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Li R, Wang Z, Liu C, Qiao W, Tan J. Effects of Chemokine Ligand 2 on Budding of Bovine Foamy Virus. Viruses 2023; 15:1867. [PMID: 37766274 PMCID: PMC10536199 DOI: 10.3390/v15091867] [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] [Received: 05/25/2023] [Revised: 08/25/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023] Open
Abstract
The endosomal sorting complex required for transport (ESCRT) machinery is essential for the budding of retroviruses such as human immunodeficiency virus (HIV) and bovine foamy virus (BFV), which rely on their late domain to recruit ESCRT complexes to facilitate budding. However, the impact of intracellular host proteins on BFV budding remains poorly understood. In this study, we aimed to investigate the impact of CCL2 on BFV budding and interactions with key host proteins. Our results indicate that CCL2 promotes BFV budding in an ALG-2-interacting protein X (Alix)-dependent manner by enhancing the interaction between Alix and BFV Gag (BGag). Notably, we found a link between Alix, BGag and CCL2, with Alix mediating the interaction between the latter two. Furthermore, we observed that natural host bovine CCL2 also has a facilitating role in the budding process of BFV, similar to human CCL2. Taken together, these results demonstrate that CCL2 promotes BFV budding by enhancing the Alix-BGag association.
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Affiliation(s)
| | | | | | | | - Juan Tan
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China; (R.L.); (Z.W.); (C.L.); (W.Q.)
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2
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Materniak-Kornas M, Kubiś P, Sell B, Pougialis G, Löchelt M, Kuźmak J. An Outbred Calf Model for Determining Innate Immune Sensing and Evolutionary Trajectories of a Cell Culture-Adapted Bovine Foamy Virus Variant. Viruses 2023; 15:1772. [PMID: 37632114 PMCID: PMC10458543 DOI: 10.3390/v15081772] [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] [Received: 06/30/2023] [Revised: 08/10/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
Bovine foamy virus (BFVbta) displays a very high degree of cell-associated replication which is unprecedented even among the other known foamy viruses. Interestingly, recent studies have shown that it can in fact adapt in vitro to high-titer (HT) cell-free transmission due to genetic changes acquired during repeated rounds of cell-free BFVbta passages in immortalized bovine MDBK cells. Molecular clones obtained from the HT BFVbta Riems cell-free variant (HT BFVbta Riems) have been thoroughly characterized in MDBK cell cultures However, during recent years, it has become increasingly clear that the source of the host cells used for virus growth and functional studies of virus replication and virus-cell interactions plays a paramount role. Established cell lines, mostly derived from tumors, but occasionally experimentally immortalized and transformed, frequently display aberrant features relating, for example. to growth, metabolism, and genetics. Even state-of-the-art organoid cultures of primary cells cannot replicate the conditions in an authentic host, especially those concerning cell diversity and the role of innate and adaptive immunity. Therefore, to determine the overall replication characteristics of the cloned wt and HT BFVbta Riems variant, we conducted a small-scale animal pilot study. The replication of the original wt BFVbta Riems isolate, as well as that of its HT variant, were analyzed. Both BFVbta variants established infection in calves, with proviruses in peripheral blood mononuclear cells and induced Gag-specific antibodies. In addition, a related pattern in the host innate immune reaction was detected in the peripheral blood leukocytes of the BFV-infected calves. Surprisingly, an analysis of the Gag sequence two weeks post-inoculation revealed that the HT BFVbta variant showed a very high level of genetic reversion to the wild type (parental BFVbta genotype).
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Affiliation(s)
- Magdalena Materniak-Kornas
- Department of Biochemistry, National Veterinary Research Institute, 24-100 Pulawy, Poland; (P.K.); (J.K.)
| | - Piotr Kubiś
- Department of Biochemistry, National Veterinary Research Institute, 24-100 Pulawy, Poland; (P.K.); (J.K.)
| | - Bartosz Sell
- Department of Pharmacology and Toxicology, National Veterinary Research Institute, 24-100 Pulawy, Poland;
| | - Georgios Pougialis
- Division of Viral Transformation Mechanisms, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, 69120 Heidelberg, Germany; (G.P.); (M.L.)
| | - Martin Löchelt
- Division of Viral Transformation Mechanisms, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, 69120 Heidelberg, Germany; (G.P.); (M.L.)
