1
|
Wang B, Sierad LN, Mercuri JJ, Simionescu A, Simionescu DT, Williams LN, Vela R, Bajona P, Peltz M, Ramaswamy S, Hong Y, Liao J. Structural and biomechanical characterizations of acellular porcine mitral valve scaffolds: anterior leaflets, posterior leaflets, and chordae tendineae. ENGINEERED REGENERATION 2022; 3:374-386. [PMID: 38362305 PMCID: PMC10869114 DOI: 10.1016/j.engreg.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Mitral valve (MV) tissue engineering is still in its early stage, and one major challenge in MV tissue engineering is to identify appropriate scaffold materials. With the potential of acellular MV scaffolds being demonstrated recently, it is important to have a full understanding of the biomechanics of the native MV components and their acellular scaffolds. In this study, we have successfully characterized the structural and mechanical properties of porcine MV components, including anterior leaflet (AL), posterior leaflet (PL), strut chordae, and basal chordae, before and after decellularization. Quantitative DNA assay showed more than 90% reduction in DNA content, and Griffonia simplicifolia (GS) lectin immunohistochemistry confirmed the complete lack of porcine α-Gal antigen in the acellular MV components. In the acellular AL and PL, the atrialis, spongiosa, and fibrosa trilayered structure, along with its ECM constitutes, i.e., collagen fibers, elastin fibers, and portion of GAGs, were preserved. Nevertheless, the ECM of both AL and PL experienced a certain degree of disruption, exhibiting a less dense, porous ECM morphology. The overall anatomical morphology of the strut and basal chordae were also maintained after decellularization, with longitudinal morphology experiencing minimum disruption, but the cross-sectional morphology exhibiting evenly-distributed porous structure. In the acellular AL and PL, the nonlinear anisotropic biaxial mechanical behavior was overall preserved; however, uniaxial tensile tests showed that the removal of cellular content and the disruption of structural ECM did result in small decreases in maximum tensile modulus, tissue extensibility, failure stress, and failure strain for both MV leaflets and chordae.
Collapse
Affiliation(s)
- Bo Wang
- Joint Department of Biomedical Engineering, Medical College of Wisconsin and Marquette University, Milwaukee, WI 53226, United States
| | - Leslie N. Sierad
- Department of Bioengineering, Clemson University, Clemson, SC 29634, United States
| | - Jeremy J. Mercuri
- Department of Bioengineering, Clemson University, Clemson, SC 29634, United States
| | - Agneta Simionescu
- Department of Bioengineering, Clemson University, Clemson, SC 29634, United States
| | - Dan T. Simionescu
- Department of Bioengineering, Clemson University, Clemson, SC 29634, United States
| | - Lakiesha N. Williams
- Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, United States
| | - Ryan Vela
- Department of Cardiovascular and Thoracic Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Pietro Bajona
- Department of Cardiovascular and Thoracic Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
- Allegheny Health Network-Drexel University College of Medicine, Pittsburgh, PA 15212, United States
| | - Matthias Peltz
- Department of Cardiovascular and Thoracic Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Sharan Ramaswamy
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, United States
| | - Yi Hong
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX 76010, United States
| | - Jun Liao
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX 76010, United States
| |
Collapse
|
2
|
Zhou M, Lu Y, Zhao C, Zhang J, Cooper DKC, Xie C, Song Z, Gao H, Qu Z, Lin S, Deng Y, Hara H, Zhan Y, Jiang Z, Dai Y, Wu C, Cai Z, Mou L. Circulating pig-specific DNA as a novel biomarker for monitoring xenograft rejection. Xenotransplantation 2019; 26:e12522. [PMID: 31077480 DOI: 10.1111/xen.12522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 03/29/2019] [Accepted: 04/15/2019] [Indexed: 01/12/2023]
Abstract
Monitoring for immune rejection is crucial for long-term survival of pig xenografts. Circulating DNA is a promising non-invasive biomarker for either organ injury or response to therapy. In this study, circulating pig-specific DNA (cpsDNA) was monitored during xenograft rejection. Potential targets of cpsDNA were selected by in silico analysis, and species specificity of selected primers was confirmed by PCR. Subsequently, cpsDNA as a biomarker was evaluated using a complement-dependent cytotoxicity (CDC) assay in vitro. Then, early diagnosis and response to rapamycin were assessed by an in vivo imaging model of pig-to-mouse cell transplantation. Finally, cpsDNA was monitored in a pig-to-monkey artery patch transplantation model. The results showed that (a) a method of cpsDNA quantitation was established for application in mouse and nonhuman primate models; (b) cpsDNA reflected CDC in vitro; (c) cpsDNA in vivo mirrored xenograft rejection, and correlated with xenograft loss in pig-to-mouse cell transplantation; (d) cpsDNA was significantly reduced when rapamycin was administered; and (e) dynamic cpsDNA was detectable in pig-to-monkey artery patch transplantation. In conclusion, measurement of cpsDNA could prove to be a less invasive, but more specific and sensitive low-cost biomarker enabling monitoring of xenograft rejection and the response to immunosuppressive therapy.
