scholarly journals Identification of a novel type C porcine endogenous retrovirus: evidence that copy number of endogenous retroviruses increases during host inbreeding

2001 ◽  
Vol 82 (8) ◽  
pp. 1829-1834 ◽  
Author(s):  
Rui Mang ◽  
Jolanda Maas ◽  
Xianghong Chen ◽  
Jaap Goudsmit ◽  
Antoinette C. van der Kuyl
Keyword(s):  
Wild Boar ◽  
Copy Number ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Human Endogenous Retrovirus ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses ◽  
Pig Genome ◽  
Multiple Copies ◽  
Type C

Different classes of porcine endogenous retroviruses (PERVs), which have the potential to infect humans during xenotransplantation, have been isolated from the pig genome. Because vertebrate genomes may contain numerous endogenous retrovirus sequences, the pig genome was examined for additional endogenous retroviruses, resulting in the isolation of a novel, complete endogenous retrovirus genome, designated PERV-E. The gag, pol and env genes of PERV-E are closely related to those of human endogenous retrovirus (HERV) 4-1, which belongs to the HERV-E family. Results of studies to determine the presence and copy number of PERVs demonstrated that PERV-E and PERV-A/B-like proviruses were present in all genomes tested, but that PERV-C was not found in two of the species examined, including wild boar. Multiple copies of PERVs could be found in each pig genome. Among all of the pig genomes tested, the wild boar genome had the lowest copy number of all PERVs, suggesting that the number of integrations of complete endogenous retroviruses is increased by inbreeding.

scholarly journals Copy Number and Prevalence of Porcine Endogenous Retroviruses (PERVs) in German Wild Boars

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 419
Author(s):  
Luise Krüger ◽  
Milena Stillfried ◽  
Carolin Prinz ◽  
Vanessa Schröder ◽  
Lena Katharina Neubert ◽  
...  
Keyword(s):  
Wild Boar ◽  
Copy Number ◽  
Digital Pcr ◽  
Endogenous Retroviruses ◽  
Wild Boars ◽  
Domestic Pigs ◽  
Copy Numbers ◽  
Cellular Genes ◽  
Porcine Endogenous Retroviruses ◽  
Different Populations

Porcine endogenous retroviruses (PERVs) are integrated in the genome of pigs and are transmitted like cellular genes from parents to the offspring. Whereas PERV-A and PERV-B are present in all pigs, PERV-C was found to be in many, but not all pigs. When PERV-C is present, recombination with PERV-A may happen and the PERV-A/C recombinants are characterized by a high replication rate. Until now, nothing has been known about the copy number of PERVs in wild boars and little is known about the prevalence of the phylogenetically youngest PERV-C in ancient wild boars. Here we investigated for the first time the copy number of PERVs in different populations of wild boars in and around Berlin using droplet digital PCR. Copy numbers between 3 and 69 per genome have been measured. A lower number but a higher variability was found compared to domestic pigs, including minipigs reported earlier (Fiebig et al., Xenotransplantation, 2018). The wild boar populations differed genetically and had been isolated during the existence of the Berlin wall. Despite this, the variations in copy number were larger in a single population compared to the differences between the populations. PERV-C was found in all 92 analyzed animals. Differences in the copy number of PERV in different organs of a single wild boar indicate that PERVs are also active in wild boars, replicating and infecting new cells as has been shown in domestic pigs.

scholarly journals The Relationship between Embryonic Development and the Efficiency of Target Mutations in Porcine Endogenous Retroviruses (PERVs) Pol Genes in Porcine Embryos

Animals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 593 ◽  
Author(s):  
Maki Hirata ◽  
Manita Wittayarat ◽  
Takayuki Hirano ◽  
Nhien Thi Nguyen ◽  
Quynh Anh Le ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Genome Editing ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Cell Stage ◽  
Gene Target ◽  
Porcine Endogenous Retrovirus ◽  
Cas9 Protein ◽  
Pig Genome ◽  
The Relationship

