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Lange A, Medugorac I, Ali A, Kessler B, Kurome M, Zakhartchenko V, Hammer SE, Hauser A, Denner J, Dobenecker B, Wess G, Tan PLJ, Garkavenko O, Reichart B, Wolf E, Kemter E. Genetic diversity, growth and heart function of Auckland Island pigs, a potential source for organ xenotransplantation. Xenotransplantation 2024; 31:e12858. [PMID: 38646921 DOI: 10.1111/xen.12858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/23/2024] [Accepted: 03/28/2024] [Indexed: 04/23/2024]
Abstract
One of the prerequisites for successful organ xenotransplantation is a reasonable size match between the porcine organ and the recipient's organ to be replaced. Therefore, the selection of a suitable genetic background of source pigs is important. In this study, we investigated body and organ growth, cardiac function, and genetic diversity of a colony of Auckland Island pigs established at the Center for Innovative Medical Models (CiMM), LMU Munich. Male and female Auckland Island pig kidney cells (selected to be free of porcine endogenous retrovirus C) were imported from New Zealand, and founder animals were established by somatic cell nuclear transfer (SCNT). Morphologically, Auckland Island pigs have smaller body stature compared to many domestic pig breeds, rendering their organ dimensions well-suited for human transplantation. Furthermore, echocardiography assessments of Auckland Island pig hearts indicated normal structure and functioning across various age groups throughout the study. Single nucleotide polymorphism (SNP) analysis revealed higher runs of homozygosity (ROH) in Auckland Island pigs compared to other domestic pig breeds and demonstrated that the entire locus coding the swine leukocyte antigens (SLAs) was homozygous. Based on these findings, Auckland Island pigs represent a promising genetic background for organ xenotransplantation.
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Affiliation(s)
- Andreas Lange
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, Munich, Germany
| | - Ivica Medugorac
- Population Genomics Group, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Asghar Ali
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, Munich, Germany
| | - Barbara Kessler
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, Munich, Germany
| | - Mayuko Kurome
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, Munich, Germany
| | - Valeri Zakhartchenko
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, Munich, Germany
| | - Sabine E Hammer
- Institute of Immunology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Andreas Hauser
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Joachim Denner
- Institute of Virology, Free University of Berlin, Berlin, Germany
| | - Britta Dobenecker
- Chair for Animal Nutrition, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Gerhard Wess
- Clinic of Small Animal Medicine, Center for Clinical Veterinary Medicine, LMU Munich, Munich, Germany
| | | | | | - Bruno Reichart
- Walter-Brendel-Center for Experimental Medicine, LMU Munich, Munich, Germany
| | - Eckhard Wolf
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, Munich, Germany
- Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU Munich, Munich, Germany
| | - Elisabeth Kemter
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, Munich, Germany
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2
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Ali A, Kemter E, Wolf E. Advances in Organ and Tissue Xenotransplantation. Annu Rev Anim Biosci 2024; 12:369-390. [PMID: 37906838 DOI: 10.1146/annurev-animal-021122-102606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
End-stage organ failure can result from various preexisting conditions and occurs in patients of all ages, and organ transplantation remains its only treatment. In recent years, extensive research has been done to explore the possibility of transplanting animal organs into humans, a process referred to as xenotransplantation. Due to their matching organ sizes and other anatomical and physiological similarities with humans, pigs are the preferred organ donor species. Organ rejection due to host immune response and possible interspecies infectious pathogen transmission have been the biggest hurdles to xenotransplantation's success. Use of genetically engineered pigs as tissue and organ donors for xenotransplantation has helped to address these hurdles. Although several preclinical trials have been conducted in nonhuman primates, some barriers still exist and demand further efforts. This review focuses on the recent advances and remaining challenges in organ and tissue xenotransplantation.
