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Sykes M, Sachs DH. Transplanting organs from pigs to humans. Sci Immunol 2020; 4:4/41/eaau6298. [PMID: 31676497 DOI: 10.1126/sciimmunol.aau6298] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 10/02/2019] [Indexed: 12/20/2022]
Abstract
The success of organ transplantation is limited by the complications of immunosuppression, by chronic rejection, and by the insufficient organ supply, and thousands of patients die every year while waiting for a transplant. With recent progress in xenotransplantation permitting porcine organ graft survival of months or even years in nonhuman primates, there is renewed interest in its potential to alleviate the organ shortage. Many of these advances are the result of our heightened capacity to modify pigs genetically, particularly with the development of CRISPR-Cas9-based gene editing methodologies. Although this approach allows the engineering of pig organs that are less prone to rejection, the clinical application of xenotransplantation will require the ability to avoid the ravages of a multifaceted attack on the immune system while preserving the capacity to protect both the recipient and the graft from infectious microorganisms. In this review, we will discuss the potential and limitations of these modifications and how the engineering of the graft can be leveraged to alter the host immune response so that all types of immune attack are avoided.
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Affiliation(s)
- Megan Sykes
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, NY, USA. .,Department of Microbiology and Immunology, Columbia University Medical Center, NY, USA.,Department of Surgery, Columbia University Medical Center, NY, USA
| | - David H Sachs
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, NY, USA.,Department of Surgery, Columbia University Medical Center, NY, USA
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2
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Ma Y, Zhao X, Jia J, Yang Y, Fan R, Lv M, Ding F, Wu J, Zhang J. Analysis of Protein Expression in Human Cells Cocultured with Porcine Peripheral Blood Mononuclear Cells. Intervirology 2019; 61:237-246. [PMID: 30889573 DOI: 10.1159/000495179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 10/15/2018] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Porcine endogenous retroviruses (PERV) involved in pig to human xenotransplantation have raised great concerns because of their ubiquitous nature in pigs and their ability of infecting human cells in vitro. Although no significant cytopathic effect attributed to PERV was evident on PERV-infected human embryonic kidney 293 (HEK293) cells, we did proteomic analysis to investigate the differences of protein profile in order to further characterize the effect of PERV infection. METHODS HEK293 cells were cocultured with porcine peripheral blood mononuclear cells (PBMCs). Protein profiles of PERV-infected and -noninfected HEK293 cells were analyzed by two-dimensional gel electrophoresis (2-DE). Protein spots with at least 1.5-fold alteration were identified by high-definition mass spectrometry (HDMS) analysis. Then real-time RT-PCR and Western blotting were performed to validate the proteomic results. RESULTS Differential analysis of PERV-infected and -noninfected HEK293 cells by 2-DE revealed ten differentially regulated proteins. The proteins identified by HDMS were involved in various cellular pathways including signal transduction, cell apoptosis, and protein synthesis. CONCLUSION The results of this study revealed differentially expressed proteins in HEK293 cells cocultured with porcine PBMCs and implied that these changes were probably induced by PERV infection. These results provide clues and potential links to understanding the molecular effect of the infection by human-tropic PERV.
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Affiliation(s)
- Yuyuan Ma
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Institute of Health Service and Transfusion Medicine, Academy of Military Medical Sciences, Beijing, China,
| | - Xiong Zhao
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Institute of Health Service and Transfusion Medicine, Academy of Military Medical Sciences, Beijing, China
| | - Junting Jia
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Institute of Health Service and Transfusion Medicine, Academy of Military Medical Sciences, Beijing, China.,Department of Blood Transfusion, Chinese PLA General Hospital, Beijing, China
| | - Yongxian Yang
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Institute of Health Service and Transfusion Medicine, Academy of Military Medical Sciences, Beijing, China
| | - Rui Fan
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Institute of Health Service and Transfusion Medicine, Academy of Military Medical Sciences, Beijing, China
| | - Maomin Lv
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Institute of Health Service and Transfusion Medicine, Academy of Military Medical Sciences, Beijing, China
| | - Fang Ding
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Institute of Health Service and Transfusion Medicine, Academy of Military Medical Sciences, Beijing, China
| | - Jianmin Wu
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Institute of Health Service and Transfusion Medicine, Academy of Military Medical Sciences, Beijing, China.,Guangxi Veterinary Research Institute, Nanning, China
| | - Jingang Zhang
- Beijing Key Laboratory of Blood Safety and Supply Technologies, Institute of Health Service and Transfusion Medicine, Academy of Military Medical Sciences, Beijing, China
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3
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Fishman JA. Infectious disease risks in xenotransplantation. Am J Transplant 2018; 18:1857-1864. [PMID: 29513380 DOI: 10.1111/ajt.14725] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 03/01/2018] [Accepted: 03/02/2018] [Indexed: 01/25/2023]
Abstract
Hurdles exist to clinical xenotransplantation including potential infectious transmission from nonhuman species to xenograft recipients. In anticipation of clinical trials of xenotransplantation, the associated infectious risks have been investigated. Swine and immunocompromised humans share some potential pathogens. Swine herpesviruses including porcine cytomegalovirus (PCMV) and porcine lymphotropic herpesvirus (PLHV) are largely species-specific and do not, generally, infect human cells. Human cellular receptors exist for porcine endogenous retrovirus (PERV), which infects certain human-derived cell lines in vitro. PERV-inactivated pigs have been produced recently. Human infection due to PERV has not been described. A screening paradigm can be applied to exclude potential human pathogens from "designated pathogen free" breeding colonies. Various microbiological assays have been developed for screening and diagnosis including antibody-based tests and qualitative and quantitative molecular assays for viruses. Additional assays may be required to diagnose pig-specific organisms in human xenograft recipients. Significant progress has been made in the evaluation of the potential infectious risks of clinical xenotransplantation. Infectious risk would be amplified by intensive immunosuppression. The available data suggest that risks of xenotransplant-associated recipient infection are manageable and that clinical trials can be performed safely. Possible infectious risks of xenotransplantation to the community at large are undefined but merit consideration.
