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Salamat MKF, Gossner A, Bradford B, Hunter N, Hopkins J, Houston F. Scrapie infection and endogenous retroviral expression in sheep lymphoid tissues. Vet Immunol Immunopathol 2021; 233:110194. [PMID: 33530020 DOI: 10.1016/j.vetimm.2021.110194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 12/28/2020] [Accepted: 01/08/2021] [Indexed: 01/09/2023]
Abstract
Transmissible spongiform encephalopathies, or prion diseases, are fatal neurodegenerative diseases affecting humans and animals. Although many host tissues express PrPC (essential for prion replication), relatively few cell types accumulate significant levels of infectivity, including neurons and other cell types in the nervous system, and follicular dendritic cells in secondary lymphoid organs. This suggests that tissue or cell-specific receptors or cofactors could play a role in controlling differential susceptibility to infection. Endogenous retroviruses (ERV), the remnants of ancient retroviral integration into the host germline, may represent one such cofactor. We examined the effect of scrapie infection on expression of three ovine ERV families (enJSRV/β1-OERV, γ1-OERV, γ2-OERV) in secondary lymphoid tissues of sheep at different time points following subcutaneous inoculation, using RT-qPCR. These OERVs were constitutively expressed in the prescapular lymph node and spleen of uninfected sheep. However, we were unable to find convincing evidence of specific differential expression of OERV in the same tissues following scrapie infection, in contrast to previous studies of ERV expression in brains of prion-infected mice and macaques. This study is the first to quantify the expression of potentially functional OERV transcripts in sheep lymphoid tissues, opening up interesting questions about the consequences for host immune function.
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Affiliation(s)
- M K F Salamat
- Division of Infection and Immunity, The Roslin Institute, R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - A Gossner
- Division of Infection and Immunity, The Roslin Institute, R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - B Bradford
- Division of Infection and Immunity, The Roslin Institute, R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - N Hunter
- Division of Infection and Immunity, The Roslin Institute, R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - J Hopkins
- Division of Infection and Immunity, The Roslin Institute, R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - F Houston
- Division of Infection and Immunity, The Roslin Institute, R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
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Lathe R, Darlix JL. Prion protein PrP nucleic acid binding and mobilization implicates retroelements as the replicative component of transmissible spongiform encephalopathy. Arch Virol 2020; 165:535-556. [PMID: 32025859 PMCID: PMC7024060 DOI: 10.1007/s00705-020-04529-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/13/2019] [Indexed: 12/21/2022]
Abstract
The existence of more than 30 strains of transmissible spongiform encephalopathy (TSE) and the paucity of infectivity of purified PrPSc, as well as considerations of PrP structure, are inconsistent with the protein-only (prion) theory of TSE. Nucleic acid is a strong contender as a second component. We juxtapose two key findings: (i) PrP is a nucleic-acid-binding antimicrobial protein that is similar to retroviral Gag proteins in its ability to trigger reverse transcription. (ii) Retroelement mobilization is widely seen in TSE disease. Given further evidence that PrP also mediates nucleic acid transport into and out of the cell, a strong case is to be made that a second element – retroelement nucleic acid – bound to PrP constitutes the second component necessary to explain the multiple strains of TSE.
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Affiliation(s)
- Richard Lathe
- Division of Infection Medicine, University of Edinburgh School of Medicine, Edinburgh, UK. .,Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Moscow, Moscow Region, Russia.
| | - Jean-Luc Darlix
- Faculté de Pharmacie, Centre Nationale de la Recherche Scientifique (CNRS) Laboratory of Bioimaging and Pathologies (Unité Mixte de Recherche 7021), Université de Strasbourg, Illkirch, France.