Collapse
Affiliation(s)
- Ming Zhou
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - Ying Lu
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - Chengjiang Zhao
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - Junfang Zhang
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Chongwei Xie
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - Zongpei Song
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - Hanchao Gao
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - Zepeng Qu
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - Shan Lin
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - YangYang Deng
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Yongqiang Zhan
- Department of Hepatopancreatobiliary Surgery, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Zhengda Jiang
- Biology Department, Hendrix College, Conway, Arkansas, USA
| | - Yifan Dai
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Changyou Wu
- Institute of Immunology, Zhongshan School of Medicine, Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, Sun Yat-sen University, Guangzhou, China
| | - Zhiming Cai
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Lisha Mou
- Shenzhen Xenotransplantation Research and Development Center, Institute of Translational Medicine, Shenzhen University Health Science Center, Shenzhen University School of Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China
| |
Collapse
|
3
|
Harris DG, Benipal PK, Cheng X, Burdorf L, Azimzadeh AM, Pierson RN. Four-dimensional characterization of thrombosis in a live-cell, shear-flow assay: development and application to xenotransplantation. PLoS One 2015; 10:e0123015. [PMID: 25830912 PMCID: PMC4382176 DOI: 10.1371/journal.pone.0123015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 02/26/2015] [Indexed: 02/01/2023] Open
Abstract
Background Porcine xenografts are a promising source of scarce transplantable organs, but stimulate intense thrombosis of human blood despite targeted genetic and pharmacologic interventions. Current experimental models do not enable study of the blood/endothelial interface to investigate adhesive interactions and thrombosis at the cellular level under physiologic conditions. The purpose of this study was to develop and validate a live-cell, shear-flow based thrombosis assay relevant to general thrombosis research, and demonstrate its potential in xenotransplantation applications. Methodology/Principal Findings Confluent wild-type (WT, n = 48) and Gal transferase knock-out (GalTKO, which resist hyperacute rejection; n = 11) porcine endothelia were cultured in microfluidic channels. To mimic microcirculatory flow, channels were perfused at 5 dynes/cm2 and 37°C with human blood stained to fluorescently label platelets. Serial fluorescent imaging visualized percent surface area coverage (SA, for adhesion of labeled cells) and total fluorescence (a metric of clot volume). Aggregation was calculated by the fluorescence/SA ratio (FR). WT endothelia stimulated diffuse platelet adhesion (SA 65 ± 2%) and aggregation (FR 120 ± 1 a.u.), indicating high-grade thrombosis consistent with the rapid platelet activation and consumption seen in whole-organ lung xenotransplantation models. Experiments with antibody blockade of platelet aggregation, and perfusion of syngeneic and allo-incompatible endothelium was used to verify the biologic specificity and validity of the assay. Finally, with GalTKO endothelia thrombus volume decreased by 60%, due primarily to a 58% reduction in adhesion (P < 0.0001 each); importantly, aggregation was only marginally affected (11% reduction, P < 0.0001). Conclusions/Significance This novel, high-throughput assay enabled dynamic modeling of whole-blood thrombosis on intact endothelium under physiologic conditions, and allowed mechanistic characterization of endothelial and platelet interactions. Applied to xenogeneic thrombosis, it enables future studies regarding the effect of modifying the porcine genotype on sheer-stress-dependent events that characterize xenograft injury. This in-vitro platform is likely to prove broadly useful to study thrombosis and endothelial interactions under dynamic physiologic conditions.
Collapse
Affiliation(s)
- Donald G Harris
- Division of General Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America; Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Prabhjot K Benipal
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Xiangfei Cheng
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Lars Burdorf
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Agnes M Azimzadeh
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Richard N Pierson
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States of America; Surgical Care Clinical Center, VA Maryland Health Care System, Baltimore, Maryland, United States of America
| |
Collapse
|
4
|
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.