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Affiliation(s)
- Jay A Fishman
- Infectious Disease Division and MGH Transplant Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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4
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Denner J, Scobie L, Schuurman HJ. Is it currently possible to evaluate the risk posed by PERVs for clinical xenotransplantation? Xenotransplantation 2018; 25:e12403. [DOI: 10.1111/xen.12403] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 04/13/2018] [Indexed: 12/23/2022]
Affiliation(s)
| | - Linda Scobie
- School of Health and Life Sciences; Glasgow Caledonian University; Glasgow UK
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5
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Denner J. Why was PERV not transmitted during preclinical and clinical xenotransplantation trials and after inoculation of animals? Retrovirology 2018; 15:28. [PMID: 29609635 PMCID: PMC5879552 DOI: 10.1186/s12977-018-0411-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/22/2018] [Indexed: 01/27/2023] Open
Abstract
Porcine endogenous retroviruses (PERVs) are present in the genome of all pigs, they infect certain human cells and therefore pose a special risk for xenotransplantation using pig cells, tissues and organs. Xenotransplantation is being developed in order to alleviate the reduced availability of human organs. Despite the fact that PERVs are able to infect certain human cells and cells from other species, transmission of PERVs has not been observed when animals (including non-human primates) were inoculated with PERV preparations or during preclinical xenotransplantations. The data indicate that PERVs were not transmitted because they were not released from the transplant or were inhibited by intracellular restriction factors and innate immunity in the recipient. In a single study in guinea pigs, a transient PERV infection and anti-PERV antibodies were described, indicating that in this case at least, the immune system may also have been involved.
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Affiliation(s)
- Joachim Denner
- Robert Koch Institute, Nordufer 20, 13353, Berlin, Germany.
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6
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Cooper DKC, Cowan P, Fishman JA, Hering BJ, Mohiuddin MM, Pierson RN, Sachs DH, Schuurman HJ, Dennis JU, Tönjes RR. Joint FDA‐IXA Symposium, September 20, 2017. Xenotransplantation 2017; 24. [PMID: 29193342 DOI: 10.1111/xen.12365] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Peter Cowan
- Immunology Research Centre, St Vincent's Hospital, Melbourne, Victoria, Australia
| | - Jay A Fishman
- Infectious Disease Division and MGH Transplant Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Bernhard J Hering
- Department of Surgery, University of Minnesota, Minneapolis, MN, USA
| | - Muhammad M Mohiuddin
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Richard N Pierson
- Department of Surgery, University of Maryland School of Medicine, Baltimore VA Medical Center, Baltimore, MD, USA
| | - David H Sachs
- Columbia University Medical Center, New York City, NY, USA.,Harvard Medical School and Massachusetts General Hospital, Boston, MA, USA
| | | | - John U Dennis
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ralf R Tönjes
- Paul-Ehrlich-Institut, Federal Institute for Vaccines and Biomedicines, Division of Medical Biotechnology, Langen, Germany
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7
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Kim N, Choi J, Kim S, Gwon YD, Cho Y, Yang JM, Oh YK, Kim YB. Transmission of Porcine Endogenous Retrovirus Produced from Different Recipient Cells In Vivo. PLoS One 2016; 11:e0165156. [PMID: 27832080 PMCID: PMC5104465 DOI: 10.1371/journal.pone.0165156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/29/2016] [Indexed: 12/04/2022] Open
Abstract
Humanized pigs have been developed to reduce the incidence of immune rejection in xenotransplantation, but significant concerns remain, such as transmission of viral zoonosis. Porcine endogenous retroviruses (PERV), which exist in the genome of pigs, are produced as infectious virions from all porcine cells and cause zoonosis. Here, we examined the possibility of zoonosis of hosts under conditions of immune suppression or xenotransplantation of cells producing host-adapted viruses. Upon transplantation of PERV-producing porcine cells into mice, no transmission of PERV was detected, whereas, transmission of PERV from mice transplanted with mouse-adapted PERV-producing cells was detected. In addition, the frequency of PERV transmission was increased in CsA treated mice transplanted with PERV-producing murine cells, compared with PERV-producing porcine cells. Transmission of PERV to host animals did not affect weight but immune responses, in particular, the number of T cells from PERV-transmitted mice, were notably reduced. The observed risk of PERV zoonosis highlights the requirement for thorough evaluation of viral zoonosis under particular host conditions, such as immunosuppressive treatment and transplantation with host-adapted virus-producing cells.
