Gammaretrovirus: A genus of RETROVIRIDAE comprising endogenous sequences in mammals, related RETICULOENDOTHELIOSIS VIRUSES, AVIAN, and a reptilian virus. Many species contain oncogenes and cause leukemias and sarcomas.Xenotropic murine leukemia virus-related virus: An endogenous GAMMARETROVIRUS from the germ line of mice but isolated from humans. It has close similarity to xenotropic MURINE LEUKEMIA VIRUS.Retroviridae Infections: Virus diseases caused by the RETROVIRIDAE.Phascolarctidae: A family of marsupials in the order Diprotodontia, native to Australia and possessing vestigial tails. There is a single living genus and species: Phascolarctos cinereus, the koala.Whale, Killer: The species Orcinus orca, in the family Delphinidae, characterized by its black and white coloration, and huge triangular dorsal fin. It is the largest member of the DOLPHINS and derives its name from the fact that it is a fearsome predator.Leukemia Virus, Murine: Species of GAMMARETROVIRUS, containing many well-defined strains, producing leukemia in mice. Disease is commonly induced by injecting filtrates of propagable tumors into newborn mice.Endogenous Retroviruses: Retroviruses that have integrated into the germline (PROVIRUSES) that have lost infectious capability but retained the capability to transpose.DNA Contamination: The presence of DNA from a source foreign to the sample being analysed.Tumor Virus Infections: Infections produced by oncogenic viruses. The infections caused by DNA viruses are less numerous but more diverse than those caused by the RNA oncogenic viruses.Leukemia Virus, Feline: A species of GAMMARETROVIRUS causing leukemia, lymphosarcoma, immune deficiency, or other degenerative diseases in cats. Several cellular oncogenes confer on FeLV the ability to induce sarcomas (see also SARCOMA VIRUSES, FELINE).Fatigue Syndrome, Chronic: A syndrome characterized by persistent or recurrent fatigue, diffuse musculoskeletal pain, sleep disturbances, and subjective cognitive impairment of 6 months duration or longer. Symptoms are not caused by ongoing exertion; are not relieved by rest; and result in a substantial reduction of previous levels of occupational, educational, social, or personal activities. Minor alterations of immune, neuroendocrine, and autonomic function may be associated with this syndrome. There is also considerable overlap between this condition and FIBROMYALGIA. (From Semin Neurol 1998;18(2):237-42; Ann Intern Med 1994 Dec 15;121(12): 953-9)Terminal Repeat Sequences: Nucleotide sequences repeated on both the 5' and 3' ends of a sequence under consideration. For example, the hallmarks of a transposon are that it is flanked by inverted repeats on each end and the inverted repeats are flanked by direct repeats. The Delta element of Ty retrotransposons and LTRs (long terminal repeats) are examples of this concept.Receptors, Virus: Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.Gene Products, env: Retroviral proteins, often glycosylated, coded by the envelope (env) gene. They are usually synthesized as protein precursors (POLYPROTEINS) and later cleaved into the final viral envelope glycoproteins by a viral protease.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Prostatic Neoplasms: Tumors or cancer of the PROSTATE.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Xenotropic murine leukemia virus-related virus: Xenotropic murine leukemia virus-related virus (XMRV) is "a laboratory-derived mouse virus that was generated through recombination between two endogenous murine retroviruses during propagation of a prostate cancer xenograft in the mid-1990’s." via EBSCO login The chimeric virus was first described in 2006 as an apparently novel retrovirus and potential human pathogen.Koala retrovirus: Koala retrovirus (KoRV) is a retrovirus that is present in many populations of koalas. It has been implicated as the agent of Koala Immune Deficiency Syndrome (KIDS), an AIDS-like immunodeficiency that leaves infected koalas more susceptible to infectious disease and cancers.Chimo (killer whale): Chimo (also known as T4), was a young female orca exhibited in Sealand of the Pacific