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Akiguchi I, Pallàs M, Budka H, Akiyama H, Ueno M, Han J, Yagi H, Nishikawa T, Chiba Y, Sugiyama H, Takahashi R, Unno K, Higuchi K, Hosokawa M. SAMP8 mice as a neuropathological model of accelerated brain aging and dementia: Toshio Takeda's legacy and future directions. Neuropathology 2017; 37:293-305. [PMID: 28261874 DOI: 10.1111/neup.12373] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 12/14/2022]
Abstract
Senescence accelerated mice P8 (SAMP8) show significant age-related deteriorations in memory and learning ability in accordance with early onset and rapid advancement of senescence. Brains of SAMP8 mice reveal an age-associated increase of PAS-positive granular structures in the hippocampal formation and astrogliosis in the brain stem and hippocampus. A spongy degeneration in the brain stem appears at 1 month of age and reaches a maximum at 4-8 months. In addition, clusters of activated microglia also appear around the vacuoles in the brain stem. β/A4(Aβ) protein-like immunoreactive granular structures are observed in various regions and increase in number markedly with age. Other age-associated histological changes include cortical atrophy, neuronal cell loss in locus coeruleus and lateral tegmental nuclei, intraneuronal accumulation of lipopigments in Purkinje cells and eosinophilic inclusion bodies in thalamic neurons. A blood-brain barrier dysfunction and astrogliosis are also prominent with advancing age in the hippocampus. These changes are generally similar to the pathomorphology of aging human brains and characterized by their association with some specific glioneuronal reactions. As for the hallmarks of Alzheimer brains, tau morphology has not yet been confirmed regardless of the age-related increase in phosphorylated tau in SAMP8 mice brains, but early age-related Aβ deposition in the hippocampus has recently been published. SAMP8 mice are, therefore, not only a senescence-accelerated model but also a promising model for Alzheimer's disease and other cognitive disorders.
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Affiliation(s)
- Ichiro Akiguchi
- Center of Neurological and Cerebrovascular Diseases, Koseikai Takeda Hospital, Kyoto, Japan.,Department of Health Science, Kyoto Koka Women's University, Kyoto, Japan
| | - Mercè Pallàs
- Pharmacology Section and Institute of Neuroscience, University of Barcelona, Barcelona, Spain
| | - Herbert Budka
- Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland
| | - Haruhiko Akiyama
- Department of Clinical Research, Yokohama Brain and Spine Center, Yokohama, Japan
| | - Masaki Ueno
- Department of Pathology and Host Defence, Faculty of Medicine, Kagawa University, Takamatsu, Japan
| | - Jingxian Han
- The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Hideo Yagi
- Center of Neurological and Cerebrovascular Diseases, Koseikai Takeda Hospital, Kyoto, Japan
| | - Tomohumi Nishikawa
- Department of Health Science, Kyoto Koka Women's University, Kyoto, Japan
| | - Yoichi Chiba
- Department of Pathology and Host Defence, Faculty of Medicine, Kagawa University, Takamatsu, Japan
| | | | - Ryoya Takahashi
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Toho University, Chiba, Japan
| | - Keiko Unno
- School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Keiichi Higuchi
- Department of Aging Biology, Institute of Pathogenesis and Disease Prevention, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Masanori Hosokawa
- Institute for Developmental Research, Aichi Human Service Center, Nagoya, Japan
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Cellular Prion Protein Combined with Galectin-3 and -6 Affects the Infectivity Titer of an Endogenous Retrovirus Assayed in Hippocampal Neuronal Cells. PLoS One 2016; 11:e0167293. [PMID: 27936017 PMCID: PMC5147886 DOI: 10.1371/journal.pone.0167293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/11/2016] [Indexed: 11/19/2022] Open
Abstract
Prion diseases are infectious and fatal neurodegenerative diseases which require the cellular prion protein, PrPC, for development of diseases. The current study shows that the PrPC augments infectivity and plaque formation of a mouse endogenous retrovirus, MuLV. We have established four neuronal cell lines expressing mouse PrPC, PrP+/+; two express wild type PrPC (MoPrPwild) and the other two express mutant PrPC (MoPrPmut). Infection of neuronal cells from various PrP+/+ and PrP-/- (MoPrPKO) lines with MuLV yielded at least three times as many plaques in PrP+/+ than in PrP-/-. Furthermore, among the four PrP+/+ lines, one mutant line, P101L, had at least 2.5 times as many plaques as the other three PrP+/+ lines. Plaques in P101L were four times larger than those in other PrP+/+ lines. Colocalization of PrP and CAgag was seen in MuLV-infected PrP+/+ cells. In the PrP-MuLV interaction, the involvement of galectin-3 and -6 was observed by immunoprecipitation with antibody to PrPC. These results suggest that PrPC combined with galectin-3 and -6 can act as a receptor for MuLV. P101L, the disease form of mutant PrPC results suggest the genetic mutant form of PrPC may be more susceptible to viral infection.