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Affiliation(s)
- Nayoung Kim
- Department of Life Sciences, Sogang University, Seoul, Republic of Korea
| | - Jiwon Choi
- Department of Bio-industrial Technologies, Konkuk University, Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| | - Sehyun Kim
- Department of Bio-industrial Technologies, Konkuk University, Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| | - Yong-Dae Gwon
- Department of Bio-industrial Technologies, Konkuk University, Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| | - Yeondong Cho
- Department of Bio-industrial Technologies, Konkuk University, Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
| | - Jae Myung Yang
- Department of Life Sciences, Sogang University, Seoul, Republic of Korea
| | - Yu-Kyoung Oh
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Young bong Kim
- Department of Bio-industrial Technologies, Konkuk University, Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea
- * E-mail:
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8
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Han B, Shi XL, Zhang Y, Gu ZZ, Yuan XW, Ren HZ, Qiu Y, Ding YT. No transmission of porcine endogenous retrovirus in an acute liver failure model treated by a novel hybrid bioartificial liver containing porcine hepatocytes. Hepatobiliary Pancreat Dis Int 2015; 14:492-501. [PMID: 26459725 DOI: 10.1016/s1499-3872(15)60401-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND A novel hybrid bioartificial liver (HBAL) was constructed using an anionic resin adsorption column and a multi-layer flat-plate bioreactor containing porcine hepatocytes co-cultured with bone marrow mesenchymal stem cells (MSCs). This study aimed to evaluate the microbiological safety of the HBAL by detecting the transmission of porcine endogenous retroviruses (PERVs) into canines with acute liver failure (ALF) undergoing HBAL. METHODS Eight dogs with ALF received a 6-hour HBAL treatment on the first day after the modeling by D-galactosamine administration. The plasma in the HBAL and the whole blood in the dogs were collected for PERV detection at regular intervals until one year later when the dogs were sacrificed to retrieve the tissues of several organs for immunohistochemistry and Western blotting for the investigation of PERV capsid protein gag p30 in the tissue. Furthermore, HEK293 cells were incubated to determine the in vitro infectivity. RESULTS PERV RNA and reverse transcriptase activity were observed in the plasma of circuit 3, suggesting that PERV particles released in circuit 3. No positive PERV RNA and reverse transcriptase activity were detected in other plasma. No HEK293 cells were infected by the plasma in vitro. In addition, all PERV-related analyses in peripheral blood mononuclear cells and tissues were negative. CONCLUSION No transmission of PERVs into ALF canines suggested a reliable microbiological safety of HBAL based on porcine hepatocytes.
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Affiliation(s)
- Bing Han
- Department of Hepatobiliary Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China.
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Kimsa-Dudek M, Strzalka-Mrozik B, Kimsa MW, Blecharz I, Gola J, Skowronek B, Janiszewski A, Lipinski D, Zeyland J, Szalata M, Slomski R, Mazurek U. Screening pigs for xenotransplantation: expression of porcine endogenous retroviruses in transgenic pig skin. Transgenic Res 2015; 24:529-36. [PMID: 25812516 DOI: 10.1007/s11248-015-9871-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 03/23/2015] [Indexed: 01/30/2023]
Abstract
Pigs seem to be the answer to worldwide organ donor shortage. Porcine skin may also be applied as a dressing for severe burns. Genetic modifications of donor animals enable reduction of immune response, which prolongs xenograft survival as temporary biological dressing and allows achieving resistance against xenograft rejection. The risk posed by porcine endogenous retroviruses (PERVs) cannot be eliminated by breeding animals under specific-pathogen-free conditions and so all recipients of porcine graft will be exposed to PERVs. Therefore our study has been focused on the assessment of PERV DNA and mRNA level in skin samples of transgenic pigs generated for xenotransplantation. Porcine skin fragments were obtained from 3- to 6-month-old non-transgenic and transgenic Polish Landrace pigs. Transgenic pigs were produced by pronuclear DNA microinjection and were developed to express the human α-galactosidase and the human α-1,2-fucosyltransferase gene. The copy numbers of PERV DNA and RNA were evaluated using real-time Q-PCR and QRT-PCR. Comparative analysis of all PERV subtypes revealed that PERV-A is the main subtype of PERVs in analyzed skin samples. There was no significantly different copy number of PERV-A, PERV-B and PERV-C between non-transgenic pigs, pigs with the human α-galactosidase and pigs expressing the human α-1,2-fucosyltransferase gene, except of PERV-C DNA. It brings the conclusion, that transgenesis process exerts no influence on PERVs transinfection. That is another step forward in the development of pig skin xenografts as burn wounds dressing.
