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Alimentary Pharmacology & Therapeutics Mar 2015
Topics: Betaretrovirus; Female; Hepatitis, Autoimmune; Hepatocytes; Humans; Liver Cirrhosis, Biliary; Male
PubMed: 25631652
DOI: 10.1111/apt.13082 -
Veterinary Medicine and Science May 2022Retroviral infections have been reported in many species of animals, especially cattle, sheep and goats. However, there are no available reports about retrovirus...
BACKGROUND
Retroviral infections have been reported in many species of animals, especially cattle, sheep and goats. However, there are no available reports about retrovirus infection in dromedary camels. Several dromedary camels showed visible tumor-like lesions on and around the nostrils as well as around the eyes.
OBJECTIVES
Following are the objectives: to identify the causative agents of these identified tumours in dromedary camels and to perform molecular characterization of the detected strains of the causative agent.
METHODS
We extracted the nucleic acids from some fresh lesions out of these animals, and then amplified some key retrovirus genes. We amplified several regions of the rotavirus genome using the PCR technique. The obtained sequences were assembled and the phylogenetic trees were conducted per each target retrovirus gene.
RESULTS
Our results revealed a high degree of identity to some retroviruses of sheep. Phylogenetic analysis based on some retrovirus genes revealed that the causative agents of these lesions are closely related to sheep retroviruses, particularly the Jaagsiekte sheep Retrovirus (JSRV) and the ENTV.
CONCLUSIONS
To the best of our knowledge, this is the first report of retrovirus infections in dromedary camels in the Arabian Peninsula. This highlights the possible species jump for the retrovirus from sheep and goats to the dromedary camels, which live in close proximity with these animals in many parts of the world, especially the Arabian Peninsula.
Topics: Animals; Betaretrovirus; Camelus; Cattle; Cattle Diseases; Goat Diseases; Goats; Phylogeny; Retroviridae Infections; Saudi Arabia; Sheep; Sheep Diseases
PubMed: 35114072
DOI: 10.1002/vms3.760 -
PLoS Genetics Apr 2021Acquisition of genetic material from viruses by their hosts can generate inter-host structural genome variation. We developed computational tools enabling us to study...
Acquisition of genetic material from viruses by their hosts can generate inter-host structural genome variation. We developed computational tools enabling us to study virus-derived structural variants (SVs) in population-scale whole genome sequencing (WGS) datasets and applied them to 3,332 humans. Although SVs had already been cataloged in these subjects, we found previously-overlooked virus-derived SVs. We detected non-germline SVs derived from squirrel monkey retrovirus (SMRV), human immunodeficiency virus 1 (HIV-1), and human T lymphotropic virus (HTLV-1); these variants are attributable to infection of the sequenced lymphoblastoid cell lines (LCLs) or their progenitor cells and may impact gene expression results and the biosafety of experiments using these cells. In addition, we detected new heritable SVs derived from human herpesvirus 6 (HHV-6) and human endogenous retrovirus-K (HERV-K). We report the first solo-direct repeat (DR) HHV-6 likely to reflect DR rearrangement of a known full-length endogenous HHV-6. We used linkage disequilibrium between single nucleotide variants (SNVs) and variants in reads that align to HERV-K, which often cannot be mapped uniquely using conventional short-read sequencing analysis methods, to locate previously-unknown polymorphic HERV-K loci. Some of these loci are tightly linked to trait-associated SNVs, some are in complex genome regions inaccessible by prior methods, and some contain novel HERV-K haplotypes likely derived from gene conversion from an unknown source or introgression. These tools and results broaden our perspective on the coevolution between viruses and humans, including ongoing virus-to-human gene transfer contributing to genetic variation between humans.
Topics: Betaretrovirus; Cell Line; Endogenous Retroviruses; Gene Expression Regulation; Genome, Human; Genomic Structural Variation; HIV-1; Herpesvirus 6, Human; Host-Pathogen Interactions; Human T-lymphotropic virus 1; Humans; Linkage Disequilibrium; Polymorphism, Single Nucleotide; Viruses; Whole Genome Sequencing
PubMed: 33901175
DOI: 10.1371/journal.pgen.1009324 -
Journal of Virology Jan 2022The surface envelope glycoproteins of nonprimate lentiviruses and betaretroviruses share sequence similarity with the inner proximal domain β-sandwich of the human...