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Douville RN, Nath A. Human endogenous retroviruses and the nervous system. HANDBOOK OF CLINICAL NEUROLOGY 2014; 123:465-85. [PMID: 25015500 DOI: 10.1016/b978-0-444-53488-0.00022-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Renée N Douville
- Department of Microbiology, University of Winnipeg, Winnipeg, Manitoba, Canada
| | - Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, MD, USA.
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Involvement of endogenous retroviruses in prion diseases. Pathogens 2013; 2:533-43. [PMID: 25437206 PMCID: PMC4235691 DOI: 10.3390/pathogens2030533] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 07/25/2013] [Accepted: 08/09/2013] [Indexed: 11/17/2022] Open
Abstract
For millions of years, vertebrates have been continuously exposed to infection by retroviruses. Ancient retroviral infection of germline cells resulted in the formation and accumulation of inherited retrovirus sequences in host genomes. These inherited retroviruses are referred to as endogenous retroviruses (ERVs), and recent estimates have revealed that a significant portion of animal genomes is made up of ERVs. Although various host factors have suppressed ERV activation, both positive and negative functions have been reported for some ERVs in normal and abnormal physiological conditions, such as in disease states. Similar to other complex diseases, ERV activation has been observed in prion diseases, and this review will discuss the potential involvement of ERVs in prion diseases.
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Lee YJ, Jeong BH, Choi EK, Carp RI, Kim YS. Complete genome sequences of new xenotropic murine leukemia viruses from the senescence-accelerated mouse (SAM): molecular and phylogenetic analyses. PLoS One 2013; 8:e55669. [PMID: 23393596 PMCID: PMC3564811 DOI: 10.1371/journal.pone.0055669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 12/28/2012] [Indexed: 01/18/2023] Open
Abstract
Approximately 10% of the mouse genome is constituted by endogenous retroviruses (ERVs), and a number of mouse ERVs remain active. Many copies of endogenous murine leukemia viruses (MuLVs) are detected in the genomes of inbred mouse strains. Some of these MuLVs are transcriptionally active or produce infectious virus particles. Previously, we identified partial env sequences of new xenotropic MuLVs (X-MuLVs) from a senescence-accelerated mouse (SAM) strain. In the present study, we investigated and characterized the complete sequences of the X-MuLVs. The complete genomes and open reading frames (ORFs) of two X-MuLVs, designated xmlv15 and xmlv18 (accession nos. HQ154630 and HQ154631, respectively), were molecularly cloned from the genome of the SAM mice. We confirmed that the xmlv15 and xmlv18 sequences are distinct from all known MuLV genomes and are most similar to DG-75 MuLV. Moreover, we found that common strains of laboratory mice carry our newly identified xmlvs. Additionally, the expression levels of xmlv15-related sequences were much higher in C57BL and ICR mice than in the SAM strains without any stimulators. Our findings suggest that a specific group of endogenous MuLVs is constitutively expressed in the brain and that they may participate in normal functions and/or pathogenic conditions.
