Are there better assays to evaluate the risk of transmission of porcine endogenous retroviruses (PERVs) to human cells?

2019 ◽  
Vol 26 (4) ◽  
Author(s):  
Joachim Denner ◽  
Linda Scobie
Keyword(s):  
Human Cells ◽  
Endogenous Retroviruses ◽  
Porcine Endogenous Retroviruses

scholarly journals Absence of Replication-Competent Human-Tropic Porcine Endogenous Retroviruses in the Germ Line DNA of Inbred Miniature Swine

2004 ◽  
Vol 78 (5) ◽  
pp. 2502-2509 ◽  
Author(s):  
Linda Scobie ◽  
Samantha Taylor ◽  
James C. Wood ◽  
Kristen M. Suling ◽  
Gary Quinn ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Germ Line ◽  
Human Cells ◽  
Endogenous Retroviruses ◽  
Open Reading Frames ◽  
Miniature Swine ◽  
Dna Libraries ◽  
Porcine Endogenous Retroviruses ◽  
Perv Transmission

ABSTRACT The potential transmission of porcine endogenous retroviruses (PERVs) has raised concern in the development of porcine xenotransplantation products. Our previous studies have resulted in the identification of animals within a research herd of inbred miniature swine that lack the capacity to transmit PERV to human cells in vitro. In contrast, other animals were capable of PERV transmission. The PERVs that were transmitted to human cells are recombinants between PERV-A and PERV-C in the post-VRA region of the envelope (B. A. Oldmixon, J. C. Wood, T. A. Ericsson, C. A. Wilson, M. E. White-Scharf, G. Andersson, J. L. Greenstein, H. J. Schuurman, and C. Patience, J. Virol. 76:3045-3048, 2002); these viruses we term PERV-A/C. This observation prompted us to determine whether these human-tropic replication-competent (HTRC) PERV-A/C recombinants were present in the genomic DNA of these miniature swine. Genomic DNA libraries were generated from one miniature swine that transmitted HTRC PERV as well as from one miniature swine that did not transmit HTRC PERV. HTRC PERV-A/C proviruses were not identified in the germ line DNAs of these pigs by using genomic mapping. Similarly, although PERV-A loci were identified in both libraries that possessed long env open reading frames, the Env proteins encoded by these loci were nonfunctional according to pseudotype assays. In the absence of a germ line source for HTRC PERV, further studies are warranted to assess the mechanisms by which HTRC PERV can be generated. Once identified, it may prove possible to generate animals with further reduced potential to produce HTRC PERV.

scholarly journals Establishment and Characterization of Molecular Clones of Porcine Endogenous Retroviruses Replicating on Human Cells

2000 ◽  
Vol 74 (9) ◽  
pp. 4028-4038 ◽  
Author(s):  
Frank Czauderna ◽  
Nicole Fischer ◽  
Klaus Boller ◽  
Reinhard Kurth ◽  
Ralf R. Tönjes
Keyword(s):  
Reverse Transcriptase Activity ◽  
Human Cells ◽  
Endogenous Retroviruses ◽  
Start Codon ◽  
293 Cells ◽  
Porcine Endogenous Retroviruses ◽  
Class B ◽  
Pig Genome ◽  
Genetic Recombinant

ABSTRACT The use of pig xenografts is being considered to alleviate the shortage of allogeneic organs for transplantation. In addition to the problems overcoming immunological and physiological barriers, the existence of numerous porcine microorganisms poses the risk of initiating a xenozoonosis. Recently, different classes of type C porcine endogenous retoviruses (PERV) which are infectious for human cells in vitro have been partially described. We therefore examined whether completely intact proviruses exist that produce infectious and replication-competent virions. Several proviral PERV sequences were cloned and characterized. One molecular PERV class B clone, PERV-B(43), generated infectious particles after transfection into human 293 cells. A second clone, PERV-B(33), which was highly homologous to PERV-B(43), showed a G-to-A mutation in the first start codon (Met to Ile) of the env gene, preventing this provirus from replicating. However, a genetic recombinant, PERV-B(33)/ATG, carrying a restoredenv start codon, became infectious and could be serially passaged on 293 cells similar to virus clone PERV-B(43). PERV protein expression was detected 24 to 48 h posttransfection (p.t.) using cross-reacting antiserum, and reverse transcriptase activity was found at 12 to 14 days p.t. The transcriptional start and stop sites as well as the splice donor and splice acceptor sites of PERV mRNA were mapped, yielding a subgenomic env transcript of 3.1 kb. PERV-B(33) and PERV-B(43) differ in the number of copies of a 39-bp segment in the U3 region of the long terminal repeat. Strategies to identify and to specifically suppress or eliminate those proviruses from the pig genome might help in the production of PERV-free animals.

