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Längin M, Reichart B, Steen S, Sjöberg T, Paskevicius A, Liao Q, Qin G, Mokelke M, Mayr T, Radan J, Issl L, Buttgereit I, Ying J, Fresch AK, Panelli A, Egerer S, Bähr A, Kessler B, Milusev A, Sfriso R, Rieben R, Ayares D, Murray PJ, Ellgass R, Walz C, Klymiuk N, Wolf E, Abicht JM, Brenner P. Cold non-ischemic heart preservation with continuous perfusion prevents early graft failure in orthotopic pig-to-baboon xenotransplantation. Xenotransplantation 2020; 28:e12636. [PMID: 32841431 DOI: 10.1111/xen.12636] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/22/2020] [Accepted: 07/30/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND Successful preclinical transplantations of porcine hearts into baboon recipients are required before commencing clinical trials. Despite years of research, over half of the orthotopic cardiac xenografts were lost during the first 48 hours after transplantation, primarily caused by perioperative cardiac xenograft dysfunction (PCXD). To decrease the rate of PCXD, we adopted a preservation technique of cold non-ischemic perfusion for our ongoing pig-to-baboon cardiac xenotransplantation project. METHODS Fourteen orthotopic cardiac xenotransplantation experiments were carried out with genetically modified juvenile pigs (GGTA1- KO/hCD46/hTBM) as donors and captive-bred baboons as recipients. Organ preservation was compared according to the two techniques applied: cold static ischemic cardioplegia (IC; n = 5) and cold non-ischemic continuous perfusion (CP; n = 9) with an oxygenated albumin-containing hyperoncotic cardioplegic solution containing nutrients, erythrocytes and hormones. Prior to surgery, we measured serum levels of preformed anti-non-Gal-antibodies. During surgery, hemodynamic parameters were monitored with transpulmonary thermodilution. Central venous blood gas analyses were taken at regular intervals to estimate oxygen extraction, as well as lactate production. After surgery, we measured troponine T and serum parameters of the recipient's kidney, liver and coagulation functions. RESULTS In porcine grafts preserved with IC, we found significantly depressed systolic cardiac function after transplantation which did not recover despite increasing inotropic support. Postoperative oxygen extraction and lactate production were significantly increased. Troponin T, creatinine, aspartate aminotransferase levels were pathologically high, whereas prothrombin ratios were abnormally low. In three of five IC experiments, PCXD developed within 24 hours. By contrast, all nine hearts preserved with CP retained fully preserved systolic function, none showed any signs of PCXD. Oxygen extraction was within normal ranges; serum lactate as well as parameters of organ functions were only mildly elevated. Preformed anti-non-Gal-antibodies were similar in recipients receiving grafts from either IC or CP preservation. CONCLUSIONS While standard ischemic cardioplegia solutions have been used with great success in human allotransplantation over many years, our data indicate that they are insufficient for preservation of porcine hearts transplanted into baboons: Ischemic storage caused severe impairment of cardiac function and decreased tissue oxygen supply, leading to multi-organ failure in more than half of the xenotransplantation experiments. In contrast, cold non-ischemic heart preservation with continuous perfusion reliably prevented early graft failure. Consistent survival in the perioperative phase is a prerequisite for preclinical long-term results after cardiac xenotransplantation.
