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  • infection
  • The evolution of xenotropism and cross-species infection is discussed in the light of the dynamic relationship between exogenous and endogenous retroviruses. (royalsocietypublishing.org)
  • For small DNA tumour viruses, the full replication cycle occurs via non-integrated circular viral genomes, whereas viral integration into host DNA usually leads to abortive infection and sometimes to cell transformation. (royalsocietypublishing.org)
  • Among such retrotransposed sequences are those characterized by the presence of long terminal repeats (LTRs), including the endogenous retroviruses (ERVs), which are inherited genetic elements closely resembling the proviruses formed following exogenous retrovirus infection. (asmscience.org)
  • Identification of a cellular cofactor required for infection by feline leukemia virus. (springer.com)
  • Normal DBA/2 mouse cells synthesize a glycoprotein which interferes with MCF virus infection. (springer.com)
  • Retrovirus tropism can be restricted by cellular factors such as Fv1, Ref1, and Lv1 that inhibit infection by targeting the incoming viral capsid. (asm.org)
  • Here, we show that rodent cells exhibit differential sensitivity to infection by vesicular stomatitis virus G-pseudotyped lentiviruses and that differences between human immunodeficiency virus type 1 and simian immunodeficiency virus (SIVmac) infectivity are sometimes, but not always, governed by determinants in capsid-p2. (asm.org)
  • One such activity is exhibited by the product of a murine gene, Fv1 , which can confer substantial resistance to infection by murine leukemia virus (MLV) ( 15 , 24 , 28 , 30 ). (asm.org)
  • Fv1-mediated restriction of MLV infection can be overcome at high multiplicities of infection, and infection of restricting cells can give rise to multihit titration curves, implying that infection by one virus particle is facilitated by the presence of others ( 1 , 7 , 10 , 13 , 31 , 34 ). (asm.org)
  • Nonhuman primate cells are resistant to infection by HIV-1, and studies of viral DNA formation and those involving pseudotyped viruses indicate that the block is at an early postentry step ( 17 , 18 , 33 ). (asm.org)
  • Thus, the main hypothesis currently being tested in clinical trials is that CTL responses can be induced safely in humans and will impact upon viral load and disease progression as they have done in primate models of simian-human immunodeficiency virus (SHIV) infection. (centrallakesclinic.biz)
  • In macaque models, vaccination with DNA plasmids or recombinant viruses bearing SIV SHIV antigenic inserts leads to significant attenuation of viremia after subsequent infection with the highly pathogenic X4-tropic hybrid isolate SHIV89.6P. Although they do not afford sterilizing immunity under any regimen tested thus far, such vaccines enable long-term suppression of viremia and prevent disease progression. (centrallakesclinic.biz)
  • recombinant
  • 2011. Recombinant origin of the retrovirus XMRV. (asmscience.org)
  • By use of the same forced recombination system, we have now found recombinant proviruses of different structures, suggesting that PBS knockout vectors may be rescued through initial priming on endogenous virus RNA, read-through of the mutated PBS during minus-strand synthesis, and subsequent second-strand transfer mediated by the R-U5 complementarity of the plus strand and the extended minus-strand DNA acceptor template. (asm.org)
  • encodes
  • Thirteen years later, it was shown that the oncogene transduced by this virus encodes a serine/threonine protein kinase (AKT) (also known as PKB), which harbors an N-terminal regulatory domain (now known as the PH domain) and exhibits a high degree of homology with the kinases PKC and PKA ( 2 - 5 ). (sciencemag.org)
  • genome
  • Detection and cloning of human DNA sequences related to the mouse mammary tumor virus genome. (asmscience.org)
  • Retroviruses harbor a diploid single-stranded RNA genome which constitutes the source for generation of double-stranded DNA by reverse transcription. (asm.org)
  • Our current knowledge of TEs in laboratory mouse strains is limited primarily to those present in the C57BL/6J reference genome, with most mouse TEs being drawn from three distinct classes, namely short interspersed nuclear elements (SINEs), long interspersed nuclear elements (LINEs) and the endogenous retrovirus (ERV) superfamily. (biomedcentral.com)
  • Polypurine tract adjacent to the U3 region of the Rous sarcoma virus genome provides a cis-acting function. (asm.org)
  • An obvious hypothesis is that retroviruses have evolved to preferentially package two copies of genomic RNA, and that dimerization ensures the proper packaging specificity for such a genome. (biomedcentral.com)
  • Since then, RNA and protein sequences involved in genome dimerization have been identified for a number of retroviruses, and the dimeric nature of the retroviral genome is known to be important for various critical events in the viral life cycle. (biomedcentral.com)