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Affiliation(s)
- Yun-Jung Lee
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Kangwon-do, Republic of Korea
| | - Byung-Hoon Jeong
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea
| | - Eun-Kyoung Choi
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea
| | - Richard I. Carp
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Yong-Sun Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Gyeonggi-do, Republic of Korea
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Kangwon-do, Republic of Korea
- * E-mail:
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Jeong BH, Lee JH, Cho HJ, Kim YS. Absence of association between the incidence of BK virus and sporadic Creutzfeldt-Jakob disease. Intervirology 2013; 56:184-9. [PMID: 23363877 DOI: 10.1159/000346241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 11/23/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Many studies suggest that the virus-like particles are required for the infection of Creutzfeldt-Jakob disease (CJD). OBJECTIVE To determine the relationship between BK polyomavirus (BKV) and sporadic CJD. MATERIALS AND METHODS We investigated the prevalence of BKV in urine samples from 94 sporadic CJD patients and 54 other neurological disease (OND) patients using polymerase chain reaction. RESULTS BKV DNA was detected in 16 (17%) and 9 (16.7%) urine samples from sporadic CJD and OND patients, respectively. There was no significant difference in the incidence of BKV infection between Korean sporadic CJD and OND patients (p = 0.9558). In order to investigate the genotypes of BKV, we analyzed 22 BKV isolates obtained from Korean patients by DNA sequencing and nucleotide sequence analysis. Three distinct subtypes, namely I, III, and IV, were found in 66.7, 22.2, and 11.1% of 9 BKV isolates from OND patients, whereas subtypes I and IV were detected in 76.9 and 23.1% of 13 BKV isolates from sporadic CJD patients. Interestingly, subtype III was not detected in sporadic CJD patients. Significant differences in the frequency of BKV genotypes were not observed between sporadic CJD and OND patients. CONCLUSIONS These results indicate that BKV may not play an important role in the pathogenesis of prion diseases.
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Affiliation(s)
- Byung-Hoon Jeong
- Ilsong Institute of Life Science, Hallym University, Gyeonggi-do, Republic of Korea
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Krasemann S, Neumann M, Luepke JP, Grashorn J, Wurr S, Stocking C, Glatzel M. Persistent retroviral infection with MoMuLV influences neuropathological signature and phenotype of prion disease. Acta Neuropathol 2012; 124:111-26. [PMID: 22271154 DOI: 10.1007/s00401-012-0944-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 01/08/2012] [Accepted: 01/09/2012] [Indexed: 12/26/2022]
Abstract
A fundamental step in pathophysiology of prion diseases is the conversion of the host encoded prion protein (PrP(C)) into a misfolded isoform (PrP(Sc)) that accumulates mainly in neuronal but also non-neuronal tissues. Prion diseases are transmissible within and between species. In a subset of prion diseases, peripheral prion uptake and subsequent transport to the central nervous system are key to disease initiation. The involvement of retroviruses in this process has been postulated based on the findings that retroviral infections enhance the spread of prion infectivity and PrP(Sc) from cell to cell in vitro. To study whether retroviral infection influences the phenotype of prion disease or the spread of prion infectivity and PrP(Sc) in vivo, we developed a murine model with persistent Moloney murine leukemia retrovirus (MoMuLV) infection with and without additional prion infection. We investigated the pathophysiology of prion disease in MoMuLV and prion-infected mice, monitoring temporal kinetics of PrP(Sc) spread and prion infectivity, as well as clinical presentation. Unexpectedly, infection of MoMuLV challenged mice with prions did not change incubation time to clinical prion disease. However, clinical presentation of prion disease was altered in mice infected with both pathogens. This was paralleled by remarkably enhanced astrogliosis and pathognomonic astrocyte morphology in the brain of these mice. Therefore, we conclude that persistent viral infection might act as a disease modifier in prion disease.