Collapse
Affiliation(s)
- Agnes M Azimzadeh
- Division of Cardiac Surgery, University of Maryland and VAMC Baltimore, Baltimore, MD, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Mathieux E, Nerrière-Daguin V, Lévèque X, Michel-Monigadon D, Durand T, Bonnamain V, Ménoret S, Anegon I, Naveilhan P, Neveu I. IgG response to intracerebral xenotransplantation: specificity and role in the rejection of porcine neurons. Am J Transplant 2014; 14:1109-19. [PMID: 24612827 DOI: 10.1111/ajt.12656] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/25/2013] [Accepted: 12/14/2013] [Indexed: 01/25/2023]
Abstract
Xenogenic fetal neuroblasts are considered as a potential source of transplantable cells for the treatment of neurodegenerative diseases, but immunological barriers limit their use in the clinic. While considerable work has been performed to decipher the role of the cellular immune response in the rejection of intracerebral xenotransplants, there is much still to learn about the humoral reaction. To this end, the IgG response to the transplantation of fetal porcine neural cells (PNC) into the rat brain was analyzed. Rat sera did not contain preformed antibodies against PNC, but elicited anti-porcine IgG was clearly detected in the host blood once the graft was rejected. Only the IgG1 and IgG2a subclasses were up-regulated, suggesting a T-helper 2 immune response. The main target of these elicited IgG antibodies was porcine neurons, as determined by double labeling in vitro and in vivo. Complement and anti-porcine IgG were present in the rejecting grafts, suggesting an active role of the host humoral response in graft rejection. This hypothesis was confirmed by the prolonged survival of fetal porcine neurons in the striatum of immunoglobulin-deficient rats. These data suggest that the prolonged survival of intracerebral xenotransplants relies on the control of both cell-mediated and humoral immune responses.
Collapse
Affiliation(s)
- E Mathieux
- INSERM, UMR 1064, Center for Research in Transplantation and Immunology, Nantes, France; CHU de Nantes, Institut de Transplantation et de Recherche en Transplantation, ITERT, Nantes, France; LUNAM Université, Université de Nantes, Faculté de Médecine, Nantes, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Wang B, Tedder ME, Perez CE, Wang G, de Jongh Curry AL, To F, Elder SH, Williams LN, Simionescu DT, Liao J. Structural and biomechanical characterizations of porcine myocardial extracellular matrix. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:1835-1847. [PMID: 22584822 PMCID: PMC3523096 DOI: 10.1007/s10856-012-4660-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 04/23/2012] [Indexed: 05/30/2023]
Abstract
Extracellular matrix (ECM) of myocardium plays an important role to maintain a multilayered helical architecture of cardiomyocytes. In this study, we have characterized the structural and biomechanical properties of porcine myocardial ECM. Fresh myocardium were decellularized in a rotating bioreactor using 0.1 % sodium dodecyl sulfate solution. Masson's trichrome staining and SEM demonstrated the removal of cells and preservation of the interconnected 3D cardiomyocyte lacunae. Movat's pentachrome staining showed the preservation of cardiac elastin ultrastructure and vascular elastin distribution/alignment. DNA assay result confirmed a 98.59 % reduction in DNA content; the acellular myocardial scaffolds were found completely lack of staining for the porcine α-Gal antigen; and the accelerating enzymatic degradation assessment showed a constant degradation rate. Tensile and shear properties of the acellular myocardial scaffolds were also evaluated. Our observations showed that the acellular myocardial ECM possessed important traits of biodegradable scaffolds, indicating the potentials in cardiac regeneration and whole heart tissue engineering.
Collapse
Affiliation(s)
- Bo Wang
- Department of Agricultural and Biological Engineering, Computational Manufacturing and Design, CAVS, Mississippi State University, Starkville, MS 39762, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Tedder ME, Simionescu A, Chen J, Liao J, Simionescu DT. Assembly and testing of stem cell-seeded layered collagen constructs for heart valve tissue engineering. Tissue Eng Part A 2010; 17:25-36. [PMID: 20673028 DOI: 10.1089/ten.tea.2010.0138] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Tissue engineering holds great promise for treatment of valvular diseases. Despite excellent progress in the field, current approaches do not fully take into account each patient's valve anatomical uniqueness, the presence of a middle spongiosa cushion that allows shearing of external fibrous layers (fibrosa and ventricularis), and the need for autologous valvular interstitial cells. In this study we propose a novel approach to heart valve tissue engineering based on bioreactor conditioning of mesenchymal stem cell-seeded, valve-shaped constructs assembled from layered collagenous scaffolds. Fibrous scaffolds were prepared by decellularization of porcine pericardium and spongiosa scaffolds by decellularization and elastase treatment of porcine pulmonary arteries. To create anatomically correct constructs, we created silicone molds from native porcine aortic valves, dried two identical fibrous scaffolds onto the molds, and stabilized them with penta-galloyl-glucose a reversible collagen-binding polyphenol that reduces biodegradation. The layers were fused with a protein/aldehyde scaffold bio-adhesive and neutralized to reduce cytotoxicity. Spongiosa scaffolds, seeded with human bone marrow-derived stem cells, were inserted within the valve-shaped layered scaffolds and sutured inside the original aortic root. The final product was mounted in a heart valve bioreactor and cycled in cell culture conditions. Most cells were alive after 8 days, elongated significantly, and stained positive for vimentin, similar to native human valvular interstitial cells, indicating feasibility of our approach.