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Affiliation(s)
- Matthias Längin
- Department of Anaesthesiology, University Hospital, LMU Munich, Munich, Germany
| | - Bruno Reichart
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Stig Steen
- Department of Cardiothoracic Surgery, Lund University and Skåne University Hospital, Lund, Sweden
| | - Trygve Sjöberg
- Department of Cardiothoracic Surgery, Lund University and Skåne University Hospital, Lund, Sweden
| | - Audrius Paskevicius
- Department of Cardiothoracic Surgery, Lund University and Skåne University Hospital, Lund, Sweden
| | - Qiuming Liao
- Department of Cardiothoracic Surgery, Lund University and Skåne University Hospital, Lund, Sweden
| | - Guangqi Qin
- Department of Cardiothoracic Surgery, Lund University and Skåne University Hospital, Lund, Sweden
| | - Maren Mokelke
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Tanja Mayr
- Department of Anaesthesiology, University Hospital, LMU Munich, Munich, Germany
| | - Julia Radan
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Lara Issl
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Ines Buttgereit
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Jiawei Ying
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Ann Kathrin Fresch
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Alessandro Panelli
- Transregional Collaborative Research Center 127, Walter Brendel Centre of Experimental Medicine, LMU Munich, Munich, Germany
| | - Stefanie Egerer
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany
| | - Andrea Bähr
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany
| | - Barbara Kessler
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany
| | - Anastasia Milusev
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Riccardo Sfriso
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Robert Rieben
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | | | - Peter J Murray
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Reinhard Ellgass
- Department of Cardiac Surgery, University Hospital, LMU Munich, Munich, Germany
| | - Christoph Walz
- Institute of Pathology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Nikolai Klymiuk
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany
| | - Eckhard Wolf
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany
| | - Jan-Michael Abicht
- Department of Anaesthesiology, University Hospital, LMU Munich, Munich, Germany
| | - Paolo Brenner
- Department of Cardiac Surgery, University Hospital, LMU Munich, Munich, Germany
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Ramm R, Goecke T, Theodoridis K, Hoeffler K, Sarikouch S, Findeisen K, Ciubotaru A, Cebotari S, Tudorache I, Haverich A, Hilfiker A. Decellularization combined with enzymatic removal of N-linked glycans and residual DNA reduces inflammatory response and improves performance of porcine xenogeneic pulmonary heart valves in an ovine in vivo model. Xenotransplantation 2019; 27:e12571. [PMID: 31769101 DOI: 10.1111/xen.12571] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/01/2019] [Accepted: 11/06/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Limited availability of decellularized allogeneic heart valve substitutes restricts the clinical application thereof. Decellularized xenogeneic valves might constitute an attractive alternative; however, increased immunological hurdles have to be overcome. This study aims for the in vivo effect in sheep of decellularized porcine pulmonary heart valves (dpPHV) enzymatically treated for N-glycan and DNA removal. METHODS dpPHV generated by nine different decelluarization methods were characterized in respect of DNA, hydroxyproline, GAGs, and SDS content. Orthotopic implantation in sheep for six months of five groups of dpPHV (n = 3 each; 3 different decellularization protocols w/o PNGase F and DNase I treatment) allowed the analysis of function and immunological reaction in the ovine host. Allogenic doPHV implantations (n = 3) from a previous study served as control. RESULTS Among the decellularization procedures, Triton X-100 & SDS as well as trypsin & Triton X-100 resulted in highly efficient removal of cellular components, while the extracellular matrix remained intact. In vivo, the functional performance of dpPHV was comparable to that of allogeneic controls. Removal of N-linked glycans and DNA by enzymatic PNGase F and DNase I treatment had positive effects on the clinical performance of Triton X-100 & SDS dpPHV, whereas this treatment of trypsin & Triton X-100 dpPHV induced the lowest degree of inflammation of all tested xenogeneic implants. CONCLUSION Functional xenogeneic heart valve substitutes with a low immunologic load can be produced by decellularization combined with enzymatic removal of DNA and partial deglycosylation of dpPHV.
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Affiliation(s)
- Robert Ramm
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Tobias Goecke
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany.,Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Karolina Theodoridis
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Klaus Hoeffler
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Samir Sarikouch
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Katja Findeisen
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Anatol Ciubotaru
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany.,Cardiac Surgery Center, State Medical and Pharmaceutical University, Chisinau, Moldova
| | - Serghei Cebotari
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany.,Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Igor Tudorache
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany.,Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Axel Haverich
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany.,Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Andres Hilfiker
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany.,Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
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3
