rejected the kidney xenograft within the first week. Low-titer animals treated with anti-CD154 antibody, but not belatacept exhibited prolonged kidney xenograft survival (>133 and >126 vs. 14 and 21 days, respectively). Long-term surviving animals treated with the anti-CD154-based regimen continue to have normal kidney function and preserved renal architecture without evidence of rejection on biopsies sampled at day 100. This description of the longest reported survival of pig-to-non-human primate kidney xenotransplantation, now >125 days, provides promise for further study and potential clinical translation.
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Affiliation(s)
- Laura Higginbotham
- Department of Surgery, Emory Transplant Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Dave Mathews
- Department of Surgery, Emory Transplant Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Cynthia A Breeden
- Department of Surgery, Emory Transplant Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Mingqing Song
- Department of Surgery, Emory Transplant Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Alton Brad Farris
- Anatomic Pathology, Emory University School of Medicine, Atlanta, GA, USA
| | - Christian P Larsen
- Department of Surgery, Emory Transplant Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Mandy L Ford
- Department of Surgery, Emory Transplant Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Andrew J Lutz
- Department of Surgery, Indiana University Health Transplant Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Matthew Tector
- Indiana University Health Transplant Department, Indianapolis, IN, USA
| | - Kenneth A Newell
- Department of Surgery, Emory Transplant Center, Emory University School of Medicine, Atlanta, GA, USA
| | - A Joseph Tector
- Department of Surgery, Indiana University Health Transplant Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Andrew B Adams
- Department of Surgery, Emory Transplant Center, Emory University School of Medicine, Atlanta, GA, USA
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16
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Griesemer A, Yamada K, Sykes M. Xenotransplantation: immunological hurdles and progress toward tolerance. Immunol Rev 2015; 258:241-58. [PMID: 24517437 DOI: 10.1111/imr.12152] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The discrepancy between organ need and organ availability represents one of the major limitations in the field of transplantation. One possible solution to this problem is xenotransplantation. Research in this field has identified several obstacles that have so far prevented the successful development of clinical xenotransplantation protocols. The main immunologic barriers include strong T-cell and B-cell responses to solid organ and cellular xenografts. In addition, components of the innate immune system can mediate xenograft rejection. Here, we review these immunologic and physiologic barriers and describe some of the strategies that we and others have developed to overcome them. We also describe the development of two strategies to induce tolerance across the xenogeneic barrier, namely thymus transplantation and mixed chimerism, from their inception in rodent models through their current progress in preclinical large animal models. We believe that the addition of further beneficial transgenes to Gal knockout swine, combined with new therapies such as Treg administration, will allow for successful clinical application of xenotransplantation.
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Affiliation(s)
- Adam Griesemer
- Columbia Center for Translational Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA
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17
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Bassols A, Costa C, Eckersall PD, Osada J, Sabrià J, Tibau J. The pig as an animal model for human pathologies: A proteomics perspective. Proteomics Clin Appl 2014; 8:715-31. [DOI: 10.1002/prca.201300099] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 04/28/2014] [Accepted: 07/30/2014] [Indexed: 12/15/2022]
Affiliation(s)
- Anna Bassols
- Departament de Bioquímica i Biologia Molecular; Facultat de Veterinària; Universitat Autònoma de Barcelona; Cerdanyola del Vallès Spain
| | - Cristina Costa
- New Therapies of Genes and Transplants Group; Institut d'Investigació Biomèdica de Bellvitge (IDIBELL); L'Hospitalet de Llobregat; Barcelona Spain
| | - P. David Eckersall
- Institute of Biodiversity, Animal Health and Comparative Medicine; University of Glasgow; Glasgow UK
| | - Jesús Osada
- Departamento de Bioquímica y Biología Molecular; Facultad de Ciencias; Universidad de Zaragoza; CIBEROBN; Zaragoza Spain
| | - Josefa Sabrià