Collapse
Affiliation(s)
- Mary E Tedder
- Department of Bioengineering, Clemson University, Clemson, South Carolina 29634-0905, USA
| | | | | | | | | |
Collapse
|
8
|
Design and Testing of a Pulsatile Conditioning System for Dynamic Endothelialization of Polyphenol-Stabilized Tissue Engineered Heart Valves. Cardiovasc Eng Technol 2010; 1:138-153. [PMID: 21340043 DOI: 10.1007/s13239-010-0014-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Heart valve tissue engineering requires biocompatible and hemocompatible scaffolds that undergo remodeling and repopulation, but that also withstand harsh mechanical forces immediately following implantation. We hypothesized that reversibly stabilized acellular porcine valves, seeded with endothelial cells and conditioned in pulsatile bioreactors would pave the way for next generations of tissue engineered heart valves (TEHVs). A novel valve conditioning system was first designed, manufactured and tested to adequately assess TEHVs. The bioreactor created proper closing and opening of valves and allowed for multiple mounting methods in sterile conditions. Porcine aortic heart valve roots were decellularized by chemical extractions and treated with penta-galloyl glucose (PGG) for stabilization. Properties of the novel scaffolds were evaluated by testing resistance to collagenase and elastase, biaxial mechanical analysis, and thermal denaturation profiles. Porcine aortic endothelial cells were seeded onto the leaflets and whole aortic roots were mounted within the dynamic pulsatile heart valve bioreactor system under physiologic pulmonary valve pressures and analyzed after 17 days for cell viability, morphology, and metabolic activity. Our tissue preparation methods effectively removed cells, including the potent α-Gal antigen, while leaving a well preserved extra-cellular matrix scaffold with adequate mechanical properties. PGG enhanced stabilization of extracellular matrix components but also showed the ability to be reversible. Engineered valve scaffolds encouraged attachment and survival of endothelial cells for extended periods and showed signs of widespread cell coverage after conditioning. Our novel approach shows promise toward development of sturdy and durable TEHVs capable of remodeling and cellular repopulation.
Collapse
|
9
|
Resistance to anti-xenogeneic response by combining α-Gal silencing with HO-1 upregulation. Transpl Immunol 2008; 19:202-8. [DOI: 10.1016/j.trim.2008.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Revised: 06/05/2008] [Accepted: 06/09/2008] [Indexed: 11/23/2022]
|
10
|
Roy BB, Jinno-Oue A, Shinagawa M, Shimizu A, Tamura K, Shimizu N, Tanaka A, Hoshino H. Isolation of the feline alpha1,3-galactosyltransferase gene, expression in transfected human cells and its phylogenetic analysis. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2006; 306:59-69. [PMID: 16217797 DOI: 10.1002/jez.b.21072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The enzyme alpha 1,3-galactosyltransferase (alpha1,3-GT), which catalyzes synthesis of terminal alpha-galactosyl epitopes (Gal alpha1,3Gal beta1-4GlcNAc-R), is produced in non-primate mammals, prosimians and new-world monkeys, but not in old-world monkeys, apes and humans. We cloned and sequenced a cDNA that contains the coding sequence of the feline alpha1,3-GT gene. Flow cytometric analysis demonstrated that the alpha-galactosyl epitope was expressed on the surface of a human cell line transduced with an expression vector containing this cDNA, and this alpha-galactosyl epitope expression subsided by alpha-galactosidase treatment. The open reading frame of the feline alpha1,3-GT cDNA is 1,113 base pairs in length and encodes 371 amino acids. The nucleotide sequence and its deduced amino acid sequence of the feline alpha1,3-GT gene are 88-90% and 85-87%, respectively, similar to the reported sequences of the bovine, porcine, marmoset and cebus monkey alpha1,3-GT genes, while they are 88% and 82-83%, respectively, similar to those of the orangutan and human alpha1,3-GT pseudogenes, and 81% and 77%, respectively, similar to the murine alpha1,3-GT gene. Thus, the alpha1,3-GT genes and pseudogenes of mammals are highly similar. Ratios of non-synonymous nucleotide changes among the primate pseudogenes as well as the primate genes are still higher than the ratios of non-primates, suggesting that the primate alpha1,3-GT genes tend to be divergent.