  • The virus integrates into the cellular genome and inserts its DNA near or within genes, which leads to various outcomes: (i) The insertion site is too far away from a protooncogene and thus does not activate it. (biomedcentral.com)
  • sequences
  • Colicelli J, Goff SP (1987) Identification of endogenous retroviral sequences as potential donors for recombinational repair of mutant retroviruses: Positions of crossover points. (springer.com)
  • We have previously demonstrated recombinational rescue of primer binding site (PBS)-impaired Akv murine leukemia virus-based vectors involving initial priming on endogenous viral sequences and template switching during cDNA synthesis to obtain PBS complementarity in second-strand transfer of reverse transcription (Mikkelsen et al. (asm.org)
  • Endogenous viral RNAs found to be encapsidated in virus particles ( 13 , 32 , 43 , 49 ) may thus serve to provide the functional sequences required for repair of deleterious viral mutations. (asm.org)
  • restriction
  • In agreement with the essential role of the PBS in initiation and completion of reverse transcription ( 35 , 47 , 62 ), we previously observed a strong restriction in transduction of Akv murine leukemia virus (MLV) vectors with PBSs having only partial (PBS-XXX) or no [PBS-UMU and PBS-Met(i)int] homology with the 3′ end of any known murine tRNA molecule ( 32 ). (asm.org)
  • Mechanisms of late restriction induced by an endogenous retrovirus. (springer.com)
  • Because of this and the fact that precisely the same saturation phenomenon that was described in the context of murine Fv1-mediated restriction is also observed in human cells ( 36 ), it is probable that humans also express an inhibitor, termed Ref1, that exhibits restriction specificity similar to that of Fv1 b . (asm.org)
  • ERVs
  • Most ERVs are defective for production of infectious virus. (springer.com)
  • These ERVs affect retrovirus-induced disease in a number of ways, including manipulation of the immune response, inhibition or facilitation of entry or other steps of virus replication, or as participants in the generation of infectious pathogenic viruses. (springer.com)
  • However, multiple examples show that additional pathogenic retroviruses will continue to emerge using ERVs as a source of genetic diversity. (springer.com)
  • translocations
  • Since HRX ‐associated leukemias often express markers of both lymphoid and myeloid lineages, it is possible that HRX translocations may occur at the level of a multipotent hematopoietic progenitor or hematopoietic stem cell (HSC), leading to the disruption of normal genetic programs for terminal differentiation. (embopress.org)
  • lymphoid
  • In particular, leukemias with the t(11;19)(q23;p13.3) translocation express HRX-ENL fusion proteins and display features which suggest the malignant transformation of myeloid and/or lymphoid progenitor(s). (embopress.org)
  • viral
  • Integration of viral DNA into host DNA was first discerned for the prophage of the temperate bacteriophage lambda by Andre Lwoff in 1950 and for the simian DNA virus SV40 in cultured mammalian cells in 1968 [ 8 ]. (royalsocietypublishing.org)
  • This indicates that some human cells express a protein on their surface that acts as a receptor for MCF viruses and allows MCF viral entry. (umassmed.edu)
  • During virus assembly, all retroviruses specifically encapsidate two copies of full-length viral genomic RNA in the form of a non-covalently linked RNA dimer. (biomedcentral.com)
  • XMRV
  • We introduced several mutations disrupting two putative but noncanonical glyco-gag proteins in the leader sequence region in XMRV and found that those mutations did not affect virus release nor susceptibility to the antiviral activity of hA3G (human APOBEC3G). (biomedcentral.com)
  • electron
  • Electron microscope studies of ultrathin sections from visna virus infected cells demonstrated spherical particles, 70-100 nm in diameter, which were formed by budding from the cell membrane. (rapeutation.com)
  • inhibition
  • With the discovery that the causative agent of AIDS was also a retrovirus, inhibition of RNA dimerization was proposed as a possible therapy for HIV, and HIV-1 RNA dimerization became an intensely studied topic. (biomedcentral.com)
  • Rous
  • I first came across an endogenous factor which functionally complemented env -defective Rous sarcoma virus (RSV) during my doctoral studies in 1966. (royalsocietypublishing.org)
  • That was the year that Peyton Rous was awarded the Nobel Prize for Medicine or Physiology for the isolation of his eponymous virus published in 1911, representing a record 55 year incubation period between reporting a discovery and the award [ 6 ]. (royalsocietypublishing.org)
  • AIDS
  • Alizon M, Wain-Hobson S, Montagnier L, Sonigo P (1986) Genetic variability of the AIDS virus: nucleotide sequence analysis of two isolates from African patients. (springer.com)
  • Coffin JM (1986) Genetic variation in AIDS viruses. (springer.com)