The surface envelope glycoproteins of nonprimate lentiviruses and betaretroviruses share sequence similarity with the inner proximal domain β-sandwich of the human immunodeficiency virus type 1 (HIV-1) gp120 glycoprotein that faces the transmembrane glycoprotein as well as patterns of cysteine and glycosylation site distribution that points to a similar two-domain organization in at least some lentiviruses. Here, high-reliability models of the surface glycoproteins obtained with the AlphaFold algorithm are presented for the gp135 glycoprotein of the small ruminant caprine arthritis-encephalitis (CAEV) and visna lentiviruses and the betaretroviruses Jaagsiekte sheep retrovirus (JSRV), mouse mammary tumor virus (MMTV), and consensus human endogenous retrovirus type K (HERV-K). The models confirm and extend the inner domain structural conservation in these viruses and identify two outer domains with a putative receptor binding site in the CAEV and visna virus gp135. The location of that site is consistent with patterns of sequence conservation and glycosylation site distribution in gp135. In contrast, a single domain is modeled for the JSRV, MMTV, and HERV-K betaretrovirus envelope proteins that is highly conserved structurally in the proximal region and structurally diverse in apical regions likely to interact with cell receptors. The models presented here identify sites in small ruminant lentivirus and betaretrovirus envelope glycoproteins likely to be critical for virus entry and virus neutralization by antibodies and will facilitate their functional and structural characterization. Structural information on the surface envelope proteins of lentiviruses and related betaretroviruses is critical to understand mechanisms of virus-host interactions. However, experimental determination of these structures has been challenging, and only the structure of the human immunodeficiency virus type 1 gp120 has been determined. The advent of the AlphaFold artificial intelligence method for structure prediction allows high-quality modeling of the structures of small ruminant lentiviral and betaretroviral surface envelope proteins. The models are consistent with much of the previously described experimental data, show regions likely to interact with receptors, and identify domains that may be involved in mechanisms of antibody neutralization resistance in the small ruminant lentiviruses. The models will allow more precise design of mutants to further determine mechanisms of viral entry and immune evasion in this group of viruses and constructs for structural determination of these surface envelope proteins.
Topics: Algorithms; Amino Acid Sequence; Animals; Betaretrovirus; Binding Sites; Conserved Sequence; Endogenous Retroviruses; Gene Products, env; Humans; Lentivirus; Models, Molecular; Protein Binding; Protein Domains; Receptors, Virus; Ruminants
PubMed: 34705555
DOI: 10.1128/JVI.01348-21 -
American Journal of Reproductive... Oct 2010Endogenous retroviruses (ERVs) are present in the genome of all vertebrates and originated from infections of the germline of the host by exogenous retroviruses. ERVs... (Review)
Review
Endogenous retroviruses (ERVs) are present in the genome of all vertebrates and originated from infections of the germline of the host by exogenous retroviruses. ERVs have coevolved with their hosts for millions of years and are recognized to contribute to genome plasticity, protect the host against infection of related pathogenic and exogenous retroviruses, and play a vital role in development of the placenta. Consequently, some ERVs have been positively selected and maintained in the host genome throughout evolution. This review will focus on the critical role of ERVs in development of the mammalian placenta and specifically highlight the biological role of sheep JSRV-related endogenous betaretroviruses in conceptus (embryo and associated extraembryonic membranes) development.
Topics: Animals; Embryonic Development; Endogenous Retroviruses; Female; Humans; Jaagsiekte sheep retrovirus; Placenta; Placentation; Pregnancy; Sheep; Trophoblasts
PubMed: 20528833
DOI: 10.1111/j.1600-0897.2010.00860.x -
Journal of Medical Primatology Apr 2016Specific pathogen free (SPF) macaques provide valuable animal models for biomedical research. In 1989, the National Center for Research Resources [now Office of Research... (Review)
Review
Specific pathogen free (SPF) macaques provide valuable animal models for biomedical research. In 1989, the National Center for Research Resources [now Office of Research Infrastructure Programs (ORIP)] of the National Institutes of Health initiated experimental research contracts to establish and maintain SPF colonies. The derivation and maintenance of SPF macaque colonies is a complex undertaking requiring knowledge of the biology of the agents for exclusion and normal physiology and behavior of macaques, application of the latest diagnostic technology, facilitiy management, and animal husbandry. This review provides information on the biology of the four viral agents targeted for exclusion in ORIP SPF macaque colonies, describes current state-of-the-art viral diagnostic algorithms, presents data from proficiency testing of diagnostic assays between laboratories at institutions participating in the ORIP SPF program, and outlines management strategies for maintaining the integrity of SPF colonies using results of diagnostic testing as a guide to decision making.