Collapse
Affiliation(s)
- Bibhuti Bhusan Roy
- Department of Virology and Preventive Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Wu G, Pfeiffer S, Schröder C, Zhang T, Nguyen BN, Lea W, Kelishadi S, Atkinson JB, Schuurman HJ, White DJG, Azimzadeh AM, Pierson RN. Local or short-term systemic costimulatory molecule blockade prolongs rat corneal allograft survival. Xenotransplantation 2005; 12:197-208. [PMID: 15807770 DOI: 10.1111/j.1399-3089.2005.00221.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Costimulatory molecule blockade with antibody-based immunosuppressive agents has been shown to prolong the survival of many types of allograft. The effects were evaluated of local costimulatory molecule blockade with different CTLA4-Ig constructs and of systemic, short-term treatment with an anti-CD28 monoclonal antibody on orthotopic corneal allograft survival in the rat. METHODS Adult Fischer-344 rats underwent Wistar-Furth orthotopic corneal grafts. The rats were treated with two different CTLA4-fusion proteins administered intraocularly in the perioperative period, or systemically with anti-CD28 monoclonal antibody JJ319. Corneal graft survival was determined by daily slit-lamp examination. The day of rejection was defined as the first postoperative day on which the iris margin was no longer clearly visible through the corneal graft. RESULTS Local administration of CTLA4-fusion protein with mutated immunoglobulin constant region domains via a single perioperative intraocular injection prolonged corneal graft survival modestly but significantly (P < 0.05), in contrast to a CTLA4-fusion protein with wild-type immunoglobulin domains, which had no effect on graft survival (P > 0.5). Systemic short-term administration of 400 microg total of an anti-CD28 monoclonal antibody also prolonged corneal graft survival significantly (P < 0.05) and was more effective than systemic administration of 2 mg total of CTLA4-fusion protein (P < 0.05). CONCLUSIONS Local administration of CTLA4-fusion protein with mutated (non-functional) immunoglobulin domains or systemic administration of anti-CD28 monoclonal antibody can prolong corneal allograft survival in the rat.
Collapse
Affiliation(s)
- Guosheng Wu
- University of Maryland and Baltimore VAMC, Baltimore, MD 21201, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Kirchhof N, Shibata S, Wijkstrom M, Kulick DM, Salerno CT, Clemmings SM, Heremans Y, Galili U, Sutherland DER, Dalmasso AP, Hering BJ. Reversal of diabetes in non-immunosuppressed rhesus macaques by intraportal porcine islet xenografts precedes acute cellular rejection. Xenotransplantation 2004; 11:396-407. [PMID: 15303976 DOI: 10.1111/j.1399-3089.2004.00157.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND The functional response and immunobiology of primarily non-vascularized islet cell xenografts remain poorly defined in non-human primates. METHODS We transplanted 20,000 adult porcine islet equivalents/kg (purified and cultured for 48-h) intraportally into six streptozotocin-diabetic and two non-diabetic rhesus macaques. Two recipients were killed at various intervals post-transplant for histologic examination of livers bearing xenografts. RESULTS Plasma glucose levels in diabetic recipients averaged 94 mg/dl at 12 h, 92 mg/dl at 24 h, 147 mg/dl at 48 h, and 157 mg/dl at 72 h post-transplant. Serum porcine C-peptide was present in eight of eight recipients at 12 h, in five of six at 24 h, in four of four at 48 h, and in one of two at 72 h post-transplant. C3a and SC5b-9 plasma levels increased at 12 h post-transplant and returned to pre-transplant levels by 24 h. IgG, IgM anti-pig and anti-Gal IgG serum antibody levels did not increase post-transplant. Rejection was initiated by IgM and complement deposition on islets. Neutrophils dominated the cellular infiltrate at 12 h; CD4+ and CD8+ T cells were the main infiltrating cells at 24, 48, and 72 h; and macrophages increasingly infiltrated xenografts starting at 24 h post-transplant. Numerous xenoislets were present at all time points; their proportion without intraislet infiltrates decreased from 65% at 24 h to 17% at 72 h post-transplant. CONCLUSIONS Pig-to-primate intraportal islet xenografts reverse diabetes and the majority of intraportally transplanted xenogeneic islets are not subject to hyperacute rejection. They undergo acute cellular rejection mediated by CD4+- and CD8+ T cells and macrophages.