- Division of Virus-Associated Carcinogenesis, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Jacek Kuźmak
- Department of Biochemistry, National Veterinary Research Institute, 24-100 Pulawy, Poland; (P.K.); (J.K.)
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Molecular Epidemiology and Whole-Genome Analysis of Bovine Foamy Virus in Japan. Viruses 2021; 13:v13061017. [PMID: 34071542 PMCID: PMC8230093 DOI: 10.3390/v13061017] [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: 04/23/2021] [Revised: 05/26/2021] [Accepted: 05/26/2021] [Indexed: 11/17/2022] Open
Abstract
Bovine foamy virus (BFV) is a member of the foamy virus family in cattle. Information on the epidemiology, transmission routes, and whole-genome sequences of BFV is still limited. To understand the characteristics of BFV, this study included a molecular survey in Japan and the determination of the whole-genome sequences of 30 BFV isolates. A total of 30 (3.4%, 30/884) cattle were infected with BFV according to PCR analysis. Cattle less than 48 months old were scarcely infected with this virus, and older animals had a significantly higher rate of infection. To reveal the possibility of vertical transmission, we additionally surveyed 77 pairs of dams and 3-month-old calves in a farm already confirmed to have BFV. We confirmed that one of the calves born from a dam with BFV was infected. Phylogenetic analyses revealed that a novel genotype was spread in Japan. In conclusion, the prevalence of BFV in Japan is relatively low and three genotypes, including a novel genotype, are spread in Japan.
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The Unique, the Known, and the Unknown of Spumaretrovirus Assembly. Viruses 2021; 13:v13010105. [PMID: 33451128 PMCID: PMC7828637 DOI: 10.3390/v13010105] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/08/2021] [Accepted: 01/10/2021] [Indexed: 12/22/2022] Open
Abstract
Within the family of Retroviridae, foamy viruses (FVs) are unique and unconventional with respect to many aspects in their molecular biology, including assembly and release of enveloped viral particles. Both components of the minimal assembly and release machinery, Gag and Env, display significant differences in their molecular structures and functions compared to the other retroviruses. This led to the placement of FVs into a separate subfamily, the Spumaretrovirinae. Here, we describe the molecular differences in FV Gag and Env, as well as Pol, which is translated as a separate protein and not in an orthoretroviral manner as a Gag-Pol fusion protein. This feature further complicates FV assembly since a specialized Pol encapsidation strategy via a tripartite Gag-genome–Pol complex is used. We try to relate the different features and specific interaction patterns of the FV Gag, Pol, and Env proteins in order to develop a comprehensive and dynamic picture of particle assembly and release, but also other features that are indirectly affected. Since FVs are at the root of the retrovirus tree, we aim at dissecting the unique/specialized features from those shared among the Spuma- and Orthoretrovirinae. Such analyses may shed light on the evolution and characteristics of virus envelopment since related viruses within the Ortervirales, for instance LTR retrotransposons, are characterized by different levels of envelopment, thus affecting the capacity for intercellular transmission.
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Functional Analyses of Bovine Foamy Virus-Encoded miRNAs Reveal the Importance of a Defined miRNA for Virus Replication and Host-Virus Interaction. Viruses 2020; 12:v12111250. [PMID: 33147813 PMCID: PMC7693620 DOI: 10.3390/v12111250] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/22/2020] [Accepted: 10/27/2020] [Indexed: 12/19/2022] Open
Abstract
In addition to regulatory or accessory proteins, some complex retroviruses gain a repertoire of micro-RNAs (miRNAs) to regulate and control virus–host interactions for efficient replication and spread. In particular, bovine and simian foamy viruses (BFV and SFV) have recently been shown to express a diverse set of RNA polymerase III-directed miRNAs, some with a unique primary miRNA double-hairpin, dumbbell-shaped structure not known in other viruses or organisms. While the mechanisms of expression and structural requirements have been studied, the functional importance of these miRNAs is still far from understood. Here, we describe the in silico identification of BFV miRNA targets and the subsequent experimental validation of bovine Ankyrin Repeat Domain 17 (ANKRD17) and Bax-interacting factor 1 (Bif1) target genes in vitro and, finally, the suppression of ANKRD17 downstream genes in the affected pathway. Deletion of the entire miRNA cassette in the non-coding part of the U3 region of the long terminal repeats attenuated replication of corresponding BFV mutants in bovine cells. This repression can be almost completely trans-complemented by the most abundant miRNA BF2-5p having the best scores for predicted and validated BFV miRNA target genes. Deletion of the miRNA cassette does not grossly affect particle release and overall particle composition.