scholarly journals Antiretroviral Agents Inhibit Infection of Human Cells by Porcine Endogenous Retroviruses

2000 ◽  
Vol 44 (12) ◽  
pp. 3432-3433 ◽  
Author(s):  
S. K. Powell ◽  
M. E. Gates ◽  
G. Langford ◽  
M.-L. Gu ◽  
C. Lockey ◽  
...  
Keyword(s):  
Nucleoside Analogs ◽  
Antiretroviral Drugs ◽  
Human Cells ◽  
Endogenous Retroviruses ◽  
Antiretroviral Agents ◽  
Porcine Endogenous Retroviruses

ABSTRACT The efficacy of antiretroviral drugs against porcine endogenous retroviruses (PERV) that may be harbored in pig organs intended for transplantation was examined in human cells in vitro. The nucleoside analogs zidovudine and dideoxyinosine were found to effectively inhibit PERV replication.

scholarly journals Determinants of High Titer in Recombinant Porcine Endogenous Retroviruses

2004 ◽  
Vol 78 (24) ◽  
pp. 13871-13879 ◽  
Author(s):  
Ian Harrison ◽  
Yasuhiro Takeuchi ◽  
Birke Bartosch ◽  
Jonathan P. Stoye
Keyword(s):  
Molecular Basis ◽  
High Titer ◽  
Human Cells ◽  
Endogenous Retroviruses ◽  
The Novel ◽  
Rich Region ◽  
Variable Regions ◽  
Porcine Endogenous Retroviruses ◽  
Primary Determinant ◽  
Proline Rich Region

ABSTRACT Porcine endogenous retroviruses (PERVs) pose a potential stumbling block for therapeutic xenotransplantation, with the greatest threat coming from viruses generated by recombination between members of the PERV subgroup A (PERV-A) and PERV-C families (PERV-A/C recombinants). PERV-A and PERV-B have been shown to infect human cells in culture, albeit with low titers. PERV-C has a more restricted host range and cannot infect human cells. A recombinant PERV-A/C virus (PERV-A14/220) contains the PERV-A sequence between the end of pol and the middle of the SU region in env. The remaining sequence is derived from PERV-C. PERV-A14/220 is approximately 500-fold more infectious than PERV-A. To determine the molecular basis for the increased infectivity of PERV-A14/220, we have made a series of vector constructs. The primary determinant for the enhanced replicative potential of the recombinant virus appeared to be the env gene. Using a series of chimeric env genes, we could identify two determinants of high infectivity; one was an isoleucine to valine substitution at position 140 between variable regions A and B, and the other lies within the proline rich region. Taken together, these results show that the novel juxtaposition of env gene sequences enhanced the infectivity of PERV-A14/220 for human cells, perhaps by stabilization of the envelope glycoprotein or increased receptor binding.

scholarly journals High Prevalence of Recombinant Porcine Endogenous Retroviruses (PERV-A/Cs) in Minipigs: A Review on Origin and Presence

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1869
Author(s):  
Joachim Denner ◽  
Hendrik Jan Schuurman
Keyword(s):  
Biomedical Research ◽  
Human Cells ◽  
Endogenous Retroviruses ◽  
Recombinant Viruses ◽  
Porcine Endogenous Retroviruses ◽  
High Prevalence ◽  
Virus Safety ◽  
Different Origin

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.

scholarly journals Characterization of Chromosomally Assigned Replication-Competent Gamma Porcine Endogenous Retroviruses Derived from a Large White Pig and Expression in Human Cells

2002 ◽  
Vol 76 (6) ◽  
pp. 2714-2720 ◽  
Author(s):  
Marcus Niebert ◽  
Claire Rogel-Gaillard ◽  
Patrick Chardon ◽  
Ralf R. Tönjes
Keyword(s):  
Bac Library ◽  
Artificial Chromosome ◽  
Human Cells ◽  
Endogenous Retroviruses ◽  
Chromosome 1 ◽  
Transplant Proc ◽  
Large White ◽  
Porcine Endogenous Retroviruses