in South Oak Bay at The Oak Bay Marina, near the city of Victoria, in British Columbia, Canada from 1970 to 1972. Chimo was notable for being the only partially albino orca ever exhibited in captivity.Endogenous retrovirusNucleic acid quantitation: In molecular biology, quantitation of nucleic acids is commonly performed to determine the average concentrations of DNA or RNA present in a mixture, as well as their purity. Reactions that use nucleic acids often require particular amounts and purity for optimum performance.Reuben Rickard: Reuben Rickard (August 20, 1841 – February 28, 1896) was a mining engineer who served as President of the Town Board of Trustees in Berkeley, California from 1891 to 1893, and again for about one month during 1895.Derek Enlander: Derek Enlander is a clinical instructor of medicine on the faculty of the Icahn School of Medicine at Mount Sinai in New York. He was born in Belfast, Northern Ireland and attended medical school in Dublin.Coles PhillipsBranching order of bacterial phyla (Gupta, 2001): There are several models of the Branching order of bacterial phyla, one of these was proposed in 2001 by Gupta based on conserved indels or protein, termed "protein signatures", an alternative approach to molecular phylogeny. Some problematic exceptions and conflicts are present to these conserved indels, however, they are in agreement with several groupings of classes and phyla.CabazitaxelProtein primary structure: The primary structure of a peptide or protein is the linear sequence of its amino acid structural units, and partly comprises its overall biomolecular structure. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end.
(1/371) Vesicular stomatitis virus G pseudotyped retrovector mediates effective in vivo suicide gene delivery in experimental brain cancer.
Direct in vivo tumor-targeting with "suicide" viral vectors is limited by either inefficient gene transfer (i.e., retroviral vectors) or indiscriminate transfer of a conditionally toxic gene to surrounding nonmalignant tissue (i.e., adenoviral vectors). Retrovectors pseudotyped with the vesicular stomatitis virus G protein (VSVG) may serve as a remedy to this conundrum. These retroviral particles differ from standard murine retroviruses by their very broad tropism and the capacity to be concentrated by ultracentrifugation without loss of activity. We propose that a VSVG-typed retrovector can be used for efficient and tumor-specific herpes simplex virus thymidine kinase (TK) gene delivery in vivo. To test this hypothesis, we developed a bicistronic retroviral vector that expresses TK and green fluorescence protein (pTKiGFP). The 293GPG packaging cell line was used to generate vTKiGFP retroparticles. In cytotoxicity assays, vTKiGFP-transduced human glioma cell lines were sensitized to the cytotoxic effects of gangciclovir (GCV) 10,000-fold. Subsequently, virus was concentrated by ultracentrifugation to a titer of 2.3 x 10(10) cfu/ml. We tested the antitumor activity of vTKiGFP retroparticles in a rat C6 glioma model of brain cancer. Concentrated retrovector stock (9 microl volume) was injected stereotactically in preestablished intracerebral tumor. Subsequently, rats were treated with GCV for 10 days. Control rats (no GCV) had a mean survival of 38 days (range, 20-52 days). Sections performed on postmortem brain tissue revealed large tumors with evidence of high efficiency retrovector transfer and expression (as assessed by GFP fluorescence). Fluorescence was restricted to malignant tissue. In the experimental group (GCV treated), 8 of 12 remain alive and well >120 days after glioma implantation. In conclusion, vTKiGFP is very efficient at transducing human glioma cell lines in vitro and leads to significant GCV sensitization. Recombinant retroviral particles can be concentrated to titers that allow in vivo intratumoral delivery of large viral doses. The therapeutic efficiency of this reagent has been demonstrated in a preclinical model of brain cancer. (+info)
(2/371) Search for cross-species transmission of porcine endogenous retrovirus in patients treated with living pig tissue. The XEN 111 Study Group.