Porcine endogenous retrovirus (PERV) is a provirus found in the pig genome that may act as an infectious pathogen in humans who receive pig organ xenotransplantation. Inactivation of the PERV pol gene in porcine cells reportedly affects cell growth. Therefore, the mutation of PERV pol gene in porcine embryos using genome editing may affect the embryonic development. The present study was carried out to investigate the relationship between the mutation of the PERV pol gene in porcine embryos and their development. We introduced, either alone or in combination, three different gRNAs (gRNA1, 2, and 3) into porcine zygotes by genome editing using electroporation of the Cas9 protein (GEEP) system. All three gRNAs targeted the PERV pol gene, and we assessed their effects on porcine embryonic development. Our results showed that the blastocyst formation rates of zygotes electroporated with gRNA3—alone and in combination—were significantly lower (p < 0.05) than those of zygotes electroporated with gRNA1. The mutation rates assessed by the PERV pol gene target site sequencing in individual blastocysts and pooled embryos at the 2-to-8-cell stage did not differ among the three gRNAs. However, the frequency of indel mutations in mutant embryos at the 2-to-8-cell stage trended higher in the embryos electroporated with gRNA3 alone and in combination. Embryonic development may be affected by gRNAs that induce high-frequency indel mutations.

scholarly journals Isolation and Characterization of an Infectious Replication-Competent Molecular Clone of Ecotropic Porcine Endogenous Retrovirus Class C

2006 ◽  
Vol 80 (20) ◽  
pp. 10258-10261 ◽  
Author(s):  
Thomas Preuss ◽  
Nicole Fischer ◽  
Klaus Boller ◽  
Ralf R. Tönjes
Keyword(s):  
T Cells ◽  
Genomic Library ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Miniature Swine ◽  
Infectious Risk ◽  
Isolation And Characterization ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses

ABSTRACT Xenotransplantation of pig organs is complicated by the existence of polytropic replication-competent porcine endogenous retroviruses (PERV) capable of infecting human cells. The potential for recombination between ecotropic PERV-C and human-tropic PERV-A and PERV-B adds another level of infectious risk. Proviral PERV-C were characterized in MAX-T cells derived from d/d haplotype miniature swine. Three proviruses were cloned from a genomic library. Clone PERV-C(1312) generated infectious particles after transfection into porcine ST-IOWA cells. Electron microscopy revealed the same morphologies of virions in MAX-T cells and in ST-IOWA cells infected with cell-free PERV-C(1312) particles, indicating that MAX-T cells harbor one functional PERV-C provirus.

scholarly journals Relative Age of Proviral Porcine Endogenous Retrovirus Sequences in Sus scrofa Based on the Molecular Clock Hypothesis

2003 ◽  
Vol 77 (22) ◽  
pp. 12363-12368 ◽  
Author(s):  
Ralf R. Tönjes ◽  
Marcus Niebert
Keyword(s):  
Sus Scrofa ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Relative Age ◽  
Repeat Structure ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses ◽  
Different Types ◽  
Pecari Tajacu ◽  
Recent Origin

ABSTRACT Porcine endogenous retroviruses (PERV) are discussed as putative infectious agents in xenotransplantation. PERV classes A, B, and C harbor different envelope proteins. Two different types of long terminal repeat (LTR) structures exist, of which both are present only in PERV-A. One type of LTR contains a distinct repeat structure in U3, while the other is repeatless, conferring a lower level of transcriptional activity. Since the different LTR structures are distributed unequally among the proviruses and, apparently, PERV is the only virus harboring two different LTR structures, we were interested in determining which LTR is the ancestor. Replication-competent viruses can still be found today, suggesting an evolutionary recent origin. Our studies revealed that the age of PERV is at most 7.6 × 106 years, whereas the repeatless LTR type evolved approximately 3.4 × 106 years ago, being the phylogenetically younger structure. The age determined for PERV correlates with the time of separation between pigs (Suidae, Sus scrofa) and their closest relatives, American-born peccaries (Tayassuidae, Pecari tajacu), 7.4 × 106 years ago.

scholarly journals Genotyping of Porcine Endogenous Retroviruses from a Family of Miniature Swine