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Affiliation(s)
- Magdalena Kimsa-Dudek
- Department of Food and Nutrition, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Jednosci 8, 41-200, Sosnowiec, Poland,
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10
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Griesemer A, Yamada K, Sykes M. Xenotransplantation: immunological hurdles and progress toward tolerance. Immunol Rev 2015; 258:241-58. [PMID: 24517437 DOI: 10.1111/imr.12152] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The discrepancy between organ need and organ availability represents one of the major limitations in the field of transplantation. One possible solution to this problem is xenotransplantation. Research in this field has identified several obstacles that have so far prevented the successful development of clinical xenotransplantation protocols. The main immunologic barriers include strong T-cell and B-cell responses to solid organ and cellular xenografts. In addition, components of the innate immune system can mediate xenograft rejection. Here, we review these immunologic and physiologic barriers and describe some of the strategies that we and others have developed to overcome them. We also describe the development of two strategies to induce tolerance across the xenogeneic barrier, namely thymus transplantation and mixed chimerism, from their inception in rodent models through their current progress in preclinical large animal models. We believe that the addition of further beneficial transgenes to Gal knockout swine, combined with new therapies such as Treg administration, will allow for successful clinical application of xenotransplantation.
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Affiliation(s)
- Adam Griesemer
- Columbia Center for Translational Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA
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11
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De Salvatore S, Segreto A, Chiusaroli A, Congiu S, Bizzarri F. Role of xenotransplantation in cardiac transplantation. J Card Surg 2014; 30:111-6. [PMID: 25345720 DOI: 10.1111/jocs.12454] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This review will discuss the history and development of the field of genetic modification, up to the most recent scientific discoveries, and will also consider the current uses of genetic therapy.
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Affiliation(s)
- Sergio De Salvatore
- Department of Science and Medical-Surgical Biotechnologies, Cardiac Surgery Unit, Universita' degli Studi di Roma "Sapienza", Latina, Italy
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12
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Porcine endogenous retroviruses in xenotransplantation--molecular aspects. Viruses 2014; 6:2062-83. [PMID: 24828841 PMCID: PMC4036542 DOI: 10.3390/v6052062] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/15/2014] [Accepted: 04/26/2014] [Indexed: 02/06/2023] Open
Abstract
In the context of the shortage of organs and other tissues for use in human transplantation, xenotransplantation procedures with material taken from pigs have come under increased consideration. However, there are unclear consequences of the potential transmission of porcine pathogens to humans. Of particular concern are porcine endogenous retroviruses (PERVs). Three subtypes of PERV have been identified, of which PERV-A and PERV-B have the ability to infect human cells in vitro. The PERV-C subtype does not show this ability but recombinant PERV-A/C forms have demonstrated infectivity in human cells. In view of the risk presented by these observations, the International Xenotransplantation Association recently indicated the existence of four strategies to prevent transmission of PERVs. This article focuses on the molecular aspects of PERV infection in xenotransplantation and reviews the techniques available for the detection of PERV DNA, RNA, reverse transcriptase activity and proteins, and anti-PERV antibodies to enable carrying out these recommendations. These methods could be used to evaluate the risk of PERV transmission in human recipients, enhance the effectiveness and reliability of monitoring procedures, and stimulate discussion on the development of improved, more sensitive methods for the detection of PERVs in the future.
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Microbiological safety of a novel bio-artificial liver support system based on porcine hepatocytes: a experimental study. Eur J Med Res 2012; 17:13. [PMID: 22632261 PMCID: PMC3419623 DOI: 10.1186/2047-783x-17-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 05/25/2012] [Indexed: 12/11/2022] Open
Abstract
Background Our institute has developed a novel bio-artificial liver (BAL) support system, based on a multi-layer radial-flow bioreactor carrying porcine hepatocytes and mesenchymal stem cells. It has been shown that porcine hepatocytes are capable of carrying infectious porcine endogenous retroviruses (PERVs) into human cells, thus the microbiological safety of any such system must be confirmed before clinical trials can be performed. In this study, we focused on assessing the status of PERV infection in beagles treated with the novel BAL. Methods Five normal beagles were treated with the novel BAL for 6 hours. The study was conducted for 6 months, during which plasma was collected from the BAL and whole blood from the beagles at regular intervals. DNA and RNA in both the collected peripheral blood mononuclear cells (PBMCs) and plasma samples were extracted for conventional PCR and reverse transcriptase (RT)-PCR with PERV-specific primers and the porcine-specific primer Sus scrofa cytochrome B. Meanwhile, the RT activity and the in vitro infectivity of the plasma were measured. Results Positive PERV RNA and RT activity were detected only in the plasma samples taken from the third circuit of the BAL system. All other samples including PBMCs and other plasma samples were negative for PERV RNA, PERV DNA, and RT activity. In the in vitro infection experiment, no infection was found in HEK293 cells treated with plasma. Conclusions No infective PERV was detected in the experimental animals, thus the novel BAL had a reliable microbiological safety profile.