Collapse
Affiliation(s)
- Nicole Kirchhof
- Diabetes Institute for Immunology and Transplantation, University of Minnesota, Minneapolis, MN 55455, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Farivar RS, Filsoufi F, Adams DH. Mechanisms of Gal(alpha)1-3Gal(beta)1-4GlcNAc-R (alphaGal) expression on porcine valve endothelial cells. J Thorac Cardiovasc Surg 2003; 125:306-14. [PMID: 12579099 DOI: 10.1067/mtc.2003.76] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE We have previously reported that porcine valve endothelium does not express immunodetectable levels of the carbohydrate Gal(alpha)1-3Galbeta1-4GlcNAc-R (known as alphaGal), suggesting that fresh porcine valve may be immunoprivileged. In this study, we further investigated the mechanisms of alphaGal expression on porcine valve endothelial cells. METHODS Primary cultures of porcine valvular endothelial cells were established and compared with porcine aortic endothelial cells and human vein endothelial cells. Immunoblotting, reverse transcriptase-polymerase chain reaction, and flow cytometry were used to compare the expression of alphaGal at both the protein and messenger RNA levels. RESULTS Porcine valvular endothelial cells grew rapidly on a gelatin substrate. Similar to our previous in vivo results, valve endothelial cells expressed alphaGal much less intensely than did aortic endothelial cells. Porcine aortic endothelial cells expressed an isolectin B4 (isolectin B4 lectin Bandeiraea simplicifolia) immunodetectable band at 135 kd that was not visible on porcine valve endothelial cells or on human vein endothelial cells. Reverse transcriptase-polymerase chain reaction documented three transcripts of the alphaGal gene that were identically expressed on porcine valve and aortic endothelial cells. Furthermore, flow cytometry showed an almost identical surface profile between porcine aortic and valve endothelial cells, in contrast with human vein endothelial cells. CONCLUSIONS Cultures of primary valve endothelial cells were established and exhibited similar phenotypic patterns in vitro to those we have previously documented in vivo. RNA and flow cytometric analyses documented no difference between the RNA expression and surface protein profile for alphaGal, although whole-cell extracts demonstrated an immunodetectable band on Western blotting that was present on aortic endothelial cells but not on valve endothelial cells. These findings clarify the mechanism of expression of alpha1,3galactosyltransferase gene expression in valve endothelial cells, suggesting that delayed rejection of fresh porcine cardiac valves may occur.
Collapse
Affiliation(s)
- R Saeid Farivar
- Department of Surgery, Brigham and Women's Hospital, Boston, Mass., USA
| | | | | |
Collapse
|
14
|
Roos A, Daha MR. Antibody-mediated activation of the classical complement pathway in xenograft rejection. Transpl Immunol 2002; 9:257-70. [PMID: 12180840 DOI: 10.1016/s0966-3274(02)00042-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Transplant rejection is a multifactorial process involving complex interactions between components of the innate and the acquired immune system. In view of the shortage of donor organs available for transplantation, xenotransplantation of pig organs into man has been considered as a potential solution. However, in comparison to allografts, xenografts are subject to extremely potent rejection processes that are currently incompletely defined. Consequently, an appropriate and safe treatment protocol ensuring long-term graft survival is not yet available. The first barrier that has to be taken for a xenograft is hyperacute rejection, a rapid process induced by the binding of pre-formed antibodies from the host to the graft endothelium, followed by activation of the classical complement pathway. The present review concentrates on the role of antibodies and complement in xenograft rejection as well as on the approaches for treatment that target these components. The first part focuses on porcine xenoantigens that are recognized by human xenoreactive antibodies and the different treatment strategies that aim on interference in antibody binding. The second part of the review deals with complement activation by xenoreactive antibodies, and summarizes the role of complement in the induction of endothelial cell damage and cell activation. Finally, various options that are currently under development for complement inhibition are discussed, with special reference to the specific inhibition of the classical complement pathway by soluble complement inhibitors.
Collapse
Affiliation(s)
- Anja Roos
- Department of Nephrology, Leiden University Medical Center, The Netherlands.
| | | |
Collapse
|
15
|
Fischbeck JA, Baier JM, Akella R, Hern-Anderson D, Schmidt CE. Genetic modification of alphaGal expression in xenogeneic endothelial cells yields a complex immunological response. TISSUE ENGINEERING 2001; 7:743-56. [PMID: 11749731 DOI: 10.1089/107632701753337690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The source of cells for tissue engineering applications remains a hurdle, predominantly for procedures in which there is insufficient time to harvest a patient's own cells. Animal cells are readily available, but undergo immune rejection. Rejection of animal (i.e., xenogeneic) tissue involves practically every component of the immune system. The initial phase, hyperacute rejection (HAR), involves natural xenoreactive antibodies and the complement system, and leads to endothelial cell lysis and rapid tissue destruction. The cell-surface epitope, galactose-alpha(1,3)-galactose (alphaGal), is presumed to play a key role in HAR. The later stage of immune response (delayed xenograft rejection or DXR), is mediated by immune cells such as monocytes. Carbohydrates are likely also involved in DXR, but their role in this phase of the immune response is less clear. A better understanding of all stages of xenogeneic immune rejection may make it feasible to create cell lines that are immune tolerant. In these studies, we have genetically modified bovine endothelial cells to study the roles of carbohydrates in immune rejection. Our studies suggest that one or more epitopes other than alphaGal may influence complement-mediated lysis. Furthermore, antibodies, as instigators in the complement response, and monocytes appear to recognize different cell surface epitopes.