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Okamoto M, Oguma K, Yamashita-Kawanishi N, Ichijo T, Hatama S, Endo M, Ishikawa M, Haga T. Genomic characterization and distribution of bovine foamy virus in Japan. J Vet Med Sci 2020; 82:1607-1613. [PMID: 32921656 PMCID: PMC7719878 DOI: 10.1292/jvms.20-0429] [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] [Indexed: 01/22/2023] Open
Abstract
Bovine foamy virus (BFV) is distributed through worldwide cattle herds. Although the biological features of BFV are not well understood, appearance of clinical
manifestation by superinfection with other microorganisms is inferred. In Japan, reports of genomic characterizations and epidemiology of this virus are
limited. In this study, we performed whole genomic sequencing of BFV strains Ibaraki and No.43, which were isolated in this country. Additionally, we
investigated BFV in geographically distant four daily farms in Japan, to estimate the distribution of BFV and its correlation to bovine leukemia virus (BLV).
BFV was distributed throughout Japan; the average positive rate was 12.7%. The nucleotide sequence identities of the isolates were 99.6% when compared with BFV
strain isolated in the USA. The phylogenetic tree using env gene sequence showed strains Ibaraki, No.43 and Kagoshima were sorted in the same
cluster including the USA and Chinese strains, while Hokkaido strain was in the other cluster including European strains. Although no clear correlation between
BFV and BLV could be found, BFV and BLV infections were likely to increase with ages. Our data on epidemiology and characteristics of BFV will provide important
information to reveal biological features of BFV.
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Affiliation(s)
- Mari Okamoto
- Division of Infection Control and Disease Prevention, Department of Veterinary Medical Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Keisuke Oguma
- Laboratory of Veterinary Epizootiology, Department of Veterinary Medicine, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Nanako Yamashita-Kawanishi
- Division of Infection Control and Disease Prevention, Department of Veterinary Medical Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Toshihiro Ichijo
- Iwate University Faculty of Agriculture Veterinary Medicine, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan
| | - Shinichi Hatama
- National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan
| | - Maiko Endo
- Animal Resource Science Center, Graduate School of Agricultural and Life Science, The University of Tokyo, 3145 Yorii, Kasama, Ibaraki 319-0206, Japan
| | - Maya Ishikawa
- Private investigator, Izumimachi, Shikaoi, Katogun, Hokkaido 081-0212, Japan
| | - Takeshi Haga
- Division of Infection Control and Disease Prevention, Department of Veterinary Medical Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Iwasaki R, Nakagiri Y, Yaguchi Y, Oguma K, Ono M, Horikita T, Sentsui H. Survey of bovine foamy virus infection among cattle in Japan and comparison with bovine leukemia virus infection. J Vet Med Sci 2020; 82:615-618. [PMID: 32201403 PMCID: PMC7273609 DOI: 10.1292/jvms.19-0592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The prevalence of bovine foamy virus (BFV) infections in cattle on farms in the Kanto region of Japan was determined using agar gel immunodiffusion (AGID) test and polymerase chain reaction
(PCR). Six out of 20 farms contained BFV-positive cattle. Furthermore, 16.7% (91/545) of all cattle tested positive for BFV. This suggested that BFV-infected cattle are widely prevalent in
Japan. Positive results for BFV infection were consistent between AGID and PCR tests. Additionally, we tested for bovine leukemia virus (BLV) infections at nine farms, primarily those
containing BFV-infected cows. At each farm, the infection rate of BFV was lower than that of BLV. Further, cattle that were PCR-positive but antibody-negative, indicating immune tolerance to
BFV, were not detected.