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Affiliation(s)
- Asghar Ali
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany; , ,
- Center for Innovative Medical Models (CiMM), LMU Munich, Oberschleißheim, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICONLMU), LMU Munich, Munich, Germany
| | - Elisabeth Kemter
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany; , ,
- Center for Innovative Medical Models (CiMM), LMU Munich, Oberschleißheim, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICONLMU), LMU Munich, Munich, Germany
| | - Eckhard Wolf
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany; , ,
- Center for Innovative Medical Models (CiMM), LMU Munich, Oberschleißheim, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICONLMU), LMU Munich, Munich, Germany
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Li Y, Fan H, Qin W, Wang Y, Chen S, Bao W, Sun MA. Regulation of the three-dimensional chromatin organization by transposable elements in pig spleen. Comput Struct Biotechnol J 2023; 21:4580-4588. [PMID: 37790243 PMCID: PMC10542605 DOI: 10.1016/j.csbj.2023.09.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/23/2023] [Accepted: 09/23/2023] [Indexed: 10/05/2023] Open
Abstract
Like other mammalian species, the pig genome is abundant with transposable elements (TEs). The importance of TEs for three-dimensional (3D) chromatin organization has been observed in species like human and mouse, yet current understanding about pig TEs is absent. Here, we investigated the contribution of TEs for the 3D chromatin organization in three pig tissues, focusing on spleen which is crucial for both adaptive and innate immunity. We identified dozens of TE families overrepresented with CTCF binding sites, including LTR22_SS, LTR15_SS and LTR16_SSc which are pig-specific families of endogenous retroviruses (ERVs). Interestingly, LTR22_SS elements harbor a CTCF motif and create hundreds of CTCF binding sites that are associated with adaptive immunity. We further applied Hi-C to profile the 3D chromatin structure in spleen and found that TE-derived CTCF binding sites correlate with chromatin insulation and frequently overlap TAD borders and loop anchors. Notably, one LTR22_SS-derived CTCF binding site demarcate a TAD boundary upstream of XCL1, which is a spleen-enriched chemokine gene important for lymphocyte trafficking and inflammation. Overall, this study represents a first step toward understanding the function of TEs on 3D chromatin organization regulation in pigs and expands our understanding about the functional importance of TEs in mammals.
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Affiliation(s)
- Yuzhuo Li
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Hairui Fan
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Weiyun Qin
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Yejun Wang
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen 518060, China
| | - Shuai Chen
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Wenbin Bao
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Ming-an Sun
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
- Joint International Research Laboratory of Important Animal Infectious Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou 225009, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China
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Fandiño S, Gomez-Lucia E, Benítez L, Doménech A. Avian Leukosis: Will We Be Able to Get Rid of It? Animals (Basel) 2023; 13:2358. [PMID: 37508135 PMCID: PMC10376345 DOI: 10.3390/ani13142358] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Avian leukosis viruses (ALVs) have been virtually eradicated from commercial poultry. However, some niches remain as pockets from which this group of viruses may reemerge and induce economic losses. Such is the case of fancy, hobby, backyard chickens and indigenous or native breeds, which are not as strictly inspected as commercial poultry and which have been found to harbor ALVs. In addition, the genome of both poultry and of several gamebird species contain endogenous retroviral sequences. Circumstances that support keeping up surveillance include the detection of several ALV natural recombinants between exogenous and endogenous ALV-related sequences which, combined with the well-known ability of retroviruses to mutate, facilitate the emergence of escape mutants. The subgroup most prevalent nowadays, ALV-J, has emerged as a multi-recombinant which uses a different receptor from the previously known subgroups, greatly increasing its cell tropism and pathogenicity and making it more transmissible. In this review we describe the ALVs, their different subgroups and which receptor they use to infect the cell, their routes of transmission and their presence in different bird collectivities, and the immune response against them. We analyze the different systems to control them, from vaccination to the progress made editing the bird genome to generate mutated ALV receptors or selecting certain haplotypes.