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14
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Denner J, Tönjes RR. Infection barriers to successful xenotransplantation focusing on porcine endogenous retroviruses. Clin Microbiol Rev 2012; 25:318-43. [PMID: 22491774 PMCID: PMC3346299 DOI: 10.1128/cmr.05011-11] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Xenotransplantation may be a solution to overcome the shortage of organs for the treatment of patients with organ failure, but it may be associated with the transmission of porcine microorganisms and the development of xenozoonoses. Whereas most microorganisms may be eliminated by pathogen-free breeding of the donor animals, porcine endogenous retroviruses (PERVs) cannot be eliminated, since these are integrated into the genomes of all pigs. Human-tropic PERV-A and -B are present in all pigs and are able to infect human cells. Infection of ecotropic PERV-C is limited to pig cells. PERVs may adapt to host cells by varying the number of LTR-binding transcription factor binding sites. Like all retroviruses, they may induce tumors and/or immunodeficiencies. To date, all experimental, preclinical, and clinical xenotransplantations using pig cells, tissues, and organs have not shown transmission of PERV. Highly sensitive and specific methods have been developed to analyze the PERV status of donor pigs and to monitor recipients for PERV infection. Strategies have been developed to prevent PERV transmission, including selection of PERV-C-negative, low-producer pigs, generation of an effective vaccine, selection of effective antiretrovirals, and generation of animals transgenic for a PERV-specific short hairpin RNA inhibiting PERV expression by RNA interference.
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15
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Duan K, Zhang B, Zhang W, Zhao Y, Qu Y, Sun C, Zhao Y. Efficient peripheral construction of functional human regulatory CD4(+)CD25(high)Foxp3(+) T cells in NOD/SCID mice grafted with fetal human thymus/liver tissues and CD34(+) cells. Transpl Immunol 2011; 25:173-9. [PMID: 21856420 DOI: 10.1016/j.trim.2011.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 07/27/2011] [Accepted: 08/04/2011] [Indexed: 10/17/2022]
Abstract
Regulatory T cells, especially CD4(+)CD25(+) regulatory T cells are critical regulators of immune tolerance in humans and mice. Mice with humanized immunity have been developed by various transplantation strategies of human tissues or cells related to immunity, which are being extensively applied in biomedical research. However, it is unclear whether human CD4(+)CD25(+) regulatory T cells can normally develop in human thymic grafts and efficiently populate in the periphery in NOD/SCID mouse recipients. In human thymic grafts, high percentage of mature human CD4(+)CD25(high) regulatory T cells was detected. Human CD4(+)CD25(+) regulatory T cells maturing in fetal human thymus grafts could subsequently output to the periphery of NOD/SCID mouse recipients. Importantly, these cells exhibited Foxp3(+)CD45RO(+)CTLA4(+)CD127(-) phenotype, similarly to those in healthy individuals. In addition, human CD4(+)CD25(+) regulatory T cells maturing in human thymic grafts suppressed proliferative response of CD4(+)CD25(-) T cells to allogeneic antigens, though the peripheral CD4(+)CD25(+) regulatory T cells in fetal human thymus-grafted NOD/SCID mice showed somewhat decreased immunosuppressive ability compared with normal CD4(+)CD25(+) regulatory T cells. Thus, this humanized animal model is suitable for examining development and function of human CD4(+)CD25(+) regulatory T cells in vivo.
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Affiliation(s)
- Kaizhong Duan
- Transplantation Biology Research Division, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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16
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Garkavenko O, Dieckhoff B, Wynyard S, Denner J, Elliott RB, Tan PL, Croxson MC. Absence of transmission of potentially xenotic viruses in a prospective pig to primate islet xenotransplantation study. J Med Virol 2008; 80:2046-52. [PMID: 18814261 DOI: 10.1002/jmv.21272] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Shortage of human donor organs for transplantation has prompted usage of animals as an alternative donor source. Pigs are the most acceptable candidate animals but issues of xenozoonoses remain. Despite careful monitoring of designated pathogen free pigs there is still a risk that their tissues may carry infectious agents. Thus xenotransplantation requires extensive pre-clinical study on safety of the graft especially for those viruses that are either potentially oncogenic and/or immunosuppressive, or can establish persistent infection. A prospective pig-to-primate islet xenotransplantation study was performed which includes monitoring for potentially xenotic viruses namely porcine endogenous retrovirus (PERV), porcine cytomegalovirus (PCMV), porcine lymphotropic herpesvirus (PLHV), and porcine circovirus (PCV) using both molecular diagnostic-PCR and RT-PCR and serology methods. There was no evidence of pig virus transmission into primate recipients. This preclinical study underlines the information concerning viral safety of islet cell xenograft in pig-to-primate xenotransplantation.