  • This includes what must be the most significant transmissible disease of humans in recent times, acquired immunodeficiency syndrome (AIDS), which is caused by the retroviruses Human Immunodeficiency Virus Types 1 and 2 (HIV-1, HIV-2). (biomedcentral.com)
  • AIDS Res Hum Retroviruses. (ucsf.edu)
  • However, as with many topics in retrovirology, interest in this area was heightened with the realization that the causative agent of AIDS was a retrovirus. (biomedcentral.com)
  • In the early 1980s, the causative agent of AIDS was found to be a non-oncogenic retrovirus and was classified as a lentivirus. (rapeutation.com)
  • vectors
  • To address this issue, primary and immortalized human cells were tested for their ability to be infected by MCF packaged defective vectors as well as replication competent MCF virus. (umassmed.edu)
  • In addition, it is clear that the probability of such events can be greatly reduced by relatively simple vector modifications, such as the use of self-inactivating vectors and vectors derived from non-oncogenic retroviruses. (biomedcentral.com)
  • tropism
  • Human immunodeficiency virus type 1 (HIV-1) exhibits a highly restricted host cell tropism and is only capable of efficient replication in primary or immortalized human T cells and macrophages. (asm.org)
  • closely
  • Virtually all mammals-as well as some birds, reptiles, and fish-have yielded infectious retroviruses when examined sufficiently closely. (springer.com)
  • cell
  • The recognition of the importance of Rous's discovery after such a long delay was largely owing to the cell transformation assay in monolayer culture of chick embryo fibroblasts reported by Temin & Rubin [ 7 ] in 1958 which enabled quantitative experimental studies of virus replication and cell transformation. (royalsocietypublishing.org)
  • E710.2.3 is a murine thymic lymphoma cell line with an immature phenotype (CD4 − CD8 − ) that proliferates in response to thymocytes or PMA when cultured at low density and proliferates spontaneously when grown at high density. (jimmunol.org)
  • The DMF10 62.3 mAb stained a number of immortalized murine and human cell lines and, where tested, blocked their proliferation and caused death to varying extents by apoptosis. (jimmunol.org)
  • E710.2.3 is a cloned murine CD4 − CD8 − thymic T lymphoma cell line. (jimmunol.org)
  • However, it has also illustrated the potential dangers involved, with 2 out of 10 patients developing T cell leukemia as a consequence of the treatment. (biomedcentral.com)
  • Expression of mouse mammary tumor virus superantigen mRNA in the thymus correlates with kinetics of self-reactive T-cell loss. (springer.com)
  • Effect of tunicamycin on the synthesis of herpes simplex virus type 1 glycoproteins and their expression on the cell surface. (asm.org)
  • Additional and as-yet-poorly characterized blocks in late steps of the virus life cycle ultimately lead to a profound defect (10 3 - to 10 4 -fold) in the yield of infectious virions per infected cell ( 4 , 26 ). (asm.org)
  • The CD8+ cell non-cytotoxic antiviral response affects RNA polymerase II-mediated human immunodeficiency virus transcription in infected CD4+ cells. (ucsf.edu)
  • molecular
  • Bova CA, Manfredi JP, Swanstrom R (1986) Genes of avian retroviruses: Nucleotide sequence and molecular recombinants define host range determinants. (springer.com)
  • Molecular cloning of cDNA for murine interleukin-3. (springer.com)
  • Biologic, serologic, and molecular characterization of several HIV-1 and HIV-2 strains has revealed their extensive heterogeneity and how viruses can evolve differently in the same individual in the immune system, bowel, and the brain. (ucsf.edu)
  • human
  • Indeed, germ-line integration has not yet been described for DNA tumour viruses, although we now know that it occasionally occurs with human herpesvirus 6 [ 9 , 10 ]. (royalsocietypublishing.org)
  • 2008. Human RNA "rumor" viruses: the search for novel human retroviruses in chronic disease. (asmscience.org)
  • In addition, I show that some human cells fully support MCF virus replication while others either partially or fully restrict MCF virus replication. (umassmed.edu)
  • Rate of recombinational deletion among human endogenous retroviruses. (springer.com)
  • Human T-Lymphotropic Virus. (ucsf.edu)
  • This report updates and consolidates all previous U.S. Public Health Service recommendations for the management of health-care personnel (HCP) who have occupational exposure to blood and other body fluids that might contain hepatitis B virus (HBV), hepatitis C virus (HCV), or human immunodeficiency virus (HIV). (cdc.gov)
  • Avoiding occupational blood exposures is the primary way to prevent transmission of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) in health-care settings ( 1 ). (cdc.gov)
  • Genetic
  • Genetic evidence for vaccinia virus-encoded DNA polymerase: isolation of phosphonoacetate-resistant enzyme from the cytoplasm of cells infected with mutant virus. (asm.org)