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Affiliation(s)
- Sergio Fandiño
- Department of Animal Health, Veterinary Faculty, Complutense University of Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain
- Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Complutense University of Madrid (UCM), C. de José Antonio Novais 12, 28040 Madrid, Spain
- Research Group, "Animal Viruses" of Complutense University of Madrid, 28040 Madrid, Spain
| | - Esperanza Gomez-Lucia
- Department of Animal Health, Veterinary Faculty, Complutense University of Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain
- Research Group, "Animal Viruses" of Complutense University of Madrid, 28040 Madrid, Spain
| | - Laura Benítez
- Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Complutense University of Madrid (UCM), C. de José Antonio Novais 12, 28040 Madrid, Spain
- Research Group, "Animal Viruses" of Complutense University of Madrid, 28040 Madrid, Spain
| | - Ana Doménech
- Department of Animal Health, Veterinary Faculty, Complutense University of Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain
- Research Group, "Animal Viruses" of Complutense University of Madrid, 28040 Madrid, Spain
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5
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Kass DH, Beatty S, Smith A, Scott M, Shah D, Czaplicki M. The discovery of multiple active mys-related LTR-retroelements within the Neotominae subfamily of cricetid rodents. Genetica 2023:10.1007/s10709-023-00183-z. [PMID: 36869995 DOI: 10.1007/s10709-023-00183-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/17/2023] [Indexed: 03/05/2023]
Abstract
Retrotransposon families in the rodent family Cricetidae have been understudied in contrast to Muridae, both taxa classified within the superfamily Muroidea. Therefore, we carried out a study to advance our knowledge of the unique mys LTR-retroelement identified in Peromyscus leucopus, by incorporating intra-ORF PCR, quantitative dot blots, DNA and protein library screens, the generation of molecular phylogenies, and analyses of orthologous LTR-retroelement loci. These analyses led to the discovery of three additional related families of LTR-retroelements, which include a 2900 bp full-length element of mys-related sequences (mysRS), an 8000 bp element containing the mys ORF1 sequence (mORF1) with ERV-related sequences downstream in the reverse orientation, as well as an 1800 bp element primarily consisting of mys ORF2 (mORF2) related sequences flanked by LTRs. Our data revealed only a few full-length mys elements among genera of the Neotominae subfamily of cricetid rodents, most existing as partial copies. The mysRS and mORF1 elements are also limited to the genomes of the Neotominae subfamily, whereas mORF2 appears to be restricted to the Peromyscus genus. Molecular phylogenies demonstrating concerted evolution along with an assessment of orthologous loci in Peromyscus for the presence or absence of elements are consistent with activity of these novel LTR-retroelement families within this genus. Together with known activity of various families of non-LTR retroelements in Peromyscus species, we propose that retrotransposons have been continually contributing to the dynamics of Peromyscus genomes promoting genomic diversity and may be correlated with the evolution of more than 50 identified Peromyscus species.
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Affiliation(s)
- David H Kass
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA.
| | - Sarah Beatty
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Ashlee Smith
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Megan Scott
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Dishita Shah
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Mary Czaplicki
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
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Liu Y, Niu Y, Ma X, Xiang Y, Wu D, Li W, Wang T, Niu D. Porcine endogenous retrovirus: classification, molecular structure, regulation, function, and potential risk in xenotransplantation. Funct Integr Genomics 2023; 23:60. [PMID: 36790562 DOI: 10.1007/s10142-023-00984-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 02/16/2023]
Abstract
Xenotransplantation with porcine organs has been recognized as a promising solution to alleviate the shortage of organs for human transplantation. Porcine endogenous retrovirus (PERV), whose proviral DNAs are integrated in the genome of all pig breeds, is a main microbiological risk for xenotransplantation. Over the last decades, some advances on PERVs' studies have been achieved. Here, we reviewed the current progress of PERVs including the classification, molecular structure, regulation, function in immune system, and potential risk in xenotransplantation. We also discussed the problem of insufficient study on PERVs as well as the questions need to be answered in the future work.
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Affiliation(s)
- Yu Liu
- College of Animal Science and Technology & College of Veterinary Medicine, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, China
| | - Yifan Niu
- College of Animal Science and Technology & College of Veterinary Medicine, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, China
| | - Xiang Ma
- College of Animal Science and Technology & College of Veterinary Medicine, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, China.,College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.,Jinhua Jinfan Feed Co., Ltd, Jinhua, Zhejiang, 321000, China
| | - Yun Xiang
- Jinhua Academy of Agricultural Sciences, Jinhua, Zhejiang, 321000, China
| | - De Wu
- Postdoctoral Research Station, Jinhua Development Zone, Jinhua, Zhejiang, 321000, China
| | - Weifen Li
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
| | - Tao Wang
- Nanjing Kgene Genetic Engineering Co., Ltd, Nanjing, Jiangsu, 211300, China.
| | - Dong Niu
- College of Animal Science and Technology & College of Veterinary Medicine, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, China.