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Iwase H, Hara H, Ezzelarab M, Li T, Zhang Z, Gao B, Liu H, Long C, Wang Y, Cassano A, Klein E, Phelps C, Ayares D, Humar A, Wijkstrom M, Cooper DKC. Immunological and physiological observations in baboons with life-supporting genetically engineered pig kidney grafts. Xenotransplantation 2017; 24:10.1111/xen.12293. [PMID: 28303661 PMCID: PMC5397334 DOI: 10.1111/xen.12293] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/22/2016] [Accepted: 01/26/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Genetically engineered pigs could provide a source of kidneys for clinical transplantation. The two longest kidney graft survivals reported to date have been 136 and 310 days, but graft survival >30 days has been unusual until recently. METHODS Donor pigs (n=4) were on an α1,3-galactosyltransferase gene-knockout (GTKO)/human complement regulatory protein (CD46) background (GTKO/CD46). In addition, the pigs were transgenic for at least one human coagulation regulatory protein. Two baboons received a kidney from a six-gene pig (GroupA) and two from a three-gene pig (GroupB). Immunosuppressive therapy was identical in all four cases and consisted of anti-thymoglobulin (ATG)+anti-CD20mAb (induction) and anti-CD40mAb+rapamycin+corticosteroids (maintenance). Anti-TNF-α and anti-IL-6R mAbs were administered to reduce the inflammatory response. Baboons were followed by clinical/laboratory monitoring of immune/coagulation/inflammatory/physiological parameters. At biopsy or euthanasia, the grafts were examined by microscopy. RESULTS The two GroupA baboons remained healthy with normal renal function >7 and >8 months, respectively, but then developed infectious complications. However, no features of a consumptive coagulopathy, eg, thrombocytopenia and reduction of fibrinogen, or of a protein-losing nephropathy were observed. There was no evidence of an elicited anti-pig antibody response, and histology of biopsies taken at approximately 4, 6, and 7 months and at necropsy showed no significant abnormalities. In contrast, both GroupB baboons developed features of a consumptive coagulopathy and required euthanasia on day 12. CONCLUSIONS The combination of (i) a graft from a specific six-gene genetically modified pig, (ii) an effective immunosuppressive regimen, and (iii) anti-inflammatory therapy prevented immune injury, a protein-losing nephropathy, and coagulation dysfunction for >7 months. Although the number of experiments is very limited, our impression is that expression of human endothelial protein C receptor (±CD55) in the graft is important if coagulation dysregulation is to be avoided.
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Affiliation(s)
- Hayato Iwase
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hidetaka Hara
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mohamed Ezzelarab
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tao Li
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Kidney Transplantation, Second Affiliated Hospital of the University of South China, Hengyang, Hunan, China
| | - Zhongqiang Zhang
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
- Department of General Surgery, Second Xiangya Hospital of the Central South University, Changsha, Hunan, China
| | - Bingsi Gao
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Kidney Transplantation, Second Affiliated Hospital of the University of South China, Hengyang, Hunan, China
| | - Hong Liu
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
- Department of General Surgery, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Cassandra Long
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yi Wang
- Center for Kidney Transplantation, Second Affiliated Hospital of the University of South China, Hengyang, Hunan, China
| | - Amy Cassano
- Division of Laboratory Animal Resources, University of Pittsburgh, Pittsburgh, PA, USA
| | - Edwin Klein
- Division of Laboratory Animal Resources, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | - Abhinav Humar
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Martin Wijkstrom
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
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Kwon DJ, Hwang IS, Kim HR, Kim YR, Oh KB, Ock SA, Im GS, Lee JW, Hwang S. Aberrant methylation of Meg3 in alpha1,3-galactosyltransferase knockout pig induced pluripotent stem cells. Anim Cells Syst (Seoul) 2016. [DOI: 10.1080/19768354.2016.1191543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Cooper DKC, Ezzelarab MB, Hara H, Iwase H, Lee W, Wijkstrom M, Bottino R. The pathobiology of pig-to-primate xenotransplantation: a historical review. Xenotransplantation 2016; 23:83-105. [PMID: 26813438 DOI: 10.1111/xen.12219] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/22/2015] [Indexed: 12/16/2022]
Abstract
The immunologic barriers to successful xenotransplantation are related to the presence of natural anti-pig antibodies in humans and non-human primates that bind to antigens expressed on the transplanted pig organ (the most important of which is galactose-α1,3-galactose [Gal]), and activate the complement cascade, which results in rapid destruction of the graft, a process known as hyperacute rejection. High levels of elicited anti-pig IgG may develop if the adaptive immune response is not prevented by adequate immunosuppressive therapy, resulting in activation and injury of the vascular endothelium. The transplantation of organs and cells from pigs that do not express the important Gal antigen (α1,3-galactosyltransferase gene-knockout [GTKO] pigs) and express one or more human complement-regulatory proteins (hCRP, e.g., CD46, CD55), when combined with an effective costimulation blockade-based immunosuppressive regimen, prevents early antibody-mediated and cellular rejection. However, low levels of anti-non-Gal antibody and innate immune cells and/or platelets may initiate the development of a thrombotic microangiopathy in the graft that may be associated with a consumptive coagulopathy in the recipient. This pathogenic process is accentuated by the dysregulation of the coagulation-anticoagulation systems between pigs and primates. The expression in GTKO/hCRP pigs of a human coagulation-regulatory protein, for example, thrombomodulin, is increasingly being associated with prolonged pig graft survival in non-human primates. Initial clinical trials of islet and corneal xenotransplantation are already underway, and trials of pig kidney or heart transplantation are anticipated within the next few years.