Pig organs may offer a solution to the shortage of human donor organs for transplantation, but concerns remain about possible cross-species transmission of porcine endogenous retrovirus (PERV). Samples were collected from 160 patients who had been treated with various living pig tissues up to 12 years earlier. Reverse transcription-polymerase chain reaction (RT-PCR) and protein immunoblot analyses were performed on serum from all 160 patients. No viremia was detected in any patient. Peripheral blood mononuclear cells from 159 of the patients were analyzed by PCR using PERV-specific primers. No PERV infection was detected in any of the patients from whom sufficient DNA was extracted to allow complete PCR analysis (97 percent of the patients). Persistent microchimerism (presence of donor cells in the recipient) was observed in 23 patients for up to 8.5 years. (+info)
(3/371) Sequence and insertion sites of murine melanoma-associated retrovirus.
We previously showed that B16 melanoma cells produce ecotropic melanoma-associated retrovirus (MelARV) which encodes a melanoma-associated antigen recognized by MM2-9B6 monoclonal antibody. The biological significance of MelARV in melanoma formation remains unknown. We found that infection of normal melanocytes with MelARV resulted in malignant transformation. It is likely that MelARV emerged from the defective Emv-2 provirus, a single copy of ecotropic provirus existing in the genome of C57BL/6 mice. In the present study, we cloned and sequenced the full-length MelARV genome and its insertion sites and we completed sequencing of the Emv-2 provirus. Our data show that MelARV has a typical full-length retroviral genome with high homology (98.54%) to Emv-2, indicating a close relationship between both viruses. MelARV probably emerged as a result of recombination between Emv-2 and an endogenous nonecotropic provirus. Some observed differences in the gag and pol regions of MelARV might account for the restoration of productivity and infectivity of a novel retrovirus that somatically emerged during melanoma formation. MelARV does not contain any oncogene and therefore might induce transformation by insertional mutagenesis. We sequenced two insertion sites of MelARV. The first insertion site represents the 3' coding region of the c-maf proto-oncogene at 67.0 centimorgans (cM) on chromosome 8. The c-maf proto-oncogene encodes a basic leucine zipper protein homologous to c-fos and c-jun. Insertion of MelARV in BL6 melanoma cells resulted in the up-regulation of c-maf. It is noteworthy that the Emv-2 provirus is also inserted into a noncoding region at 61.0 cM on the same chromosome 8. The second insertion site is the 3' noncoding region of the DNA polymerase gamma (PolG) gene on chromosome 7. The expression of PolG was not affected by the MelARV insertion. Further investigation of the biological significance of MelARV in melanoma formation is being undertaken. (+info)
(4/371) Differential glycosylation of the Cas-Br-E env protein is associated with retrovirus-induced spongiform neurodegeneration.
The wild mouse ecotropic retrovirus, Cas-Br-E, induces progressive, noninflammatory spongiform neurodegenerative disease in susceptible mice. Functional genetic analysis of the Cas-Br-E genome indicates that neurovirulence maps to the env gene, which encodes the surface glycoprotein responsible for binding and fusion of virus to host cells. To understand how the envelope protein might be involved in the induction of disease, we examined the regional and temporal expression of Cas-Br-E Env protein in the central nervous systems (CNS) of mice infected with the highly neurovirulent chimeric virus FrCas(E). We observed that multiple isoforms of Cas-Br-E Env were expressed in the CNS, with different brain regions exhibiting unique patterns of processed Env glycoprotein. Specifically, the expression of gp70 correlated with regions showing microglial infection and spongiform neurodegeneration. In contrast, regions high in neuronal infection and without neurodegenerative changes (the cerebellum and olfactory bulb) were characterized by a gp65 Env protein isoform. Sedimentation analysis of brain region extracts indicated that gp65 rather than gp70 was incorporated into virions. Biochemical analysis of the Cas-Br-E Env isoforms indicated that they result from differential processing of N-linked sugars. Taken together, these results indicate that differential posttranslational modification of the Cas-Br-E Env is associated with a failure to incorporate certain Env isoforms into virions in vivo, suggesting that defective viral assembly may be associated with the induction of spongiform neurodegeneration. (+info)
(5/371) TCR v(beta) repertoire restriction and lack of CDR3 conservation implicate TCR-superantigen interactions in promoting the clonal evolution of murine thymic lymphomas.