- Departament de Bioquímica i Biologia Molecular; Facultat de Medicina; Institut de Neurociències (INc); Universitat Autònoma de Barcelona; Cerdanyola del Vallès Spain
| | - Joan Tibau
- IRTA - Food Technology; Animal Genetics Program; Finca Camps i Armet; Monells Spain
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18
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Burlak C, Taylor RT. Xenotransplantation literature update, July-August 2014. Xenotransplantation 2014; 21:482-4. [PMID: 25250866 DOI: 10.1111/xen.12144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 09/04/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher Burlak
- Department of Surgery, Schultz Diabetes Institute, University of Minnesota, Minneapolis, MN, USA
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19
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Azimzadeh AM, Byrne GW, Ezzelarab M, Welty E, Braileanu G, Cheng X, Robson SC, McGregor CGA, Cooper DKC, Pierson RN. Development of a consensus protocol to quantify primate anti-non-Gal xenoreactive antibodies using pig aortic endothelial cells. Xenotransplantation 2014; 21:555-66. [PMID: 25176173 DOI: 10.1111/xen.12125] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 05/30/2014] [Indexed: 01/05/2023]
Abstract
BACKGROUND Scientists working in the field of xenotransplantation do not employ a uniform method to measure and report natural and induced antibody responses to non-Galα(1,3)Gal (non-Gal) epitopes. Such humoral responses are thought to be particularly pathogenic after transplantation of vascularized GalTKO pig organs and having a more uniform assay and reporting format would greatly facilitate comparisons between laboratories. METHODS Flow cytometry allows examination of antibody reactivity to intact antigens in their natural location and conformation on cell membranes. We have established a simple and reproducible flow cytometric assay to detect antibodies specific for non-Gal pig antigens using primary porcine aortic endothelial cells (pAECs) and cell culture-adapted pAEC cell lines generated from wild type and α1,3galactosyl transferase knockout (GalTKO) swine. RESULTS The consensus protocol we propose here is based on procedures routinely used in four xenotransplantation centers and was independently evaluated at three sites using shared cells and serum samples. Our observation support use of the cell culture-adapted GalTKO pAEC KO:15502 cells as a routine method to determine the reactivity of anti-non-Gal antibodies in human and baboon serum. CONCLUSIONS We have developed an assay that allows the detection of natural and induced non-Gal xenoreactive antibodies present in human or baboon serum in a reliable and consistent manner. This consensus assay and format for reporting the data should be accessible to laboratories and will be useful for assessing experimental results between multiple research centers. Adopting this assay and format for reporting the data should facilitate the detection, monitoring, and detailed characterization of non-Gal antibody responses.
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Affiliation(s)
- Agnes M Azimzadeh
- Division of Cardiac Surgery, University of Maryland and VAMC Baltimore, Baltimore, MD, USA
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20
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Burlak C, Paris L, Lutz A, Sidner R, Estrada J, Li P, Tector M, Tector A. Reduced binding of human antibodies to cells from GGTA1/CMAH KO pigs. Am J Transplant 2014; 14:1895-900. [PMID: 24909344 PMCID: PMC4366649 DOI: 10.1111/ajt.12744] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 03/07/2014] [Accepted: 03/12/2014] [Indexed: 01/25/2023]
Abstract
Xenotransplantation using genetically modified pig organs could solve the donor organ shortage problem. Two inactivated genes that make humans unique from pigs are GGTA1 and CMAH, the products of which produce the carbohydrate epitopes, aGal and Neu5Gc that attract preformed human antibody. When the GGTA1 and CMAH genes were deleted in pigs, human antibody binding was reduced in preliminary analysis. We analyzed the binding of human IgM and IgG from 121 healthy human serum samples for binding to GGTA1 KO and GGTA1/CMAH KO peripheral blood mononuclear cells (PBMCs). We analyzed a sub population for reactivity toward genetically modified pig PBMCs as compared to chimpanzee and human PBMCs. Deletion of the GGTA1 and CMAH genes in pigs improved the crossmatch results beyond those observed with chimpanzees. Sorting the 121 human samples tested against the GGTA1/CMAH KO pig PBMCs did not reveal a distinguishing feature such as blood group, age or gender. Modification of genes to make pig carbohydrates more similar to humans has improved the crossmatch with human serum significantly.