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Affiliation(s)
- Susanne Krasemann
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
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Co-infection with the friend retrovirus and mouse scrapie does not alter prion disease pathogenesis in susceptible mice. PLoS One 2012; 7:e30872. [PMID: 22295118 PMCID: PMC3266293 DOI: 10.1371/journal.pone.0030872] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Accepted: 12/22/2011] [Indexed: 11/19/2022] Open
Abstract
Prion diseases are fatal, transmissible neurodegenerative diseases of the central nervous system. An abnormally protease-resistant and insoluble form (PrP(Sc)) of the normally soluble protease-sensitive host prion protein (PrP(C)) is the major component of the infectious prion. During the course of prion disease, PrP(Sc) accumulates primarily in the lymphoreticular and central nervous systems. Recent studies have shown that co-infection of prion-infected fibroblast cells with the Moloney murine leukemia virus (Mo-MuLV) strongly enhanced the release and spread of scrapie infectivity in cell culture, suggesting that retroviral coinfection might significantly influence prion spread and disease incubation times in vivo. We now show that another retrovirus, the murine leukemia virus Friend (F-MuLV), also enhanced the release and spread of scrapie infectivity in cell culture. However, peripheral co-infection of mice with both Friend virus and the mouse scrapie strain 22L did not alter scrapie disease incubation times, the levels of PrP(Sc) in the brain or spleen, or the distribution of pathological lesions in the brain. Thus, retroviral co-infection does not necessarily alter prion disease pathogenesis in vivo, most likely because of different cell-specific sites of replication for scrapie and F-MuLV.
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Greenwood AD, Vincendeau M, Schmädicke AC, Montag J, Seifarth W, Motzkus D. Bovine spongiform encephalopathy infection alters endogenous retrovirus expression in distinct brain regions of cynomolgus macaques (Macaca fascicularis). Mol Neurodegener 2011; 6:44. [PMID: 21699683 PMCID: PMC3152937 DOI: 10.1186/1750-1326-6-44] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 06/23/2011] [Indexed: 01/10/2023] Open
Abstract
Background Prion diseases such as bovine spongiform encephalopathies (BSE) are transmissible neurodegenerative diseases which are presumably caused by an infectious conformational isoform of the cellular prion protein. Previous work has provided evidence that in murine prion disease the endogenous retrovirus (ERV) expression is altered in the brain. To determine if prion-induced changes in ERV expression are a general phenomenon we used a non-human primate model for prion disease. Results Cynomolgus macaques (Macaca fasicularis) were infected intracerebrally with BSE-positive brain stem material from cattle and allowed to develop prion disease. Brain tissue from the basis pontis and vermis cerebelli of the six animals and the same regions from four healthy controls were subjected to ERV expression profiling using a retrovirus-specific microarray and quantitative real-time PCR. We could show that Class I gammaretroviruses HERV-E4-1, ERV-9, and MacERV-4 increase expression in BSE-infected macaques. In a second approach, we analysed ERV-K-(HML-2) RNA and protein expression in extracts from the same cynomolgus macaques. Here we found a significant downregulation of both, the macaque ERV-K-(HML-2) Gag protein and RNA in the frontal/parietal cortex of BSE-infected macaques. Conclusions We provide evidence that dysregulation of ERVs in response to BSE-infection can be detected on both, the RNA and the protein level. To our knowledge, this is the first report on the differential expression of ERV-derived structural proteins in prion disorders. Our findings suggest that endogenous retroviruses may induce or exacerbate the pathological consequences of prion-associated neurodegeneration.
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Affiliation(s)
- Alex D Greenwood
- German Primate Center, Leibniz-Institute for Primate Research, Unit of Infection Models, D-37077 Göttingen, Germany.