Collapse
Affiliation(s)
- J A Fischbeck
- Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | | | | | | | | |
Collapse
|
16
|
Macchiarini P, Oriol R, Azimzadeh A, de Montpreville V, Wolf P, Dartevelle P. Characterization of a pig-to-goat orthotopic lung xenotransplantation model to study beyond hyperacute rejection. J Thorac Cardiovasc Surg 1999; 118:805-14. [PMID: 10534685 DOI: 10.1016/s0022-5223(99)70049-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND A pig-to-goat orthotopic lung xenograft model was developed to test whether depletion of goat xenoreactive antibodies against pig red blood cells would prolong pig lung xenograft survival. METHODS Adult goats with anti-pig xenoreactive antibodies underwent left pneumonectomy followed by orthotopic transplantation of pig left lung (group 1) or immunodepletion of their xenoreactive antibodies by extracorporeal right pig lung perfusion before transplantation without (group 2) or with (group 3) complete clampage of the right pulmonary artery. In group 4, goat left lungs were orthotopically transplanted into pigs and served as negative controls (pig serum does not have anti-goat xenoreactive antibodies). Each study group included 5 animals. Immunosuppression in surviving recipients included cyclosporine and azathioprine. RESULTS Group 1 recipients died 7 +/- 3 hours after xenograft reimplantation of severe pulmonary hypertension and dysfunction and vasogenic shock, with little evidence of histologic xenograft injury. Group 2 xenografts had a stable circulatory and respiratory function on reperfusion and survived 9 +/- 4 days. Group 3 animals also tolerated complete occlusion of the right pulmonary artery, and xenografts assured the total respiratory support for 4 +/- 1 days. After immunodepletion, goat serum showed no detectable titers of xenoreactive antibodies, which began to reappear by postoperative day 2, where xenografts showed histologic stigmata of acute (humoral and cellular-mediated) rejection that evolved to a complete xenograft necrose at death. Group 4 xenografts showed scattered features of acute rejection 5 +/- 1 days after the operation. CONCLUSIONS Pig left lung xenografts can provide prolonged and complete respiratory support after depletion of goat xenoreactive antibodies, but they ultimately necrose once recipient xenoreactive antibodies return to pretransplantation values.
Collapse
Affiliation(s)
- P Macchiarini
- Department of Thoracic and Vascular Surgery, and Heart-Lung Transplantation and Experimental Surgical Laboratory, Hôpital Marie-Lannelongue, Le Plessis Robinson, Paris-Sud University, France.
| | | | | | | | | | | |
Collapse
|
17
|
Charreau B, Ménoret S, Tesson L, Azimzadeh A, Audet M, Wolf P, Marquet R, Verbakel C, Ijzermans J, Cowan P, Pearse M, d’Apice A, Soulillou JP, Anegon I. Protection Against Hyperacute Xenograft Rejection of Transgenic Rat Hearts Expressing Human Decay Accelerating Factor (DAF) Transplanted into Primates. Mol Med 1999. [DOI: 10.1007/bf03402074] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
|
18
|
Meyer C, Wolf P, Romain N, Ravanat C, Roussi J, Beller JP, Imbs P, Chenard MP, Fabre M, Kieny R, Bonneau M, Drouet L, Cazenave JP, Soulillou JP, Azimzadeh A. Use of von Willebrand diseased kidney as donor in a pig-to-primate model of xenotransplantation. Transplantation 1999; 67:38-45. [PMID: 9921793 DOI: 10.1097/00007890-199901150-00006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND The coagulation process in hyperacute and delayed xenograft rejection is essential and depends upon platelet adhesion and aggregation. The initial binding of platelets to the damaged endothelium is due to the interaction of the platelet receptor glycoprotein Ib with von Willebrand factor (vWF), which is present on activated endothelial cells and bound to the subendothelial matrix. We hypothesized that the use of organs from animals with homozygous von Willebrand disease (vWD), severely deficient in vWF, might prevent the thrombosis encountered in delayed xenograft rejection. METHODS Ten baboons were treated by extracorporeal immunoadsorption of xenoreactive natural antibodies (XNA) through the donor pig liver to inhibit hyperacute rejection and received heterotopic vWD or control pig kidney xenografts. XNA levels, coagulation, and platelet activation markers were studied, and specimens of rejected kidneys were analyzed histologically. RESULTS Although XNA depletion was comparable in both groups, neither kidney function nor survival times of control (n=5) or vWD (n=5) porcine kidneys showed any difference. Platelet and coagulation activation was evidenced in both groups after surgery and at rejection time. Immunohistochemical analysis revealed a weak endothelial vWF immunostaining in the rejected vWD kidneys, whereas it was undetectable in the nongrafted vWD kidneys, suggesting the deposition of baboon plasma vWF on the porcine vessels. CONCLUSIONS The use of vWD organs did not improve the survival time of grafted kidneys in this xenotransplantation model. Further studies on the use of vWD organs, in association with other therapeutic approaches, such as complement inhibition, are nevertheless necessary to evaluate the usefulness of vWF deficiency as an adjunctive therapy to decrease the coagulation process during xenograft rejection.