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Affiliation(s)
- Ryoji Iwasaki
- Laboratory of Veterinary Epizootiology, Department of Veterinary Medicine, Nihon University, Kameino 1866, Fujisawa, Kanagawa 252-0880, Japan
| | - Yu Nakagiri
- Laboratory of Veterinary Epizootiology, Department of Veterinary Medicine, Nihon University, Kameino 1866, Fujisawa, Kanagawa 252-0880, Japan
| | - Yuji Yaguchi
- Ibaraki Kenhoku Animal Hygiene Service Station, Nakakawauchi 966-1, Mito, Ibaraki 310-0002, Japan
| | - Keisuke Oguma
- Laboratory of Veterinary Epizootiology, Department of Veterinary Medicine, Nihon University, Kameino 1866, Fujisawa, Kanagawa 252-0880, Japan
| | - Mamiko Ono
- Laboratory of Large Animal Clinical Sciences, Department of Veterinary Medicine, Nihon University, Kameino 1866, Fujisawa, Kanagawa 252-0880, Japan
| | - Tetsuya Horikita
- Laboratory of Large Animal Clinical Sciences, Department of Veterinary Medicine, Nihon University, Kameino 1866, Fujisawa, Kanagawa 252-0880, Japan
| | - Hiroshi Sentsui
- Laboratory of Veterinary Epizootiology, Department of Veterinary Medicine, Nihon University, Kameino 1866, Fujisawa, Kanagawa 252-0880, Japan
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Bao Q, Hotz-Wagenblatt A, Betts MJ, Hipp M, Hugo A, Pougialis G, Lei-Rossmann J, Löchelt M. Shared and cell type-specific adaptation strategies of Gag and Env yield high titer bovine foamy virus variants. INFECTION GENETICS AND EVOLUTION 2020; 82:104287. [PMID: 32179148 DOI: 10.1016/j.meegid.2020.104287] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 03/05/2020] [Accepted: 03/11/2020] [Indexed: 12/27/2022]
Abstract
During in vitro selection and evolution screens to adapt the tightly cell-associated bovine foamy virus BFV to high titer cell-free transmission, common, cell-type specific and concurrent adaptive changes in Gag and Env, the major players of foamy virus particle assembly and release, were detected. Upon early establishment of cell type-independent pioneering mutations in Env and, subsequently in Gag, a diverse virus pool emerged that was characterized by the occurrence of shared and additional cell type-specific exchanges. At late passages and saturated titers, remarkably homogeneous virus populations characterized by functionally important mutations developed which may be partly due to stochastic evolutionary events that occurred earlier during adaptation. Reverse genetics showed that defined mutations were functionally important for high titer cell-free transmission.
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Affiliation(s)
- Qiuying Bao
- Division of Viral Transformation Mechanisms, Research Focus Infection, Inflammation and Cancer, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany.
| | | | - Matthew J Betts
- CellNetworks, Bioquant, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany.
| | - Michaela Hipp
- Division of Viral Transformation Mechanisms, Research Focus Infection, Inflammation and Cancer, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany.
| | - Annette Hugo
- Division of Viral Transformation Mechanisms, Research Focus Infection, Inflammation and Cancer, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany.
| | - Georgios Pougialis
- Division of Viral Transformation Mechanisms, Research Focus Infection, Inflammation and Cancer, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany.
| | - Janet Lei-Rossmann
- Division of Viral Transformation Mechanisms, Research Focus Infection, Inflammation and Cancer, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany.
| | - Martin Löchelt
- Division of Viral Transformation Mechanisms, Research Focus Infection, Inflammation and Cancer, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany.
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Materniak-Kornas M, Tan J, Heit-Mondrzyk A, Hotz-Wagenblatt A, Löchelt M. Bovine Foamy Virus: Shared and Unique Molecular Features In Vitro and In Vivo. Viruses 2019; 11:E1084. [PMID: 31766538 PMCID: PMC6950176 DOI: 10.3390/v11121084] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/18/2019] [Accepted: 11/19/2019] [Indexed: 12/18/2022] Open
Abstract
The retroviral subfamily of Spumaretrovirinae consists of five genera of foamy (spuma) viruses (FVs) that are endemic in some mammalian hosts [1]. Closely related species may be susceptible to the same or highly related FVs. FVs are not known to induce overt disease and thus do not pose medical problems to humans and livestock or companion animals. A robust lab animal model is not available or is a lab animal a natural host of a FV. Due to this, research is limited and often focused on the simian FVs with their well-established zoonotic potential. The authors of this review and their groups have conducted several studies on bovine FV (BFV) in the past with the intention of (i) exploring the risk of zoonotic infection via beef and raw cattle products, (ii) studying a co-factorial role of BFV in different cattle diseases with unclear etiology, (iii) exploring unique features of FV molecular biology and replication strategies in non-simian FVs, and (iv) conducting animal studies and functional virology in BFV-infected calves as a model for corresponding studies in primates or small lab animals. These studies gained new insights into FV-host interactions, mechanisms of gene expression, and transcriptional regulation, including miRNA biology, host-directed restriction of FV replication, spread and distribution in the infected animal, and at the population level. The current review attempts to summarize these findings in BFV and tries to connect them to findings from other FVs.