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Affiliation(s)
- Olga Garkavenko
- Molecular Diagnostic Laboratory, Living Cell Technologies NZ Ltd, Auckland, New Zealand.
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17
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Absence of replication of porcine endogenous retrovirus and porcine lymphotropic herpesvirus type 1 with prolonged pig cell microchimerism after pig-to-baboon xenotransplantation. J Virol 2008; 82:12441-8. [PMID: 18829759 DOI: 10.1128/jvi.01278-08] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Porcine endogenous retrovirus (PERV), porcine cytomegalovirus (PCMV), and porcine lymphotropic herpesvirus (PLHV) are common porcine viruses that may be activated with immunosuppression for xenotransplantation. Studies of viral replication or transmission are possible due to prolonged survival of xenografts in baboon recipients from human decay-accelerating factor transgenic or alpha-1,3-galactosyltransferase gene knockout miniature swine. Ten baboons underwent xenotransplantation with transgenic pig organs. Graft survival was 32 to 179 days. Recipient serial samples of peripheral blood mononuclear cells (PBMC) and plasma were analyzed for PCMV, PERV, and PLHV-1 nucleic acids and viral replication using quantitative PCR assays. The PBMC contained PERV proviral DNA in 10 animals, PLHV-1 DNA in 6, and PCMV in 2. PERV RNA was not detected in any PBMC or serum samples. Plasma PLHV-1 DNA was detected in one animal. Pig cell microchimerism (pig major histocompatibility complex class I and pig mitochondrial cytochrome c oxidase subunit II sequences) was present in all recipients with detectable PERV or PLHV-1 (85.5%). Productive infection of PERV or PLHV-1 could not be demonstrated. The PLHV-1 viral load did not increase in serum over time, despite prolonged graft survival and pig cell microchimerism. There was no association of viral loads with the nature of exogenous immune suppression. In conclusion, PERV provirus and PLHV-1 DNA were detected in baboons following porcine xenotransplantation. Viral detection appeared to be due to persistent pig cell microchimerism. There was no evidence of productive infection in recipient baboons for up to 6 months of xenograft function.
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Zhang B, Duan Z, Zhao Y. Mouse models with human immunity and their application in biomedical research. J Cell Mol Med 2008; 13:1043-58. [PMID: 18419795 PMCID: PMC4496103 DOI: 10.1111/j.1582-4934.2008.00347.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Biomedical research in human beings is largely restricted to in vitro studies that lack complexity of a living organism. To overcome this limitation, humanized mouse models are developed based on immunodeficient characteristics of severe combined immunodeficiency (SCID) or recombination activating gene (Rag)(null) mice, which can accept xenografts. Peripheral constitution of human immunity in SCID or Rag(null) mice has been achieved by transplantation of mature human immune cells, foetal human thymus, bone marrow, liver tissues, lymph nodes or a combination of these, although efficiency needs to be improved. These mouse models with constituted human immunity (defined as humanized mice in the present text) have been widely used to investigate the basic principles of human immunobiology as well as complex pathomechanisms and potential therapies of human diseases. Here, elements of an ideal humanized mouse model are highlighted including genetic and non-genetic modification of recipient mice, transplantation strategies and proposals to improve engraftments. The applications of the humanized mice to study the development and response of human immune cells, human autoimmune diseases, virus infections, transplantation biology and tumour biology are reviewed as well.
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Affiliation(s)
- Baojun Zhang
- Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Louz D, Bergmans HE, Loos BP, Hoeben RC. Reappraisal of biosafety risks posed by PERVs in xenotransplantation. Rev Med Virol 2008; 18:53-65. [PMID: 17987669 DOI: 10.1002/rmv.559] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Donor materials of porcine origin could potentially provide an alternative source of cells, tissues or whole organs for transplantation to humans, but is hampered by the health risk posed by infection with porcine viruses. Although pigs can be bred in such a way that all known exogenous microorganisms are eliminated, this is not feasible for all endogenous pathogens, such as the porcine endogenous retroviruses (PERVs) which are present in the germline of pigs as proviruses. Upon transplantation, PERV proviruses would be transferred to the human recipient along with the xenograft. If xenotransplantation stimulates or facilitates replication of PERVs in the new hosts, a risk exists for adaptation of the virus to humans and subsequent spread of these viruses. In a worst-case scenario, this might result in the emergence of a new viral disease. Although the concerns for disease potential of PERVs are easing, only limited pre-clinical and clinical data are available. Small-scale, well-designed and carefully controlled clinical trials would provide more evidence on the safety of this approach and allow a better appreciation of the risks involved. It is therefore important to have a framework of protective measures and monitoring protocols in place to facilitate such initially small scale clinical trials. This framework will raise ethical and social considerations regarding acceptability.