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Lu TF, Sun B, Yu TY, Wu YJ, Zhou J, Wu SG. Porcine Endogenous Retroviruses: Quantification of the Viral Copy Number for the Four Miniature Pig Breeds in China. Front Microbiol 2022; 13:840347. [PMID: 35369498 PMCID: PMC8965148 DOI: 10.3389/fmicb.2022.840347] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 01/12/2022] [Indexed: 11/13/2022] Open
Abstract
Domestic pigs has served not only as one of the most important economy livestock but also as ideal organ-source animals owing to similarity in anatomy, physiology, and organ size to humans. Howerer, the barrier of the cross-species transmission risk of porcine endogenous retrovirus (PERVs) blocked the pig-to-human xenotransplantation. PERVs are integrated into pigs’ genomes and cannot be eliminated by designated or specified pathogen-free breeding. PERVs are an important biosafety issue in xenotransplantation because they can be released from normal pig cells and infect human cells in vitro under certain conditions. Screening and analyzing the presence of PERVs in pig genome will provide essential parameters for pig breed sources. In China, four miniature pig breeds, such as Guizhou miniature pig (GZ), Bama miniature pig (BM), Wuzhishan miniature pig (WZS), and Juema miniature pig (JM), were the main experimental miniature pig breeds, which were widely used. In this study, PCR was performed to amplify env-A, env-B, and env-C for all individuals from the four breeds. The results revealed that PERV env-A and env-B were detected in all individuals and the lowest ratios of PERV env-C was 17.6% (3/17) in the GZ breed. Then, PERV pol and GAPDH were detected using the droplet digital PCR (ddPCR) method. As the reference of GAPDH copy number, the copy numbers of PERVs were at the median of 12, 16, 14, and 16 in the four miniature pig breeds (GZ, BM, WZS, and JM), respectively. Furthermore, the copy number of the PERV pol gene in many organs from the GZ breed was analyzed using ddPCR. The copy numbers of PERV pol gene were at the median of 7 copies, 8 copies, 8 copies, 11 copies, 5 copies, 6 copies, and 7 copies in heart, liver, spleen, lung, kidney, muscle, and skin, and the maximum number was 11 copies in the lung. The minimum number was 5 copies in the kidney as the reference of GAPDH. These data suggest that GZ breed has the lower PERVs copy number in the genome, and may be an ideal organ-source miniature pig breed for the study of the pig-to-human xenotransplantation.
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Affiliation(s)
- Tao-Feng Lu
- Institute for Laboratory Animal Research, Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Bo Sun
- The First Clinical Medical College, Jinan University, Guangzhou, China
| | - Tai-Yong Yu
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Yan-Jun Wu
- Institute for Laboratory Animal Research, Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Jie Zhou
- Shanghai Laboratory Animal Research Center, Shanghai, China
| | - Shu-Guang Wu
- Institute for Laboratory Animal Research, Guizhou University of Traditional Chinese Medicine, Guiyang, China
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Denner J. Vaccination against the Koala Retrovirus (KoRV): Problems and Strategies. Animals (Basel) 2021; 11:ani11123555. [PMID: 34944329 PMCID: PMC8697897 DOI: 10.3390/ani11123555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/03/2021] [Accepted: 12/09/2021] [Indexed: 02/07/2023] Open
Abstract
The koala retrovirus (KoRV) is spreading in the koala population from the north to the south of Australia and is also in the process of endogenization into the koala genome. Virus infection is associated with tumorigenesis and immunodeficiency and is contributing to the decline of the animal population. Antibody production is an excellent marker of retrovirus infection; however, animals carrying endogenous KoRV are tolerant. Therefore, the therapeutic immunization of animals carrying endogenous KoRV seems to be ineffective. Using the recombinant transmembrane (TM) envelope protein of the KoRV, we immunized goats, rats and mice, obtaining in all cases neutralizing antibodies which recognize epitopes in the fusion peptide proximal region (FPPR), and in the membrane-proximal external region (MPER). Immunizing several animal species with the corresponding TM envelope protein of the closely related porcine endogenous retrovirus (PERV), as well as the feline leukemia virus (FeLV), we also induced neutralizing antibodies with similar epitopes. Immunizing with the TM envelope protein in addition to the surface envelope proteins of all three viruses resulted in higher titers of neutralizing antibodies. Immunizing KoRV-negative koalas with our vaccine (which is composed of both envelope proteins) may protect these animals from infection, and these may be the starting points of a virus-free population.