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Affiliation(s)
- C. Burlak
- Indiana University School of Medicine, Department of Surgery, Indianapolis, Indiana
| | - L.L. Paris
- Indiana University School of Medicine, Department of Surgery, Indianapolis, Indiana
| | - A.J. Lutz
- Indiana University School of Medicine, Department of Surgery, Indianapolis, Indiana
| | - R.A. Sidner
- Indiana University School of Medicine, Department of Surgery, Indianapolis, Indiana
| | - J. Estrada
- Indiana University School of Medicine, Department of Surgery, Indianapolis, Indiana
| | - P. Li
- Indiana University School of Medicine, Department of Surgery, Indianapolis, Indiana
| | - M. Tector
- Indiana University Health Transplant Institute, Indianapolis, Indiana
| | - A.J. Tector
- Indiana University Health Transplant Institute, Indianapolis, Indiana
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21
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Wang ZY, Burlak C, Estrada JL, Li P, Tector MF, Tector AJ. Erythrocytes from GGTA1/CMAH knockout pigs: implications for xenotransfusion and testing in non-human primates. Xenotransplantation 2014; 21:376-84. [PMID: 24986655 DOI: 10.1111/xen.12106] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 04/07/2014] [Indexed: 11/27/2022]
Abstract
BACKGROUND Pig erythrocytes are potentially useful to solve the worldwide shortage of human blood for transfusion. Domestic pig erythrocytes, however, express antigens that are bound by human preformed antibodies. Advances in genetic engineering have made it possible to rapidly knock out the genes of multiple xenoantigens, namely galactose α1,3 galactose (aGal) and N-glycolylneuraminic acid (Neu5Gc). We have recently targeted the GGTA1 and CMAH genes with zinc finger endonucleases resulting in double knockout pigs that no longer express aGal or Neu5Gc and attract significantly fewer human antibodies. In this study, we characterized erythrocytes from domestic and genetically modified pigs, baboons, chimpanzees, and humans for binding of human and baboon natural antibody, and complement-mediated lysis. METHODS Distribution of anti-Neu5Gc IgG and IgM in pooled human AB serum was analyzed by ELISA. Erythrocytes from domestic pigs (Dom), aGal knockout pigs (GGTA1 KO), aGal and Neu5Gc double knockout pigs (GGTA1/CMAH KO), baboons, chimpanzees, and humans were analyzed by flow cytometry for aGal and Neu5Gc expression. In vitro comparative analysis of erythrocytes was conducted with pooled human AB serum and baboon serum. Total antibody binding was accessed by hemagglutination; complement-dependent lysis was measured by hemolytic assay; IgG or IgM binding to erythrocytes was characterized by flow cytometry. RESULTS The pooled human AB serum contained 0.38 μg/ml anti-Neu5Gc IgG and 0.085 μg/ml anti-Neu5Gc IgM. Both Gal and Neu5Gc were not detectable on GGTA1/CMAH KO erythrocytes. Hemagglutination of GGTA1/CMAH KO erythrocytes with human serum was 3.5-fold lower compared with GGTA1 KO erythrocytes, but 1.6-fold greater when agglutinated with baboon serum. Hemolysis of GGTA1/CMAH KO erythrocytes by human serum (25%) was reduced 9-fold compared with GGTA1 KO erythrocytes, but increased 1.64-fold by baboon serum. Human IgG binding was reduced 27-fold on GGTA1/CMAH KO erythrocytes compared with GGTA1 KO erythrocytes, but markedly increased 3-fold by baboon serum IgG. Human IgM binding was decreased 227-fold on GGTA1/CMAH KO erythrocytes compared with GGTA1 KO erythrocytes, but enhanced 5-fold by baboon serum IgM. CONCLUSIONS Removal of aGal and Neu5Gc antigens from pig erythrocytes significantly reduced human preformed antibody-mediated cytotoxicity but may have complicated future in vivo analysis by enhancing reactivity from baboons. The creation of the GGTA1/CMAH KO pig has provided the xenotransplantation researcher with organs and cells that attract fewer human antibodies than baboon and our closest primate relative, chimpanzee. These finding suggest that while GGTA1/CMAH KO erythrocytes may be useful for human transfusions, in vivo testing in the baboon may not provide a direct transplantation to the clinic.
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Affiliation(s)
- Zheng-Yu Wang
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
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22
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Vadori M, Cozzi E. Immunological challenges and therapies in xenotransplantation. Cold Spring Harb Perspect Med 2014; 4:a015578. [PMID: 24616201 DOI: 10.1101/cshperspect.a015578] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Xenotransplantation, or the transplantation of cells, tissues, or organs between different species, was proposed a long time ago as a possible solution to the worldwide shortage of human organs and tissues for transplantation. In this setting, the pig is currently seen as the most likely candidate species. In the last decade, progress in this field has been remarkable and includes a better insight into the immunological mechanisms underlying the rejection process. Several immunological hurdles nonetheless remain, such as the strong antibody-mediated and innate or adaptive cellular immune responses linked to coagulation derangements, precluding indefinite xenograft survival. This article reviews our current understanding of the immunological mechanisms involved in xenograft rejection and the potential strategies that may enable xenotransplantation to become a clinical reality in the not-too-distant future.