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Affiliation(s)
- Derrick Louz
- GMO office, Substances Expertise Centre of the National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
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20
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Yang YG, Sykes M. Xenotransplantation: current status and a perspective on the future. Nat Rev Immunol 2007; 7:519-31. [PMID: 17571072 DOI: 10.1038/nri2099] [Citation(s) in RCA: 237] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Xenotransplantation using pigs as the transplant source has the potential to resolve the severe shortage of human organ donors. Although the development of relatively non-toxic immunosuppressive or tolerance-inducing regimens will be required to justify clinical trials using pig organs, recent advances in our understanding of the biology of xenograft rejection and zoonotic infections, and the generation of alpha1,3-galactosyltransferase-deficient pigs have moved this approach closer to clinical application. This Review highlights the major obstacles impeding the translation of xenotransplantation into clinical therapies and the potential solutions, providing a perspective on the future of clinical xenotransplantation.
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Affiliation(s)
- Yong-Guang Yang
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02129, USA
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Levy MF, Argaw T, Wilson CA, Brooks J, Sandstrom P, Merks H, Logan J, Klintmalm G. No evidence of PERV infection in healthcare workers exposed to transgenic porcine liver extracorporeal support. Xenotransplantation 2007; 14:309-15. [PMID: 17669172 DOI: 10.1111/j.1399-3089.2007.00408.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Clinical xenotransplantation holds great promise by providing one solution to the shortage of human organs for transplantation, while also posing a potential public health threat by facilitating transmission of infectious disease from source animals to humans. One potential vector for infectious disease transmission is healthcare workers (HCW) who are involved in administering xenotransplantation procedures. METHODS In this study, we studied 49 healthcare workers involved in the care of two subjects who participated in a study of porcine liver perfusion as treatment of fulminant hepatic failure. We looked for serologic and virologic evidence of transmission of porcine endogenous retrovirus, and found that HCW had no evidence of infection. CONCLUSIONS Results of our survey demonstrate that application of standard precautions may be sufficient to prevent transmission of porcine endogenous retrovirus, an agent of concern in ex vivo xenotransplantation products.
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Affiliation(s)
- Marlon F Levy
- Baylor All Saints Medical Center, Fort Worth, TX 76104, USA.
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22
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Sykes M, Pierson RN, O'Connell P, D'Apice A, Cowan P, Cozzi E, Dorling A, Hering B, Leventhal J, Soulillou JP. Reply to 'Critics slam Russian trial to test pig pancreas for diabetes'. Nat Med 2007; 13:662-3. [PMID: 17554327 DOI: 10.1038/nm0607-662] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Vajta G, Zhang Y, Macháty Z. Somatic cell nuclear transfer in pigs: recent achievements and future possibilities. Reprod Fertil Dev 2007; 19:403-23. [PMID: 17257528 DOI: 10.1071/rd06089] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Accepted: 10/24/2006] [Indexed: 12/11/2022] Open
Abstract
During the past 6 years, considerable advancement has been achieved in experimental embryology of pigs. This process was mainly generated by the rapidly increasing need for transgenic pigs for biomedical research purposes, both for future xenotransplantation to replace damaged human organs or tissues, and for creating authentic animal models for human diseases to study aetiology, pathogenesis and possible therapy. Theoretically, among various possibilities, an established somatic cell nuclear transfer system with genetically engineered donor cells seems to be an efficient and reliable approach to achieve this goal. However, as the result of unfortunate coincidence of known and unknown factors, porcine embryology had been a handicapped branch of reproductive research in domestic animals and a very intensive and focused research was required to eliminate or minimise this handicap. This review summarises recent achievements both in the background technologies (maturation, activation, embryo culture) and the actual performance of the nuclear replacement. Recent simplified methods for in vivo development after embryo transfer are also discussed. Finally, several fields of potential application for human medical purposes are discussed. The authors conclude that although in this early phase of research no direct evidence can be provided about the practical use of transgenic pigs produced by somatic cell nuclear transfer as organ donors or disease models, the future chances even in medium term are good, and at least proportional with the efforts and sums that are invested into this research area worldwide.
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Affiliation(s)
- Gábor Vajta
- Population Genetics and Embryology, Department of Genetics and Biotechnology, Danish Institute of Agricultural Sciences, DK-8830 Tjele, Denmark.