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Affiliation(s)
| | - Juan Tan
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China;
| | - Anke Heit-Mondrzyk
- German Cancer Research Center DKFZ, Core Facility Omics IT and Data Management, 69120 Heidelberg, Germany; (A.H.-M.); (A.H.-W.)
| | - Agnes Hotz-Wagenblatt
- German Cancer Research Center DKFZ, Core Facility Omics IT and Data Management, 69120 Heidelberg, Germany; (A.H.-M.); (A.H.-W.)
| | - Martin Löchelt
- German Cancer Research Center DKFZ, Program Infection, Inflammation and Cancer, Div. Viral Transformation Mechanisms, 69120 Heidelberg, Germany
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Isolation of an Equine Foamy Virus and Sero-Epidemiology of the Viral Infection in Horses in Japan. Viruses 2019; 11:v11070613. [PMID: 31284407 PMCID: PMC6669534 DOI: 10.3390/v11070613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 11/16/2022] Open
Abstract
An equine foamy virus (EFV) was isolated for the first time in Japan from peripheral blood mononuclear cells of a broodmare that showed wobbler syndrome after surgery for intestinal volvulus and the isolate was designated as EFVeca_LM. Complete nucleotide sequences of EFVeca_LM were determined. Nucleotide sequence analysis of the long terminal repeat (LTR) region, gag, pol, env, tas, and bel2 genes revealed that EFVeca_LM and the EFV reference strain had 97.2% to 99.1% identities. For a sero-epidemiological survey, indirect immunofluorescent antibody tests were carried out using EFVeca_LM-infected cells as an antigen against 166 sera of horses in five farms collected in 2001 to 2002 and 293 sera of horses in eight farms collected in 2014 to 2016 in Hokkaido, Japan. All of the farms had EFV antibody-positive horses, and average positive rates were 24.6% in sera obtained in 2001 to 2002 and 25.6% in sera obtained in 2014 to 2016 from broodmare farms. The positive rate in a stallion farm (Farm A) in 2002 was 10.7%, and the positive rates in two stallion farms, Farms A and B, in 2015 were 40.9% and 13.3%, respectively. The results suggested that EFV infection is maintained widely in horses in Japan.
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The Influence of Envelope C-Terminus Amino Acid Composition on the Ratio of Cell-Free to Cell-Cell Transmission for Bovine Foamy Virus. Viruses 2019; 11:v11020130. [PMID: 30708993 PMCID: PMC6410131 DOI: 10.3390/v11020130] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 01/26/2019] [Accepted: 01/29/2019] [Indexed: 12/13/2022] Open
Abstract
Foamy viruses (FVs) have extensive cell tropism in vitro, special replication features, and no clinical pathogenicity in naturally or experimentally infected animals, which distinguish them from orthoretroviruses. Among FVs, bovine foamy virus (BFV) has undetectable or extremely low levels of cell-free transmission in the supernatants of infected cells and mainly spreads by cell-to-cell transmission, which deters its use as a gene transfer vector. Here, using an in vitro virus evolution system, we successfully isolated high-titer cell-free BFV strains from the original cell-to-cell transmissible BFV3026 strain and further constructed an infectious cell-free BFV clone called pBS-BFV-Z1. Following sequence alignment with a cell-associated clone pBS-BFV-B, we identified a number of changes in the genome of pBS-BFV-Z1. Extensive mutagenesis analysis revealed that the C-terminus of envelope protein, especially the K898 residue, controls BFV cell-free transmission by enhancing cell-free virus entry but not the virus release capacity. Taken together, our data show the genetic determinants that regulate cell-to-cell and cell-free transmission of BFV.
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12
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Cao W, Heit A, Hotz-Wagenblatt A, Löchelt M. Functional characterization of the bovine foamy virus miRNA expression cassette and its dumbbell-shaped pri-miRNA. Virus Genes 2018; 54:550-560. [PMID: 29855776 DOI: 10.1007/s11262-018-1574-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 05/19/2018] [Indexed: 12/21/2022]
Abstract
Foamy viruses are unconventional and complex retroviruses distinct from the other members of the Retroviridae family. Currently, no disease has been firmly linked to persistent foamy virus infection of their cognate host including simians, bovines, felines, and equines or upon zoonotic transmission of different simian foamy viruses to humans. Bovine and simian foamy viruses have been recently shown to encode a RNA polymerase-III-driven micro RNA cluster which likely modulates and regulates host-virus interactions at different levels. Using sub-genomic bovine foamy virus micro RNA expression plasmids and dual luciferase reporter assays as readout, the requirements for expression and processing of the bovine foamy virus micro RNAs have been analyzed. Here, we report that the minimal BFV micro RNA cassette is significantly weaker than a U6 promoter-based construct and strongly suppressed by flanking sequences. The primary micro RNA sequence can be manipulated and chimerized as long as the dumbbell-like folding of the primary micro RNA is maintained. Since more subtle changes are associated with reduced functionality, the overall structure and shape, but possibly individual elements and residues also, are important for the expression and processing of the bovine foamy virus micro RNAs.