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Affiliation(s)
- Joachim Denner
- Institute of Virology, Free University Berlin, Robert von Ostertag-Str. 7-13, 14163 Berlin, Germany
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Denner J. Porcine Endogenous Retroviruses and Xenotransplantation, 2021. Viruses 2021; 13:v13112156. [PMID: 34834962 PMCID: PMC8625113 DOI: 10.3390/v13112156] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/06/2021] [Accepted: 10/20/2021] [Indexed: 12/25/2022] Open
Abstract
Porcine endogenous retroviruses (PERVs) are integrated in the genome of all pigs, and some of them are able to infect human cells. Therefore, PERVs pose a risk for xenotransplantation, the transplantation of pig cells, tissues, or organ to humans in order to alleviate the shortage of human donor organs. Up to 2021, a huge body of knowledge about PERVs has been accumulated regarding their biology, including replication, recombination, origin, host range, and immunosuppressive properties. Until now, no PERV transmission has been observed in clinical trials transplanting pig islet cells into diabetic humans, in preclinical trials transplanting pig cells and organs into nonhuman primates with remarkable long survival times of the transplant, and in infection experiments with several animal species. Nevertheless, in order to prevent virus transmission to the recipient, numerous strategies have been developed, including selection of PERV-C-free animals, RNA interference, antiviral drugs, vaccination, and genome editing. Furthermore, at present there are no more experimental approaches to evaluate the full risk until we move to the clinic.
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Affiliation(s)
- Joachim Denner
- Department of Veterinary Medicine, Institute of Virology, Free University Berlin, 14163 Berlin, Germany
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High Prevalence of Recombinant Porcine Endogenous Retroviruses (PERV-A/Cs) in Minipigs: A Review on Origin and Presence. Viruses 2021; 13:v13091869. [PMID: 34578447 PMCID: PMC8473008 DOI: 10.3390/v13091869] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 12/17/2022] Open
Abstract
Minipigs play an important role in biomedical research and they have also been used as donor animals for preclinical xenotransplantations. Since zoonotic microorganisms including viruses can be transmitted when pig cells, tissues or organs are transplanted, virus safety is an important feature in xenotransplantation. Whereas most porcine viruses can be eliminated from pig herds by different strategies, this is not possible for porcine endogenous retroviruses (PERVs). PERVs are integrated in the genome of pigs and some of them release infectious particles able to infect human cells. Whereas PERV-A and PERV-B are present in all pigs and can infect cells from humans and other species, PERV-C is present in most, but not all pigs and infects only pig cells. Recombinant viruses between PERV-A and PERV-C have been found in some pigs; these recombinants infect human cells and are characterized by high replication rates. PERV-A/C recombinants have been found mainly in minipigs of different origin. The possible reasons of this high prevalence of PERV-A/C in minipigs, including inbreeding and higher numbers and expression of replication-competent PERV-C in these animals, are discussed in this review. Based on these data, it is highly recommended to use only pig donors in clinical xenotransplantation that are negative for PERV-C.
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Denner J. Detection of cell-free pig DNA using integrated PERV sequences to monitor xenotransplant tissue damage and rejection. Xenotransplantation 2021; 28:e12688. [PMID: 33779009 DOI: 10.1111/xen.12688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/09/2021] [Accepted: 03/18/2021] [Indexed: 11/27/2022]
Affiliation(s)
- Joachim Denner
- Institute of Virology, Free University Berlin, Berlin, Germany
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