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The prevalence of human endogenous retroviruses in cerebrospinal fluids from patients with sporadic Creutzfeldt–Jakob disease. J Clin Virol 2010; 47:136-42. [DOI: 10.1016/j.jcv.2009.11.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 11/03/2009] [Accepted: 11/11/2009] [Indexed: 11/21/2022]
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Harrington RD, Herrmann-Hoesing LM, White SN, O'Rourke KI, Knowles DP. Ovine progressive pneumonia provirus levels are unaffected by the prion 171R allele in an Idaho sheep flock. Genet Sel Evol 2009; 41:17. [PMID: 19284685 PMCID: PMC3225825 DOI: 10.1186/1297-9686-41-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 01/22/2009] [Indexed: 11/10/2022] Open
Abstract
Selective breeding of sheep for arginine (R) at prion gene (PRNP) codon 171 confers resistance to classical scrapie. However, other effects of 171R selection are uncertain. Ovine progressive pneumonia/Maedi-Visna virus (OPPV) may infect up to 66% of a flock thus any affect of 171R selection on OPPV susceptibility or disease progression could have major impact on the sheep industry. Hypotheses that the PRNP 171R allele is 1) associated with the presence of OPPV provirus and 2) associated with higher provirus levels were tested in an Idaho ewe flock. OPPV provirus was found in 226 of 358 ewes by quantitative PCR. The frequency of ewes with detectable provirus did not differ significantly among the 171QQ, 171QR, and 171RR genotypes (p > 0.05). Also, OPPV provirus levels in infected ewes were not significantly different among codon 171 genotypes (p > 0.05). These results show that, in the flock examined, the presence of OPPV provirus and provirus levels are not related to the PRNP 171R allele. Therefore, a genetic approach to scrapie control is not expected to increase or decrease the number of OPPV infected sheep or the progression of disease. This study provides further support to the adoption of PRNP 171R selection as a scrapie control measure.
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Affiliation(s)
- Robert D Harrington
- Animal Disease Research Unit, Agricultural Research Service, US Department of Agriculture, Pullman, WA 99164-6630, USA.
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Gordon PMK, Schütz E, Beck J, Urnovitz HB, Graham C, Clark R, Dudas S, Czub S, Sensen M, Brenig B, Groschup MH, Church RB, Sensen CW. Disease-specific motifs can be identified in circulating nucleic acids from live elk and cattle infected with transmissible spongiform encephalopathies. Nucleic Acids Res 2008; 37:550-6. [PMID: 19059996 PMCID: PMC2632913 DOI: 10.1093/nar/gkn963] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
To gain insight into the disease progression of transmissible spongiform encephalopathies (TSE), we searched for disease-specific patterns in circulating nucleic acids (CNA) in elk and cattle. In a 25-month time-course experiment, CNAs were isolated from blood samples of 24 elk (Cervus elaphus) orally challenged with chronic wasting disease (CWD) infectious material. In a separate experiment, blood-sample CNAs from 29 experimental cattle (Bos taurus) 40 months post-inoculation with clinical bovine spongiform encephalopathy (BSE) were analyzed according to the same protocol. Next-generation sequencing provided broad elucidation of sample CNAs: we detected infection-specific sequences as early as 11 months in elk (i.e. at least 3 months before the appearance of the first clinical signs) and we established CNA patterns related to BSE in cattle at least 4 months prior to clinical signs. In elk, a progression of CNA sequence patterns was found to precede and correlate with macro-observable disease progression, including delayed CWD progression in elk with PrP genotype LM. Some of the patterns identified contain transcription-factor-binding sites linked to endogenous retroviral integration. These patterns suggest that retroviruses may be connected to the manifestation of TSEs. Our results may become useful for the early diagnosis of TSE in live elk and cattle.
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Affiliation(s)
- Paul M K Gordon
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Sun Center of Excellence for Visual Genomics, University of Calgary, Calgary, AB, Canada T2N 4N1
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Kim BH, Meeker HC, Shin HY, Kim JI, Jeong BH, Choi EK, Carp RI, Kim YS. Physiological properties of astroglial cell lines derived from mice with high (SAMP8) and low (SAMR1, ICR) levels of endogenous retrovirus. Retrovirology 2008; 5:104. [PMID: 19032740 PMCID: PMC2607306 DOI: 10.1186/1742-4690-5-104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2008] [Accepted: 11/25/2008] [Indexed: 11/10/2022] Open
Abstract
Previous studies have reported that various inbred SAM mouse strains differ markedly with regard to a variety of parameters, such as capacity for learning and memory, life spans and brain histopathology. A potential cause of differences seen in these strains may be based on the fact that some strains have a high concentration of infectious murine leukemia virus (MuLV) in the brain, whereas other strains have little or no virus. To elucidate the effect of a higher titer of endogenous retrovirus in astroglial cells of the brain, we established astroglial cell lines from SAMR1 and SAMP8 mice, which are, respectively, resistant and prone to deficit in learning and memory and shortened life span. MuLV-negative astroglial cell lines established from ICR mice served as controls. Comparison of these cell lines showed differences in: 1) levels of the capsid antigen CAgag in both cell lysates and culture media, 2) expression of genomic retroelements, 3) the number of virus particles, 4) titer of infectious virus, 5) morphology, 6) replication rate of cells in culture and final cell concentrations, 7) expression pattern of proinflammatory cytokine genes. The results show that the expression of MuLV is much higher in SAMP8 than SAMR1 astrocyte cultures and that there are physiological differences in astroglia from the 2 strains. These results raise the possibility that the distinct physiological differences between SAMP8 and SAMR1 are a function of activation of endogenous retrovirus.