2004 ◽  
Vol 78 (1) ◽  
pp. 314-319 ◽  
Author(s):  
Gary Quinn ◽  
James Wood ◽  
Kristen Suling ◽  
Scott Arn ◽  
David H. Sachs ◽  
...  
Keyword(s):  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Target Cells ◽  
Nucleotide Polymorphisms ◽  
Miniature Swine ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses ◽  
The Family ◽  
Transcript Profiles

ABSTRACT The identification of animals in an inbred miniature swine herd that consistently fail to produce replication- competent humantropic porcine endogenous retrovirus (PERV) has prompted studies on the biology of PERV in transmitter and nontransmitter animals. We analyzed PERV RNA transcript profiles in a family of inbred miniature swine (SLAd/d haplotype) in which individual members differed in their capacity to generate humantropic and ecotropic (i.e., pigtropic) virus. We identified unique HaeIII and HpaII gag restriction fragment length polymorphism (RFLP) profiles resulting from single nucleotide polymorphisms in blood cells; these were found only in animals that produced humantropic PERV. These HaeIII and HpaII gag RFLP profiles proved to be components of humantropic PERV as they were transmitted to 293 human target cells in vitro. The humantropic HaeIII and HpaII gag RFLP genotypes in the family of study were not present in other miniature swine in the herd that produced humantropic PERV, indicating that these RFLP profiles relate specifically to this family's lineage.

scholarly journals Detection and Characterization of Porcine Endogenous Retrovirus in Porcine Plasma and Porcine Factor VIII

2001 ◽  
Vol 75 (10) ◽  
pp. 4551-4557 ◽  
Author(s):  
Daniel M. Takefman ◽  
Susan Wong ◽  
Thomas Maudru ◽  
Keith Peden ◽  
Carolyn A. Wilson
Keyword(s):  
Factor Viii ◽  
Mononuclear Cells ◽  
Infectious Virus ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Peripheral Blood Mononuclear ◽  
Porcine Endogenous Retrovirus ◽  
Pig Genome

ABSTRACT The pig genome contains porcine endogenous retroviruses (PERVs) capable of infecting human cells. Detection of infectious retrovirus in porcine peripheral blood mononuclear cells and endothelial cells suggested to us that pig plasma is likely to contain PERV. Both PERV env sequences and viral reverse transcriptase (RT) activity were detected in all plasma samples isolated from four NIH minipigs. To detect infectious virus from plasma, we performed a culture assay using three cell lines of feline, swine, and human origin that had previously been shown to be permissive for PERV. Infectious virus was successfully cultured from all four NIH minipig plasmas on the swine cell line ST-IOWA. Using RT-PCR with env-specific primers, we could detect expression of PERV class C envelope in the supernatant of ST-IOWA cells that had been exposed to each pig plasma. We next examined a pig plasma derivative, Hyate:C (porcine factor VIII), and found evidence of PERV particles, since all six lots examined were positive for PERV RNA and RT activity. However, infectious virus could not be detected in clinical lots of Hyate:C, suggesting that the manufacturing process might reduce the load of infectious virus to levels below detectable limits of the assay. Detection of infectious virus in porcine plasma confirms and extends the previous findings that certain porcine cells express PERV when manipulated in vitro and clearly demonstrates that there are porcine cells that express infectious PERV constitutively in vivo.

scholarly journals Characterization of Porcine Endogenous Retrovirus Clones from the NIH Miniature Pig BAC Library

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Seong-Lan Yu ◽  
Woo-Young Jung ◽  
Kie-Chul Jung ◽  
In-Cheol Cho ◽  
Hyun-Tae Lim ◽  
...  
Keyword(s):  
Bac Library ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Miniature Pig ◽  
Reading Frame ◽  
Porcine Endogenous Retrovirus ◽  
Open Reading Frame Length ◽  
Porcine Endogenous Retroviruses ◽  
Integration Sites

Pigs have been considered as donors for xenotransplantation in the replacement of human organs and tissues. However, porcine endogenous retroviruses (PERVs) might transmit new infectious disease to humans during xenotransplantation. To investigate PERV integration sites, 45 PERV-positive BAC clones, including 12 PERV-A, 16 PERV-B, and 17 PERV-C clones, were identified from the NIH miniature pig BAC library. The analysis of 12 selected full-length sequences of PERVs, including the long terminal repeat (LTR) region, identified the expected of open reading frame length, an indicative of active PERV, in all five PERV-C clones and one of the four PERV-B clones. Premature stop codons were observed in only three PERV-A clones. Also, eleven PERV integration sites were mapped using a 5000-rad IMpRH panel. The map locations of PERV-C clones have not been reported before, thus they are novel PERV clones identified in this study. The results could provide basic information for the elimination of site-specific PERVs in selection of pigs for xenotransplantation.