Collapse
Affiliation(s)
- C Meyer
- Laboratoire de Chirurgie Expérimentale, Fondation Transplantation, Strasbourg, France.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Macchiarini P, Oriol R, Azimzadeh A, de Montpreville V, Rieben R, Bovin N, Mazmanian M, Dartevelle P. Evidence of human non-alpha-galactosyl antibodies involved in the hyperacute rejection of pig lungs and their removal by pig organ perfusion. J Thorac Cardiovasc Surg 1998; 116:831-43. [PMID: 9806390 DOI: 10.1016/s0022-5223(98)00447-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND Human natural xenoantibodies represent a major hurdle to the clinical application of pig lungs in transplantation by initiating hyperacute rejection within minutes to hours. OBJECTIVE The object was to compare pig organ perfusion and specific depletion of anti-alpha-galactosyl xenoantibodies for prevention of hyperacute rejection in the pig to human lung combination. METHODS Large White pig (20-25 kg) left lungs were removed and continuously ventilated and reperfused ex vivo either with (1) whole human blood previously perfused in situ through pig right lung (group I), liver (group II), or spleen (group III) or with (2) human plasma in vitro immunoabsorbed on columns containing alpha-galactosyl disaccharide (Gal-alpha-(1-3)Gal-beta-(CH2)3NH2; B disaccharide) (group IV). Each study group included 6 animals. RESULTS The in situ and in vitro preperfusions depleted anti-alpha-galactosyl xenoantibodies and all in situ perfused pig organs showed histologic signs of hyperacute rejection. After the ex vivo reperfusion, group I xenografts had a significantly (P < .001) longer functional and histologic survival than did xenografts in groups II, III, and IV. Human blood reperfusing group I xenografts had a significantly (P < 0.05) lower (1) decline of clotting factors and total circulating immunoglobulins, (2) total and membrane attack complex (C5b,6,7,8,9) complement activation, and (3) hemolysis. By Western blot analysis, the in situ lung preperfusion removed antibodies against non-alpha-galactosyl proteins of low molecular weight that were not eliminated by the alpha-galactosyl column. CONCLUSIONS Results demonstrate that specific depletion of anti-alpha-galactosyl antibodies alone incompletely protects pig lungs from hyperacute rejection. It is speculated that the more complete prevention of this rejection afforded by pig lung preperfusion relates to the removal of other, non-alpha-galactosyl antibodies.
Collapse
Affiliation(s)
- P Macchiarini
- Department of Thoracic and Vascular Surgery, Hôpital Marie-Lannelongue, Le Plessis Robinson, Paris-Sud University, France
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Azimzadeh A, Romain N, Vermot-Desroches C, Chenard MP, Meyer C, Wijdenes J, Hervé P, Cinqualbre J, Wolf P. Reactivity of anti-human adhesion molecules and von Willebrand factor monoclonal antibodies with pig antigens. Transplant Proc 1998; 30:2849-50. [PMID: 9745592 DOI: 10.1016/s0041-1345(98)00836-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- A Azimzadeh
- Laboratoire de Chirurgie Expérimentale, Fondation Transplantation, Strasbourg, France
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Auchincloss H. Literature update 1997, part 3. Xenotransplantation 1998; 5:164-7. [PMID: 9584830 DOI: 10.1111/j.1399-3089.1998.tb00022.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- H Auchincloss
- Transplantation Unit, Massachusetts General Hospital, Boston 02114, USA
| |
Collapse
|