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Affiliation(s)
- Boe-Hyun Kim
- Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong Dongan-gu, Anyang, Gyeonggi-do 431-060, South Korea.
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The effect of Fenton reaction on protease-resistant prion protein (PrPSc) degradation and scrapie infectivity. Brain Res 2008; 1238:172-80. [DOI: 10.1016/j.brainres.2008.07.117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 07/30/2008] [Accepted: 07/30/2008] [Indexed: 11/17/2022]
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Small-ruminant lentivirus enhances PrPSc accumulation in cultured sheep microglial cells. J Virol 2008; 82:9839-47. [PMID: 18684809 DOI: 10.1128/jvi.01137-08] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sheep scrapie is the prototypical transmissible spongiform encephalopathy (prion disease), which has a fundamental pathogenesis involving conversion of normal cellular prion protein (PrP(C) [C superscript stands for cellular]) to disease-associated prion protein (PrP(Sc) [Sc superscript stands for sheep scrapie]). Sheep microglial cell cultures, derived from a prnp 136VV/171QQ near-term fetal brain, were developed to study sheep scrapie in the natural host and to investigate potential cofactors in the prion conversion process. Two culture systems, a primary cell culture and a cell line transformed with the large T antigen of simian virus 40, were developed, and both were identified as microglial in origin as indicated by expression of several microglial phenotype markers. Following exposure to PrP(Sc), sheep microglial cells demonstrated relatively low levels (transformed cell line) to high levels (primary cell line) of PrP(Sc) accumulation over time. The accumulated PrP(Sc) demonstrated protease resistance, an inferred beta-sheet conformation (as determined by a commercial enzyme-linked immunosorbent assay), specific inhibition by anti-PrP antibodies, and was transmissible in a dose-dependent manner. Primary microglia coinfected with a small-ruminant lentivirus (caprine arthritis encephalitis virus-Cork strain) and PrP(Sc) demonstrated an approximately twofold increase in PrP(Sc) accumulation compared to that of primary microglia infected with PrP(Sc) alone. The results demonstrate the in vitro utility of PrP(Sc)-permissive sheep microglial cells in investigating the biology of natural prion diseases and show that small-ruminant lentiviruses enhance prion conversion in cultured sheep microglia.
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Induced prion protein controls immune-activated retroviruses in the mouse spleen. PLoS One 2007; 2:e1158. [PMID: 17987132 PMCID: PMC2063463 DOI: 10.1371/journal.pone.0001158] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Accepted: 10/16/2007] [Indexed: 01/18/2023] Open
Abstract
The prion protein (PrP) is crucially involved in transmissible spongiform encephalopathies (TSE), but neither its exact role in disease nor its physiological function are known. Here we show for mice, using histological, immunochemical and PCR-based methods, that stimulation of innate resistance was followed by appearance of numerous endogenous retroviruses and ensuing PrP up-regulation in germinal centers of the spleen. Subsequently, the activated retroviruses disappeared in a PrP-dependent manner. Our results reveal the regular involvement of endogenous retroviruses in murine immune responses and provide evidence for an essential function of PrP in the control of the retroviral activity. The interaction between PrP and ubiquitous endogenous retroviruses may allow new interpretations of TSE pathophysiology and explain the evolutionary conservation of PrP.
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