scholarly journals Porcine Endogenous Retrovirus Transmission Characteristics of an Inbred Herd of Miniature Swine

2002 ◽  
Vol 76 (6) ◽  
pp. 3045-3048 ◽  
Author(s):  
Beth A. Oldmixon ◽  
James C. Wood ◽  
Thomas A. Ericsson ◽  
Carolyn A. Wilson ◽  
Mary E. White-Scharf ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Receptor Binding Domain ◽  
Transmission Characteristics ◽  
Miniature Swine ◽  
Recombinant Viruses ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses

ABSTRACT Here we report the identification of inbred miniature swine that failed to produce human-tropic replication-competent porcine endogenous retroviruses (HTRC PERVs), using in vitro coculture assays. When HTRC PERVs were isolated from transmitting animals, all were recombinant viruses, with the receptor-binding domain of PERV-A combining with PERV-C-related sequences.

scholarly journals Lack of antibody response in pigs immunized with the transmembrane envelope protein of porcine endogenous retroviruses

2014 ◽  
Vol 95 (8) ◽  
pp. 1827-1831 ◽  
Author(s):  
Martina Keller ◽  
Björn Petersen ◽  
Heiner Niemann ◽  
Joachim Denner
Keyword(s):  
Neutralizing Antibodies ◽  
Mammalian Species ◽  
Neutralization Assay ◽  
Endogenous Retrovirus ◽  
Proximal Region ◽  
Endogenous Retroviruses ◽  
Placental Development ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses ◽  
Protein P15e

Recently, we immunized different mammalian species (goats, mice, rats, rabbits, guinea pigs and hamsters) with the recombinant ectodomain of the transmembrane envelope (TM) protein p15E of porcine endogenous retrovirus (PERV). In all cases, neutralizing immune sera were induced, which recognized epitopes in the fusion peptide proximal region and the membrane proximal external region of p15E. In order to analyse whether pigs are also able to produce such antibodies, and whether such antibodies can be used to study the involvement of the TM protein in placental development (as was shown for endogenous retroviruses of other species), German landrace pigs were immunized with PERV p15E. No binding and neutralizing antibodies were produced as shown in three Western blot analyses and in a neutralization assay, indicating that pigs are tolerant to their endogenous retroviruses, at least for the ectodomain of the TM protein.

scholarly journals Human Endogenous Retrovirus Reactivation: Implications for Cancer Immunotherapy

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1999
Author(s):  
Annacarmen Petrizzo ◽  
Concetta Ragone ◽  
Beatrice Cavalluzzo ◽  
Angela Mauriello ◽  
Carmen Manolio ◽  
...  
Keyword(s):  
Cancer Immunotherapy ◽  
Genetic Material ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Human Endogenous Retrovirus ◽  
Danger Signal ◽  
Human Endogenous Retroviruses ◽  
Double Stranded Rna ◽  
Specific Antigens ◽  
Viral Mimicry

Human endogenous retroviruses (HERVs) derive from ancestral exogenous retroviruses whose genetic material has been integrated in our germline DNA. Several lines of evidence indicate that cancer immunotherapy may benefit from HERV reactivation, which can be induced either by drugs or by cellular changes occurring in tumor cells. Indeed, several studies indicate that HERV proviral DNA can be transcribed either to double-stranded RNA (dsRNA) that is sensed as a “danger signal” by pattern recognition receptors (PRRs), leading to a viral mimicry state, or to mRNA that is translated into proteins that may contribute to the landscape of tumor-specific antigens (TSAs). Alternatively, HERV reactivation is associated with the expression of long noncoding RNAs (lncRNAs). In this review, we will highlight recent findings on HERV reactivation in cancer and its implications for cancer immunotherapy.

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