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Affiliation(s)
- Marta Vadori
- CORIT (Consortium for Research in Organ Transplantation), Legnaro, 35020 Padua, Italy
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23
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Cowan PJ, Cooper DKC, d'Apice AJF. Kidney xenotransplantation. Kidney Int 2014; 85:265-75. [PMID: 24088952 PMCID: PMC3946635 DOI: 10.1038/ki.2013.381] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 07/12/2013] [Accepted: 07/17/2013] [Indexed: 12/14/2022]
Abstract
Xenotransplantation using pigs as donors offers the possibility of eliminating the chronic shortage of donor kidneys, but there are several obstacles to be overcome before this goal can be achieved. Preclinical studies have shown that, while porcine renal xenografts are broadly compatible physiologically, they provoke a complex rejection process involving preformed and elicited antibodies, heightened innate immune cell reactivity, dysregulated coagulation, and a strong T cell-mediated adaptive response. Furthermore, the susceptibility of the xenograft to proinflammatory and procoagulant stimuli is probably increased by cross-species molecular defects in regulatory pathways. To balance these disadvantages, xenotransplantation has at its disposal a unique tool to address particular rejection mechanisms and incompatibilities: genetic modification of the donor. This review focuses on the pathophysiology of porcine renal xenograft rejection, and on the significant genetic, pharmacological, and technical progress that has been made to prolong xenograft survival.
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Affiliation(s)
- Peter J Cowan
- 1] Immunology Research Centre, St Vincent's Hospital, Melbourne, Victoria, Australia [2] Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Anthony J F d'Apice
- 1] Immunology Research Centre, St Vincent's Hospital, Melbourne, Victoria, Australia [2] Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
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Byrne GW, Azimzadeh AM, Ezzelarab M, Tazelaar HD, Ekser B, Pierson RN, Robson SC, Cooper DKC, McGregor CGA. Histopathologic insights into the mechanism of anti-non-Gal antibody-mediated pig cardiac xenograft rejection. Xenotransplantation 2013; 20:292-307. [PMID: 25098626 PMCID: PMC4126170 DOI: 10.1111/xen.12050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/31/2013] [Indexed: 01/13/2023]
Abstract
The histopathology of cardiac xenograft rejection has evolved over the last 20 yr with the development of new modalities for limiting antibody-mediated injury, advancing regimens for immune suppression, and an ever-widening variety of new donor genetics. These new technologies have helped us progress from what was once an overwhelming anti-Gal-mediated hyperacute rejection to a more protracted anti-Gal-mediated vascular rejection to what is now a more complex manifestation of non-Gal humoral rejection and coagulation dysregulation. This review summarizes the changing histopathology of Gal- and non-Gal-mediated cardiac xenograft rejection and discusses the contributions of immune-mediated injury, species-specific immune-independent factors, transplant and therapeutic procedures, and donor genetics to the overall mechanism(s) of cardiac xenograft rejection.
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Affiliation(s)
- Guerard W Byrne
- Institute of Cardiovascular Science, University College London, London, UK; Department of Surgery, Mayo Clinic, Rochester, MN, USA
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25
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Chihara RK, Lutz AJ, Paris LL, Wang ZY, Sidner RA, Heyrman AT, Downey SM, Burlak C, Tector AJ. Fibronectin from alpha 1,3-galactosyltransferase knockout pigs is a xenoantigen. J Surg Res 2013; 184:1123-33. [PMID: 23673165 DOI: 10.1016/j.jss.2013.04.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/21/2013] [Accepted: 04/05/2013] [Indexed: 01/05/2023]
Abstract
BACKGROUND Antibody-mediated rejection continues to be an obstacle for xenotransplantation despite development of α1,3-galactosyltransferase knockout (GTKO) pigs. Fibronectin (Fn) from GTKO pigs was identified as a xenoantigen in baboons. N-glycolylneuraminic acid (Neu5Gc), similar to galactose α1,3-galactose, is an antigenic carbohydrate found in pigs. We evaluated human antibody reactivity and performed initial antigenic epitope characterization of Fn from GTKO pigs. MATERIALS AND METHODS GTKO pig aortic endothelial cells (AEC) were isolated and assessed for antibody-mediated complement-dependent cytotoxicity (CDC). Human and GTKO pig Fn were purified and analyzed using immunoblots. GTKO pig and human AEC absorbed human sera were assessed for CDC and anti-GTKO pig Fn antibodies. GTKO pig proteins were assessed for Neu5Gc. Immunoaffinity-purified human IgG anti-GTKO pig (hIgG-GTKOp) Fn using a GTKO pig Fn column were evaluated for cross-reactivity with other proteins. RESULTS GTKO pig AEC had greater human antibody binding, complement deposition and CDC compared with allogeneic human AEC. Human sera absorbed with GTKO pig AEC resulted in diminished anti-GTKO pig Fn antibody. Neu5Gc was identified on GTKO pig Fn and other proteins. The hIgG-GTKOp Fn cross-reacted with multiple GTKO pig proteins and was enriched with anti-Neu5Gc antibody. CONCLUSIONS Removal of antigenic epitopes from GTKO pig AEC would improve xenograft compatibility. GTKO pig Fn has antigenic epitopes, one identified as Neu5Gc, which may be responsible for pathology and cross-reactivity of hIgG-GTKOp Fn. Genetic knockout of Neu5Gc appears necessary to address significance and identification of non-Neu5Gc GTKO pig Fn antigenic epitopes.