Thymic lymphoma development is a multistage process in which genetic and epigenetic events cooperate in the emergence of a malignant clone. The notion that signaling via TCR-ligand interactions plays a role in promoting the expansion of developing neoplastic clones is a matter of debate. To investigate this issue, we determined the TCR V(beta) repertoire of thymic lymphomas induced in AKR/J mice by either endogenous retroviruses or the carcinogen, N-methyl-N-nitrosourea (MNU). Both spontaneous and MNU-induced lymphomas displayed restricted V(beta) repertoires. However, whereas V(beta)6, V(beta)8 and V(beta)9 were expressed by a greater than expected frequency of MNU-induced lymphomas, V(beta)8, V(beta)7, V(beta)13 and V(beta)14 were over-represented on spontaneous lymphomas. The dissimilar TCR V(beta) profiles indicate that different endogenous ligands promote neoplastic clonal expansion in untreated and MNU-treated mice. Although the nature of these ligands is not clear, the lack of conservation in TCR beta chain CDR3 regions among lymphomas that express the same V(beta) segment suggests that endogenous superantigens (SAG), as opposed to conventional peptide ligands, are likely to be involved in the selection process. The biased representation of lymphomas expressing V(beta)6-, V(beta)7- and V(beta)9-containing TCRs that recognize endogenous SAG is consistent with this hypothesis. The finding that Bcl-2 is expressed at high levels in spontaneous and MNU-induced lymphomas suggests that preneoplastic thymocytes may be resistant to SAG-induced clonal deletion. A working model is presented in which preneoplastic clones expressing TCRs that recognize endogenous SAG are selectively expanded as a consequence of sustained TCR-mediated signaling. (+info)
(6/371) Canine large granular lymphocyte leukemia and its derived cell line produce infectious retroviral particles.
We describe a case of large granular lymphocyte (LGL) leukemia in a dog that we followed over a period of 2 years. Analysis of a hematological profile revealed lymphocytosis (19,500 lymphocytes per microliter; reference values, 1,000-4,800 lymphocytes per microliter), with a majority of LGL on the blood smear. LGL is defined as a lymphoid subset comprising 10% of peripheral blood mononuclear cells and corresponding to either CD3- CD8- NK cells or CD3+ CD8+ T cells. The cells are characterized by abundant basophilic cytoplasm containing distinct granules of variable size and number. The characteristic phenotype of our leukemic LGL is of a cytotoxic T cell, CD3+ and CD8+. A new cell line, DLC 02, was established from the peripheral lymphocytes of the leukemic dog. Particles with type C retroviral morphology were found in ultrathin sections of DLC 02 cell pellets. These particles were found to have a sucrose gradient density of 1.17 g/liter and a reverse transcriptase activity with an Mn2+ preference, suggesting that they correspond to a mammalian type C oncovirus. (+info)
(7/371) Contrastive prevalence of feline retrovirus infections between northern and southern Vietnam.
The prevalence of infections with three feline retroviruses; feline leukemia virus (FeLV), feline immunodeficiency virus (FIV) and feline foamy virus (FeFV), was examined in domestic cats (Felis catus) and leopard cats (Felis bengalensis) in southern Vietnam in 1998. We then compared this data with our previous study in northern Vietnam in 1997. None of the cats had FeLV antigens in both the northern and southern areas. In contrast, there is a great distinction in the seropositivity of FIV. Twenty-two percent of domestic cats had FIV antibodies whereas no FIV positive cats were detected in northern area. FIV may have entered southern Vietnam recently and spread rapidly. FeFV infections were found in both areas, suggesting that FeFV might be present in the cat populations in Vietnam from the earliest time. (+info)
(8/371) Discovery of a novel murine type C retrovirus by data mining.
Analysis of genomic and expression data allows both identification and characterization of novel retroviruses. We describe a recombinant type C murine retrovirus, similar to the Mus dunni endogenous retrovirus, with VL30-like long terminal repeats and murine leukemia virus-like coding sequences. This virus is present in multiple copies in the mouse genome and expressed in a range of mouse tissues. (+info)