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Affiliation(s)
- Wenhu Cao
- Division Molecular Diagnostics of Oncogenic Infections, Research Focus Infection, Inflammation and Cancer, Heidelberg, Germany
| | - Anke Heit
- Core Facility Omics IT and Data Management, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany
| | - Agnes Hotz-Wagenblatt
- Core Facility Omics IT and Data Management, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), Heidelberg, Germany
| | - Martin Löchelt
- Division Molecular Diagnostics of Oncogenic Infections, Research Focus Infection, Inflammation and Cancer, Heidelberg, Germany.
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13
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Buseyne F, Gessain A, Soares MA, Santos AF, Materniak-Kornas M, Lesage P, Zamborlini A, Löchelt M, Qiao W, Lindemann D, Wöhrl BM, Stoye JP, Taylor IA, Khan AS. Eleventh International Foamy Virus Conference-Meeting Report. Viruses 2016; 8:v8110318. [PMID: 27886074 PMCID: PMC5127032 DOI: 10.3390/v8110318] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 11/08/2016] [Accepted: 11/10/2016] [Indexed: 12/11/2022] Open
Abstract
The Eleventh International Foamy Virus Conference took place on 9–10 June 2016 at the Institut Pasteur, Paris, France. The meeting reviewed progress on foamy virus (FV) research, as well as related current topics in retrovirology. FVs are complex retroviruses that are widespread in several animal species. Several research topics on these viruses are relevant to human health: cross-species transmission and viral emergence, vectors for gene therapy, development of antiretroviral drugs, retroviral evolution and its influence on the human genome. In this article, we review the conference presentations on these viruses and highlight the major questions to be answered.
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Affiliation(s)
- Florence Buseyne
- Unité d'Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, 75015 Paris, France.
- Centre National de la Recherche Scientifique (CNRS), UMR3569, 75015 Paris, France.
| | - Antoine Gessain
- Unité d'Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, 75015 Paris, France.
- Centre National de la Recherche Scientifique (CNRS), UMR3569, 75015 Paris, France.
| | - Marcelo A Soares
- Department of Genetics, Universidade Federal do Rio de Janeiro, 21949-570 Rio de Janeiro, Brazil.
- Oncovirology Program, Instituto Nacional de Câncer, 20231-050 Rio de Janeiro, Brazil.
| | - André F Santos
- Department of Genetics, Universidade Federal do Rio de Janeiro, 21949-570 Rio de Janeiro, Brazil.
| | | | - Pascale Lesage
- Institut Universitaire d'Hématologie, Hôpital Saint-Louis, Université Paris Diderot, Sorbonne Paris Cité, INSERM U944, CNRS UMR 7212, 75010 Paris, France.
| | - Alessia Zamborlini
- Institut Universitaire d'Hématologie, Hôpital Saint-Louis, Université Paris Diderot, Sorbonne Paris Cité, INSERM U944, CNRS UMR 7212, 75010 Paris, France.
- Conservatoire National des Arts et Métiers, Laboratoire de Pathologie et Virologie Moléculaire, 75003 Paris, France.
| | - Martin Löchelt
- Department of Molecular Diagnostics of Oncogenic Infections, Research Program Infection, Inflammation and Cancer, 69120 Heidelberg, Germany.
| | - Wentao Qiao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China.
| | - Dirk Lindemann
- Institute of Virology, Medical Faculty "Carl Gustav Carus", Technische Universität Dresden, 01307 Dresden, Germany.
| | - Birgitta M Wöhrl
- University of Bayreuth, Department of Biopolymers, 95447 Bayreuth, Germany.
| | | | | | - Arifa S Khan
- Laboratory of Retroviruses, Division of Viral Products, OVRR, CBER, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
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