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Affiliation(s)
- Ray K Chihara
- Indiana University School of Medicine, Indianapolis, Indiana
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26
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Ekser B, Burlak C, Waldman JP, Lutz AJ, Paris LL, Veroux M, Robson SC, Rees MA, Ayares D, Gridelli B, Tector AJ, Cooper DKC. Immunobiology of liver xenotransplantation. Expert Rev Clin Immunol 2012; 8:621-34. [PMID: 23078060 PMCID: PMC3774271 DOI: 10.1586/eci.12.56] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Pigs are currently the preferred species for future organ xenotransplantation. With advances in the development of genetically modified pigs, clinical xenotransplantation is becoming closer to reality. In preclinical studies (pig-to-nonhuman primate), the xenotransplantation of livers from pigs transgenic for human CD55 or from α1,3-galactosyltransferase gene-knockout pigs+/- transgenic for human CD46, is associated with survival of approximately 7-9 days. Although hepatic function, including coagulation, has proved to be satisfactory, the immediate development of thrombocytopenia is very limiting for pig liver xenotransplantation even as a 'bridge' to allotransplantation. Current studies are directed to understand the immunobiology of platelet activation, aggregation and phagocytosis, in particular the interaction between platelets and liver sinusoidal endothelial cells, hepatocytes and Kupffer cells, toward identifying interventions that may enable clinical application.
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Affiliation(s)
- Burcin Ekser
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
- Department of Surgery, Transplant Institute, Indiana University School of Medicine, Indiana University Health, Indianapolis, IN, USA
- Department of Surgery, Transplantation and Advanced Technologies, Vascular Surgery and Organ Transplant Unit, University Hospital of Catania, Catania, Italy
| | - Christopher Burlak
- Department of Surgery, Transplant Institute, Indiana University School of Medicine, Indiana University Health, Indianapolis, IN, USA
| | - Joshua P Waldman
- Department of Urology, University of Toledo Health Sciences Campus, Toledo, OH, USA
| | - Andrew J Lutz
- Department of Surgery, Transplant Institute, Indiana University School of Medicine, Indiana University Health, Indianapolis, IN, USA
| | - Leela L Paris
- Department of Surgery, Transplant Institute, Indiana University School of Medicine, Indiana University Health, Indianapolis, IN, USA
| | - Massimiliano Veroux
- Department of Surgery, Transplantation and Advanced Technologies, Vascular Surgery and Organ Transplant Unit, University Hospital of Catania, Catania, Italy
| | - Simon C Robson
- Liver Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Michael A Rees
- Department of Urology, University of Toledo Health Sciences Campus, Toledo, OH, USA
| | | | - Bruno Gridelli
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
- Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo, Italy
| | - A Joseph Tector
- Department of Surgery, Transplant Institute, Indiana University School of Medicine, Indiana University Health, Indianapolis, IN, USA
| | - David KC Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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Wang ZY, Paris LL, Chihara RK, Tector AJ, Burlak C. Immortalized porcine liver sinusoidal endothelial cells: an in vitro model of xenotransplantation-induced thrombocytopenia. Xenotransplantation 2012; 19:249-55. [DOI: 10.1111/j.1399-3089.2012.00715.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Schneider MKJ, Seebach JD. Xenotransplantation literature update, March to April 2012. Xenotransplantation 2012; 19:207-11. [PMID: 22702472 DOI: 10.1111/j.1399-3089.2012.00707.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mårten K J Schneider
- Division of Internal Medicine, University Hospital Zurich Service of Immunology and Allergology, Department of Internal Medicine, University Hospital and Medical Faculty, Geneva, Switzerland.
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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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