Topics: Algorithms; Animals; Betaretrovirus; Deltaretrovirus Infections; Herpesviridae Infections; Herpesvirus 1, Cercopithecine; Macaca; Models, Animal; Monkey Diseases; Quality Control; Retroviridae Infections; Simian Acquired Immunodeficiency Syndrome; Simian Immunodeficiency Virus; Simian T-lymphotropic virus 1; Specific Pathogen-Free Organisms; Virus Diseases
PubMed: 26932456
DOI: 10.1111/jmp.12209 -
Viruses Aug 2022A Human Betaretrovirus (HBRV) has been identified in humans, dating as far back as about 4500 years ago, with a high probability of it being acquired by our species... (Review)
Review
A Human Betaretrovirus (HBRV) has been identified in humans, dating as far back as about 4500 years ago, with a high probability of it being acquired by our species around 10,000 years ago, following a species jump from mice to humans. HBRV is the human homolog of the MMTV (mouse mammary tumor virus), which is the etiological agent of murine mammary tumors. The hypothesis of a HMTV (human mammary tumor virus) was proposed about 50 years ago, and has acquired a solid scientific basis during the last 30 years, with the demonstration of a robust link with breast cancer and with PBC, primary biliary cholangitis. This article summarizes most of what is known about MMTV/HMTV/HBRV since the discovery of MMTV at the beginning of last century, to make evident both the quantity and the quality of the research supporting the existence of HBRV and its pathogenic role. Here, it is sufficient to mention that scientific evidence includes that viral sequences have been identified in breast-cancer samples in a worldwide distribution, that the complete proviral genome has been cloned from breast cancer and patients with PBC, and that saliva contains HBRV, as a possible route of inter-human infection. Controversies that have arisen concerning results obtained from human tissues, many of them outdated by new scientific evidence, are critically discussed and confuted.
Topics: Animals; Betaretrovirus; Breast Neoplasms; Female; High-Throughput Nucleotide Sequencing; Humans; Mammary Tumor Virus, Mouse; Mice; Proviruses
PubMed: 36016325
DOI: 10.3390/v14081704 -
Journal of Virology May 2002
Review
Topics: Animals; Avian Sarcoma Viruses; Calcium-Binding Proteins; DNA-Binding Proteins; Endosomal Sorting Complexes Required for Transport; Eukaryotic Cells; Gene Products, gag; HIV-1; Humans; Leukemia Virus, Murine; Ligases; Mammary Tumor Virus, Mouse; Mason-Pfizer monkey virus; Nedd4 Ubiquitin Protein Ligases; Protein Structure, Tertiary; Retroviridae; Transcription Factors; Ubiquitin-Protein Ligases; Virus Assembly
PubMed: 11967285
DOI: 10.1128/jvi.76.10.4679-4687.2002 -
Viruses Mar 2022For many decades, the betaretrovirus, mouse mammary tumour virus (MMTV), has been a causal suspect for human breast cancer. In recent years, substantial new evidence has... (Review)
Review
UNLABELLED
For many decades, the betaretrovirus, mouse mammary tumour virus (MMTV), has been a causal suspect for human breast cancer. In recent years, substantial new evidence has been developed. Based on this evidence, we hypothesise that MMTV has a causal role. We have used an extended version of the classic A. Bradford Hill causal criteria to assess the evidence. 1. Identification of MMTV in human breast cancers: The MMTV 9.9 kb genome in breast cancer cells has been identified. The MMTV genome in human breast cancer is up to 98% identical to MMTV in mice. 2.
EPIDEMIOLOGY
The prevalence of MMTV positive human breast cancer is about 35 to 40% of breast cancers in Western countries and 15 to 20% in China and Japan. 3. Strength of the association between MMTV and human breast cancer: Consistency-MMTV env gene sequences are consistently five-fold higher in human breast cancer as compared to benign and normal breast controls. 4. Temporality (timing) of the association: MMTV has been identified in benign and normal breast tissues up to 10 years before the development of MMTV positive breast cancer in the same patient. 5.
EXPOSURE
Exposure of humans to MMTV leads to development of MMTV positive human breast cancer. 6. Experimental evidence: MMTVs can infect human breast cells in culture; MMTV proteins are capable of malignantly transforming normal human breast epithelial cells; MMTV is a likely cause of biliary cirrhosis, which suggests a link between MMTV and the disease in humans. 7. Coherence-analogy: The life cycle and biology of MMTV in humans is almost the same as in experimental and feral mice. 8. MMTV Transmission: MMTV has been identified in human sputum and human milk. Cereals contaminated with mouse fecal material may transmit MMTV. These are potential means of transmission. 9. Biological plausibility: Retroviruses are the established cause of human cancers. Human T cell leukaemia virus type I (HTLV-1) causes adult T cell leukaemia, and human immunodeficiency virus infection (HIV) is associated with lymphoma and Kaposi sarcoma. 10. Oncogenic mechanisms: MMTV oncogenesis in humans probably differs from mice and may involve the enzyme APOBEC3B.
CONCLUSION
In our view, the evidence is compelling that MMTV has a probable causal role in a subset of approximately 40% of human breast cancers.
Topics: Animals; Betaretrovirus; Breast Neoplasms; Cytidine Deaminase; Female; Genes, env; Humans; Lymphoma; Mammary Tumor Virus, Mouse; Mice; Minor Histocompatibility Antigens
PubMed: 35458452
DOI: 10.3390/v14040721 -
Alimentary Pharmacology & Therapeutics Mar 2015
Topics: Betaretrovirus; Female; Hepatitis, Autoimmune; Hepatocytes; Humans; Liver Cirrhosis, Biliary; Male
PubMed: 25631651
DOI: 10.1111/apt.13068