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Affiliation(s)
- David K C Cooper
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mohamed B Ezzelarab
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hidetaka Hara
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hayato Iwase
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Whayoung Lee
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Martin Wijkstrom
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Rita Bottino
- Institute for Cellular Therapeutics, Allegheny-Singer Research Institute, Pittsburgh, PA, USA
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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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Kim H, Chee H, Yang J, Hwang S, Han K, Kang J, Park J, Kim J, Lee S, Ock S, Park M, Park K, Byeongchun L, Cho K, Noh J, Park W, Yun I, Ahn C. Outcomes of Alpha 1,3-GT-knockout Porcine Heart Transplants Into a Preclinical Nonhuman Primate Model. Transplant Proc 2013; 45:3085-91. [DOI: 10.1016/j.transproceed.2013.08.049] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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McGregor CGA, Ricci D, Miyagi N, Stalboerger PG, Du Z, Oehler EA, Tazelaar HD, Byrne GW. Human CD55 expression blocks hyperacute rejection and restricts complement activation in Gal knockout cardiac xenografts. Transplantation 2012; 93:686-92. [PMID: 22391577 DOI: 10.1097/tp.0b013e3182472850] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Transgenic expression of human complement regulatory proteins reduces the frequency of hyperacute rejection (HAR) in Gal-positive cardiac xenotransplantation. In this study, we examined the impact of human CD55 (hCD55) expression on a Gal knockout (GTKO) background using pig-to-primate heterotopic cardiac xenotransplantation. METHODS Cardiac xenotransplantation was performed with GTKO (group 1; n=6) and GTKO.hCD55 (group 2; n=5) donor pigs using similar immunosuppression. Cardiac biopsies were obtained 30 min after organ reperfusion. Rejection was characterized by histology and immunohistology. Intragraft gene expression, serum non-Gal antibody, and antibody recovered from rejected hearts were analyzed. RESULTS HAR of a GTKO heart was observed. Remaining grafts developed delayed xenograft rejection. Median survival was 21 and 28 days for groups 1 and 2, respectively. Vascular antibody deposition was uniformly detected 30 min after organ reperfusion and at explant. A higher frequency of vascular C5b deposition was seen in GTKO organs at explant. Serum non-Gal antibody, antibody recovered from the graft, and intragraft gene expression were similar between the groups. CONCLUSION HAR of GTKO hearts without hCD55 may occur. Expression of hCD55 seemed to restrict local complement activation but did not improve graft survival. Chronic vascular antibody deposition with evidence of protracted endothelial cell activation was seen. These observations suggest that non-Gal antibody-induced chronic endothelial cell activation coupled to possible hemostatic incompatibilities may be the primary stimulus for delayed xenograft rejection of GTKO hearts. To avoid possible HAR, future clinical studies should use donors expressing human complement regulatory proteins in the GTKO background.
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Abstract
PURPOSE OF REVIEW Cardiac xenotransplantation (CXTx) remains a promising approach to alleviate the chronic shortage of donor hearts. This review summarizes recent results of heterotopic and orthotopic CXTx, highlights the role of non-Gal antibody in xenograft rejection, and discusses challenges to clinical orthotopic CXTx. RECENT FINDINGS Pigs mutated in the α 1,3 galactosyltransferase gene (GTKO pigs) are devoid of the galactose α1,3 galactose (αGal) carbohydrate antigen. This situation effectively eliminates any role for anti-Gal antibody in GTKO cardiac xenograft rejection. Survival of heterotopic GTKO cardiac xenografts in nonhuman primates continues to increase. GTKO graft rejection commonly involves vascular antibody deposition and variable complement deposition. Non-Gal antibody responses to porcine antigens associated with inflammation, complement, and hemostatic regulation and to new carbohydrate antigens have been identified. Their contribution to rejection remains under investigation. Orthotopic CXTx is limited by early perioperative cardiac xenograft dysfunction (PCXD). However, hearts affected by PCXD recover full cardiac function and orthotopic survival up to 2 months without rejection has been reported. SUMMARY CXTx remains a promising technology for treating end-stage cardiac failure. Genetic modification of the donor and refinement of immunosuppressive regimens have extended heterotopic cardiac xenograft survival from minutes to in excess of 8 months.