ABSTRACT Vertically transmitted endogenous retroviruses pose an infectious risk in the course of pig-to-human transplantation of cells, tissues, and organs. Two classes of polytropic type C porcine endogenous retroviruses (PERV) productively infect human cells in vitro. The cloning and characterization of replication-competent PERV-B sequences from infected human cells (F. Czauderna, N. Fischer, K. Boller, R. Kurth, and R. R. Tönjes, J. Virol. 74:4028-4038, 2000) as well as the cloning of functional PERV-A and -B sequences from porcine cell line PK15 (U. Krach, N. Fischer, F. Czauderna, and R. R. Tönjes, J. Virol. 75:5465-5472, 2001) have been previously described. Here we report the isolation of four full-length proviral sequences from a porcine bacterial artificial chromosome (BAC) library that comprises chromosomally assigned PERV. Clones Bac-PERV-A(130A12) and Bac-PERV-A(151B10) map to pig chromosome 1 and demonstrate close homology to PK15-PERV-A(58) in env and to PERV-MSL in long terminal repeat (LTR), gag, and pro/pol sequences. Clone Bac-PERV-A(463H12) is located on pig chromosome 3 and demonstrates close homology to PK15-PERV-A(58) in env and to 293-PERV-B(43) in LTR, gag, and pro/pol (Czauderna et al.; R. R. Tönjes, F. Czauderna, N. Fischer, U. Krach, K. Boller, P. Chardon, C. Rogel-Gailard, M. Niebert, G. Scheef, A. Werner, and R. Kurth, Transplant Proc. 32:1158-1161, 2000). Clone Bac-PERV-B(192B9) is located on pig chromosome 7 in the swine leukocyte antigen region and is highly homologous with but distinct from the previously described functional clone 293-PERV-B(43) and bears the number of repeats initially observed in the LTRs of clone 293-PERV-A(42) (Czauderna et al.; Krach et al.). Clones Bac-PERV-A(130A12), Bac-PERV-A(151B10), and Bac-PERV-A(463H12) were replication competent upon transfection into susceptible 293 and HeLa cells. Bac-PERV-B(192B9), however, bears two stop codons in pro/pol preventing this clone from being replication competent in some individual pigs, but initial screenings indicate that this provirus might be intact in others. The data suggest that the porcine genome harbors a limited number of infectious PERV sequences, allowing for specific screening in different pig breeds.

scholarly journals Porcine endogenous retroviruses PERV A and A/C recombinant are insensitive to a range of divergent mammalian TRIM5α proteins including human TRIM5α

2009 ◽  
Vol 90 (3) ◽  
pp. 702-709 ◽  
Author(s):  
Andrew Wood ◽  
Benjamin L. J. Webb ◽  
Birke Bartosch ◽  
Torsten Schaller ◽  
Yasuhiro Takeuchi ◽  
...  
Keyword(s):  
Potential Risk ◽  
Human Cells ◽  
Endogenous Retroviruses ◽  
Organ Donors ◽  
Recombinant Clone ◽  
Porcine Endogenous Retroviruses

The potential risk of cross-species transmission of porcine endogenous retroviruses (PERV) to humans has slowed the development of xenotransplantation, using pigs as organ donors. Here, we show that PERVs are insensitive to restriction by divergent TRIM5α molecules despite the fact that they strongly restrict a variety of divergent lentiviruses. We also show that the human PERV A/C recombinant clone 14/220 reverse transcribes with increased efficiency in human cells, leading to significantly higher infectivity. We conclude that xenotransplantation studies should consider the danger of highly infectious TRIM5α-insensitive human-tropic PERV recombinants.

Molecularly cloned porcine endogenous retroviruses replicate on human cells

2000 ◽  
Vol 32 (5) ◽  
pp. 1158-1161 ◽  
Author(s):  
R.R Tönjes ◽  
F Czauderna ◽  
N Fischer ◽  
U Krach ◽  
K Boller ◽  
...  
Keyword(s):  
Human Cells ◽  
Endogenous Retroviruses ◽  
Porcine Endogenous Retroviruses

Unexpected low expression of porcine endogenous retroviruses (PERVs) in porcine expanded potential stem cells (EPSCs)

2021 ◽  
pp. 198295
Author(s):  
Luise Krüger ◽  
Monika Nowak-Imialek ◽  
Yannick Kristiansen ◽  
Doris Herrmann ◽  
Björn Petersen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endogenous Retroviruses ◽  
Porcine Endogenous Retroviruses ◽  
Low Expression
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