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Martina Y, Marcucci KT, Cherqui S, Szabo A, Drysdale T, Srinivisan U, Wilson CA, Patience C, Salomon DR. Mice transgenic for a human porcine endogenous retrovirus receptor are susceptible to productive viral infection. J Virol 2006; 80:3135-46. [PMID: 16537582 PMCID: PMC1440412 DOI: 10.1128/jvi.80.7.3135-3146.2006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Porcine endogenous retrovirus (PERV) is considered one of the major risks in xenotransplantation. No valid animal model has been established to evaluate the risks associated with PERV transmission to human patients by pig tissue xenotransplantation or to study the potential pathogenesis associated with PERV infection. In previous work we isolated two genes encoding functional human PERV receptors and proved that introduction of these into mouse fibroblasts allowed the normally nonpermissive mouse cells to become productively infected (T. A. Ericsson, Y. Takeuchi, C. Templin, G. Quinn, S. F. Farhadian, J. C. Wood, B. A. Oldmixon, K. M. Suling, J. K. Ishii, Y. Kitagawa, T. Miyazawa, D. R. Salomon, R. A. Weiss, and C. Patience, Proc. Natl. Acad. Sci. USA 100:6759-6764, 2003). In the present study we created mice transgenic for human PERV-A receptor 2 (HuPAR-2). After inoculation of transgenic animals with infectious PERV supernatants, viral DNA and RNA were detected at multiple time points, indicating productive replication. This establishes the role of HuPAR-2 in PERV infection in vivo; in addition, these transgenic mice represent a new model for determining the risk of PERV transmission and potential pathogenesis. These mice also create a unique opportunity to study the immune response to PERV infection and test potential therapeutic or preventative modalities.
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MESH Headings
- Animals
- Animals, Newborn
- Blotting, Western
- Cell Line
- DNA, Viral/analysis
- DNA, Viral/genetics
- DNA, Viral/isolation & purification
- Endogenous Retroviruses/genetics
- Endogenous Retroviruses/isolation & purification
- Endogenous Retroviruses/physiology
- Humans
- Mice
- Mice, Transgenic
- Microscopy, Confocal
- NIH 3T3 Cells
- RNA, Viral/analysis
- RNA, Viral/genetics
- RNA, Viral/isolation & purification
- Receptors, Virus/metabolism
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/isolation & purification
- Recombinant Proteins/metabolism
- Retroviridae Infections/transmission
- Retroviridae Infections/virology
- Reverse Transcriptase Polymerase Chain Reaction
- Swine/virology
- Time Factors
- Transgenes
- Virus Replication
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Affiliation(s)
- Y Martina
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
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Current World Literature. Curr Opin Organ Transplant 2006. [DOI: 10.1097/01.mot.0000218938.96009.b4] [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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Schmidt P, Forsman A, Andersson G, Blomberg J, Korsgren O. Pig islet xenotransplantation: activation of porcine endogenous retrovirus in the immediate post-transplantation period. Xenotransplantation 2005; 12:450-6. [PMID: 16202068 DOI: 10.1111/j.1399-3089.2005.00244.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Porcine endogenous retroviruses (PERV) are considered as the main infectious barrier in islet xenotransplantation. PERV has been shown to infect, but not to cause symptomatic disease in mice after islet transplantation. In vivo activation of PERV have so far not been examined. Expression of PERV was examined in adult and fetal porcine islets with or without the presence of known retroviral inducers or after transplantation to rats. METHODS Isolated adult and fetal porcine islets were cultured under normal conditions or in the presence of dexamethasone or 5-azacytidine and 5-iodo-2-deoxyuridine. PERV mRNA content was analyzed by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and culture supernatants were analyzed for the presence of retroviral RT. Also, fetal islets were transplanted under the kidney capsule of immunocompetent or nude athymic rats. Expression of PERV mRNA in the grafts was evaluated by real-time quantitative RT-PCR. Infiltration of immunocompetent cells were evaluated by immunohistochemistry. RESULTS Both fetal and adult islets in culture produced small or even undetectable amounts of PERV mRNA and retroviral RT. PERV expression was not enhanced by retroviral inducers. In contrast, activation of PERV expression was observed the first day after transplantation of fetal islet-like cell clusters in both athymic and normal rats. PERV expression peaked after 1 to 3 days and was then rapidly returned to background levels. PERV expression neither correlated with the innate immune response seen in athymic rats nor with the specific process of rejection in normal rats. CONCLUSION Both fetal and adult islets produce low amounts of PERV mRNA in culture. After transplantation PERV expression is induced, seemingly independent of both the unspecific inflammatory response and the specific T-cell-mediated rejection process. It is speculated that PERV expression is correlated with the level of hypoxia in the islet xenograft.
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Affiliation(s)
- Peter Schmidt
- The Rudbeck Laboratory, Division of Clinical Immunology, Uppsala University, Uppsala, Sweden.
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