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Affiliation(s)
- Guerard W Byrne
- University College London, Institute for Cardiovascular Sciences, London, UK.
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Identification of new carbohydrate and membrane protein antigens in cardiac xenotransplantation. Transplantation 2011; 91:287-92. [PMID: 21119562 PMCID: PMC10022691 DOI: 10.1097/tp.0b013e318203c27d] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND α1,3-Galactosyltransferase gene knockout (GTKO) pigs reduced the significance of antibody to galactose alpha 1,3-galactose (Gal) antigens but did not eliminate delayed xenograft rejection (DXR). We hypothesize that DXR of GTKO organs results from an antibody response to a limited number of non-Gal endothelial cell (EC) membrane antigens. In this study, we screened a retrovirus expression library to identify EC membrane antigens detected after cardiac xenotransplantation. METHODS Expression libraries were made from GT:CD46 and GTKO porcine aortic ECs. Viral stocks were used to infect human embryonic kidney cells (HEK) that were selected by flow cytometry for IgG binding from sensitized cardiac heterotopic xenograft recipients. After three to seven rounds of selection, individual clones were assessed for non-Gal IgG binding. The porcine complementary DNA was recovered by polymerase chain reaction amplification, sequenced, and identified by homology comparisons. RESULTS A total of 199 and 317 clones were analyzed from GT:CD46 and GTKO porcine aortic EC complementary DNA libraries, respectively. Sequence analysis identified porcine CD9, CD46, CD59, and the EC protein C receptor. We also identified porcine annexin A2 and a glycosyltransferase with homology to the human β1,4 N-acetylgalactosaminyl transferase 2 gene. CONCLUSION The identified proteins include key EC functions and suggest that non-Gal antibody responses may compromise EC functions and thereby contribute to DXR. Recovery of the porcine β1,4 N-acetylgalactosaminyl transferase 2 suggests that an antibody response to a SD-like carbohydrate may represent a new carbohydrate moiety involved in xenotransplantation. The identification of these porcine gene products may lead to further donor modification to enhance resistance to DXR and further reduce the level of xenograft antigenicity.
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Pierson RN, Dorling A, Ayares D, Rees MA, Seebach JD, Fishman JA, Hering BJ, Cooper DKC. Current status of xenotransplantation and prospects for clinical application. Xenotransplantation 2009; 16:263-80. [PMID: 19796067 PMCID: PMC2866107 DOI: 10.1111/j.1399-3089.2009.00534.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Xenotransplantation is one promising approach to bridge the gap between available human cells, tissues, and organs and the needs of patients with diabetes or end-stage organ failure. Based on recent progress using genetically modified source pigs, improving results with conventional and experimental immunosuppression, and expanded understanding of residual physiologic hurdles, xenotransplantation appears likely to be evaluated in clinical trials in the near future for some select applications. This review offers a comprehensive overview of known mechanisms of xenograft injury, a contemporary assessment of preclinical progress and residual barriers, and our opinions regarding where breakthroughs are likely to occur.
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Affiliation(s)
- Richard N Pierson
- Division of Cardiac Surgery, Department of Surgery, University of Maryland, Baltimore VAMC, Baltimore, MD 21201, USA.
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Matsunari H, Nagashima H. Application of genetically modified and cloned pigs in translational research. J Reprod Dev 2009; 55:225-30. [PMID: 19571468 DOI: 10.1262/jrd.20164] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pigs are increasingly being recognized as good large-animal models for translational research, linking basic science to clinical applications in order to establish novel therapeutics. This article reviews the current status and future prospects of genetically modified and cloned pigs in translational studies. It also highlights pigs specially designed as disease models, for xenotransplantation or to carry cell marker genes. Finally, use of porcine somatic stem and progenitor cells in preclinical studies of cell transplantation therapy is also discussed.
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Affiliation(s)
- Hitomi Matsunari
- Laboratory of Developmental Engineering, Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki 214-8571, Japan
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Kim YG, Shin DS, Yang YH, Gil GC, Park CG, Mimura Y, Cooper DK, Rudd PM, Dwek RA, Lee YS, Kim BG. High-Throughput Screening of Glycan-Binding Proteins Using Miniature Pig Kidney N-Glycan-Immobilized Beads. ACTA ACUST UNITED AC 2008; 15:215-23. [DOI: 10.1016/j.chembiol.2008.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2007] [Revised: 01/27/2008] [Accepted: 02/05/2008] [Indexed: 12/14/2022]
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Cooper DKC, Dorling A, Pierson RN, Rees M, Seebach J, Yazer M, Ohdan H, Awwad M, Ayares D. Alpha1,3-galactosyltransferase gene-knockout pigs for xenotransplantation: where do we go from here? Transplantation 2007; 84:1-7. [PMID: 17627227 DOI: 10.1097/01.tp.0000260427.75804.f2] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The ability to genetically engineer pigs that no longer express the Galalpha1,3Gal (Gal) oligosaccharide has been a significant step toward the clinical applicability of xenotransplantation. Using a chronic immunosuppressive regimen based on costimulatory blockade, hearts from these pigs have survived from 2 to 6 months in baboons. Graft failure was predominantly from the development of a thrombotic microangiopathy. Potential contributing factors include the presence of preformed anti-nonGal antibodies or the development of low levels of elicited antibodies to nonGal antigens, natural killer (NK) cell or macrophage activity, and inherent coagulation dysregulation between pigs and primates. The breeding of pigs transgenic for an "anticoagulant" gene, such as human tissue factor pathway inhibitor, hirudin, or CD39, or lacking the gene for the prothrombinase, fibrinogen-like protein-2, is anticipated to inhibit the change in the endothelium to a procoagulant state that takes place in the pig organ after transplantation. The identification of the targets for anti-nonGal antibodies and/or human macrophages might allow further genetic modification of the pig, and xenogeneic NK cell recognition and activation may be inhibited by the transgenic expression of human leukocyte antigen molecules and/or by blocking the function of activating NK receptors. The ultimate goal of induction of T-cell tolerance may be possible only if these hurdles in the coagulation system and innate immunity can be overcome.
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Affiliation(s)
- David K C Cooper
- The Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
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Using α1,3-galactosyltransferase gene-knockout pig organs in nonhuman primates. Curr Opin Organ Transplant 2007. [DOI: 10.1097/mot.0b013e3280146495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kearns-Jonker M, Barteneva N, Mencel R, Hussain N, Shulkin I, Xu A, Yew M, Cramer DV. Use of molecular modeling and site-directed mutagenesis to define the structural basis for the immune response to carbohydrate xenoantigens. BMC Immunol 2007; 8:3. [PMID: 17352819 PMCID: PMC1851715 DOI: 10.1186/1471-2172-8-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2006] [Accepted: 03/12/2007] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Natural antibodies directed at carbohydrates reject porcine xenografts. They are initially expressed in germline configuration and are encoded by a small number of structurally-related germline progenitors. The transplantation of genetically-modified pig organs prevents hyperacute rejection, but delayed graft rejection still occurs, partly due to humoral responses. IgVH genes encoding induced xenoantibodies are predominantly, not exclusively, derived from germline progenitors in the VH3 family. We have previously identified the immunoglobulin heavy chain genes encoding VH3 xenoantibodies in patients and primates. In this manuscript, we complete the structural analysis of induced xenoantibodies by identifying the IgVH genes encoding the small proportion of VH4 xenoantibodies and the germline progenitors encoding xenoantibody light chains. This information has been used to define the xenoantibody/carbohydrate binding site using computer-simulated modeling. RESULTS The VH4-59 gene encodes antibodies in the VH4 family that are induced in human patients mounting active xenoantibody responses. The light chain of xenoantibodies is encoded by DPK5 and HSIGKV134. The structural information obtained by sequencing analysis was used to create computer-simulated models. Key contact sites for xenoantibody/carbohydrate interaction for VH3 family xenoantibodies include amino acids in sites 31, 33, 50, 57, 58 and the CDR3 region of the IgVH gene. Site-directed mutagenesis indicates that mutations in predicted contact sites alter binding to carbohydrate xenoantigens. Computer-simulated modeling suggests that the CDR3 region directly influences binding. CONCLUSION Xenoantibodies induced during early and delayed xenograft responses are predominantly encoded by genes in the VH3 family, with a small proportion encoded by VH4 germline progenitors. This restricted group can be identified by the unique canonical structure of the light chain, heavy chain and CDR3. Computer-simulated models depict this structure with accuracy, as confirmed by site-directed mutagenesis. Computer-simulated drug design using computer-simulated models may now be applied to develop new drugs that may enhance the survival of xenografted organs.
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Affiliation(s)
- Mary Kearns-Jonker
- Department of Cardiothoracic Surgery, Saban Research Institute of the Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Mailstop #137, Los Angeles, CA 90027 USA
| | - Natasha Barteneva
- Department of Cardiothoracic Surgery, Saban Research Institute of the Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Mailstop #137, Los Angeles, CA 90027 USA
| | - Robert Mencel
- Department of Cardiothoracic Surgery, Saban Research Institute of the Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Mailstop #137, Los Angeles, CA 90027 USA
| | - Namath Hussain
- Department of Cardiothoracic Surgery, Saban Research Institute of the Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Mailstop #137, Los Angeles, CA 90027 USA
| | - Irina Shulkin
- Department of Cardiothoracic Surgery, Saban Research Institute of the Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Mailstop #137, Los Angeles, CA 90027 USA
| | - Alan Xu
- Department of Cardiothoracic Surgery, Saban Research Institute of the Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Mailstop #137, Los Angeles, CA 90027 USA
| | - Margaret Yew
- Department of Cardiothoracic Surgery, Saban Research Institute of the Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Mailstop #137, Los Angeles, CA 90027 USA
| | - Donald V Cramer
- Department of Cardiothoracic Surgery, Saban Research Institute of the Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Mailstop #137, Los Angeles, CA 90027 USA
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Horvath-Arcidiacono JA, Porter CM, Bloom ET. Human NK cells can lyse porcine endothelial cells independent of their expression of Galalpha(1,3)-Gal and killing is enhanced by activation of either effector or target cells. Xenotransplantation 2006; 13:318-27. [PMID: 16768725 DOI: 10.1111/j.1399-3089.2006.00316.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Xenotransplantation of pig organs may provide an approach to alleviate the severe shortage of human organs. Natural antibodies against Galalpha(1,3)-Gal (alphaGal) epitopes cause hyperacute rejection of pig organs in primates. However, evidence for the role of alphaGal in the natural killer (NK) cell-mediated xenoresponse has been contradictory. METHODS We investigated the recognition of alphaGal by human NK cells using endo-beta-galactosidase C, an enzyme that cleaves alphaGal, and endothelial cells (EC) from alpha1,3-galactosyltransferase null pigs that do not synthesize alphaGal. Endo-beta-galactosidase C treatment variably reduced the susceptibility of porcine EC to lysis by fresh human NK cells. RESULTS Removal of alphaGal from porcine EC using endo-beta-galactosidase C, produced variable results, i.e. cytotoxicity was decreased in half of the human NK cell donors tested. The two EC strains from alphaGal-/- pigs were marginally, and not significantly, less susceptible to lysis by naïve human NK cells compared with alphaGal-expressing cells obtained from animals from the same herd, but these differences were not statistically significant (P > 0.10). Treatment of porcine EC with recombinant human tumor necrosis factor (TNF)-alpha, which is known to activate porcine EC, enhanced the susceptibility of all target cells to lysis by fresh human NK cells. Surface expression of MHC or adhesion molecules on alphaGal-/- cells, compared with wild type cells, showed no consistent difference in either MHC or adhesion molecules CD106 (VCAM-1), CD31 (PECAM) or CD62E (E-selectin), either with or without TNF-alpha stimulation, that could explain the differential susceptibility to lysis. Strikingly, all alphaGal-/- and wild type EC exhibited similar susceptibility to human NK cells that had been cultured for 5 days with or without interleukin-2. CONCLUSIONS These findings demonstrate that human NK cells can kill porcine targets in the absence of alphaGal, and donor variability plays a major role in whether alphaGal has a role in determining susceptibility of porcine EC to lysis. Moreover, susceptibility to lysis of alphaGal null EC is enhanced to the level of wild type EC by activation of either effector or target cells. Elimination of alphaGal alone from source pigs will be insufficient to circumvent the NK cell mediated destruction of porcine EC.
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Affiliation(s)
- Judith A Horvath-Arcidiacono
- Gene Transfer and Immunogenicity Branch, Division of Cellular and Gene Therapies, Office of Cellular, Tissue, and Gene Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Bethesda, MD 20892, USA
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Xenotransplantation: the road ahead. Curr Opin Organ Transplant 2006. [DOI: 10.1097/01.mot.0000218928.96901.b1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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