Because many viruses integrate their own genomes into the genomes of their host cells in order to replicate, mutagenesis caused by viral infections is a fairly common occurrence. (wikipedia.org)
However, if the insertion occurs in an essential gene or a gene that is involved in cellular replication or programmed cell death, the insertion may compromise the viability of the cell or even cause the cell to replicate interminably - leading to the formation of a tumor, which may become cancerous. (wikipedia.org)
Insertional mutagenesis is possible whether the virus is of the self-inactivating types commonly used in gene therapy or competent to replicate. (wikipedia.org)
The mechanism by which latent viruses, such as genetically transmitted tumor viruses ( PROVIRUSES ) or PROPHAGES of lysogenic bacteria, are induced to replicate and then released as infectious viruses. (lookformedical.com)
Exogenous1
Replication-defective vectors of reticuloendotheliosis virus transduce exogenous genes into somatic stem cells of the unincubated chicken embryo. (org.ua)
Gene6
The virus inserts a gene (known as a viral oncogene) normally near the cellular myc (c-myc)gene. (wikipedia.org)
however when it is turned on it is able to push the cell into the G1 phase of the cell cycle and cause the cell to begin replication, causing unchecked cell proliferation while allowing the viral gene to be replicated. (wikipedia.org)
After many replications where the viral gene stays latent tumours begin to grow. (wikipedia.org)
Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses. (lookformedical.com)
Appropriate in vivo expression of a muscle-specific promoter by using avian retroviral vectors for gene transfer [corrected]. (org.ua)
[19] Benchaibi M, Mallet F, Thoraval P, Savatier P, Xiao JH, Verdier G, Samarut J, Nigon V. Avian retroviral vectors derived from avian defective leukemia virus: role of the translational context of the inserted gene on efficiency of the vectors. (org.ua)
Tumor1
The molecular biology of RNA tumor virus. (org.ua)
Latent1
The ability of a pathogenic virus to lie dormant within a cell (latent infection). (lookformedical.com)
Viral3
For those viruses such as gammaretroviruses that tend to integrate their DNA in genetically unfavorable locations, the severity of any ensuing mutation depends entirely on the location within the host's genome wherein the viral DNA is inserted. (wikipedia.org)
Human immunodeficiency virus (HIV) and other lentiviruses adapt to new hosts by evolving to evade host-specific innate immune proteins that differ in sequence and often viral recognition between host species. (biomedcentral.com)
In eukaryotes, subsequent activation and viral replication is thought to be caused by extracellular stimulation of cellular transcription factors. (lookformedical.com)
Genetic3
Deoxyribonucleic acid that makes up the genetic material of viruses. (lookformedical.com)
Expression of Rous sarcoma virus-derived retroviral vectors in the avian blastoderm: potential as stable genetic markers. (org.ua)
GENES1
The murine leukemia virus (MLV) has been a powerful model of pathogenesis for the discovery of genes involved in cancer. (biomedcentral.com)
Cell1
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. (lookformedical.com)
Disease3
Avian leukosis virus is an example of a virus that causes disease by insertional mutagenesis. (wikipedia.org)
Bovine Leukemia Virus (BLV) is the etiological agent of enzootic bovine leukosis, a disease characterized by the neoplastic proliferation of B cells in cattle. (biomedcentral.com)
Virus shedding is an important means of vertical transmission (INFECTIOUS DISEASE TRANSMISSION, VERTICAL). (lookformedical.com)
The type species of ORTHOPOXVIRUS, related to COWPOX VIRUS , but whose true origin is unknown. (lookformedical.com)
Retroviral2
Analysis of the sequence of an infectious clone of the complete proviral genome indicates that HPRS-103 is a multiple recombinant of at least five ALSV sequences and one EAV (endogenous avian retroviral) sequence. (nih.gov)
To monitor the recovery of HIV-1 from patient plasma, samples are spiked with an internal virion standard, consisting of the replication-competent avian sarcoma)-leukosis retroviral vector RCAS BP(A) (RCAS), derived from an unrelated retrovirus based on Rous sarcoma virus (RSV). (abt-888.net)
Sarcoma2
The avian leukosis and sarcoma virus (ALSV) group comprises eight subgroups based on envelope properties. (nih.gov)
Perry Hackett, Ron Swanstrom, and Richard Parker have used conventional $-1 mapping procedures to determine splice sites for Rous sarcoma virus (RSV). (nih.gov)
Retroviruses3
Ht DEPARTMENT OF BIOCHEMISTRY & BIOPHYSICS Wa ANNUAL REPORT My 1982 1983 UNIVERSITY OF CALIFORNIA SAN FRANCISCO HAROLD E. VARMUS Professor of Microbiology and Immunology In this laboratory, we use two intriguing and medically-- important classes of animal viruses~--the retroviruses and hepatitis B-type viruses-~-as points of departure for studying various aspects of the behaviour of eukaryotic cells at the molecular level. (nih.gov)
The need to understand these and other aspects of retroviruses has become more urgent with the dis- covery that AIDS is caused by a retrovirus, the hu- man immunodeficiency virus (HIV). (nih.gov)
The re- 262 markable specificity of virus-host interactions has been known for over twenty years from studies of the polymorphic envelope proteins of avian retroviruses, yet little biochemical information is available about the receptors or about the nature of their interactions with viral envelope glycoproteins. (nih.gov)
Subgroup2
HPRS-103, an exogenous retrovirus recently isolated from meat-type chicken lines, is similar to the viruses of these subgroups in group antigen but differs from them in envelope properties and has been assigned to a new subgroup, J. HPRS-103 has a wide host range in birds, and unlike other nontransforming ALSVs which cause late-onset B-cell lymphomas, HPRS-103 causes late-onset myelocytomas. (nih.gov)
we have recently cloned avian genes encoding receptors for a subgroup of Rous sar- coma virus (RSV) and shown that the receptors resemble the receptor for low-density lipoproteins (LDL). (nih.gov)
Viral replication3
A parallel relationship was found between the degree of the viral replication and that of clinical signs of the respiratory disease, body weight loss, and histopathological changes in the lung. (nih.gov)
Throughout contamination an extraordinarily large number of viral replication cycles occurs, and this high replicative capacity of HIV-1 prospects to both varied genetic pools and high viral loads (2, 8). (abt-888.net)
Viremia could arise either from activation of virus expression from latently infected cell reservoirs or from ongoing cycles of viral replication, for example, in a sanctuary site where there is usually suboptimal drug penetration (1, 6, 31). (abt-888.net)
Murine leuke3
Ribosome profiling of the retrovirus murine leukemia virus. (medscape.com)
He has used techniques for in vitro mutagenesis to produce murine leukemia virus (MLV) pol mutants that retain reverse transcriptase activity but have lesions in the endonuclease domain. (nih.gov)
Recently, the receptor for ecotropic murine leukemia virus (MLV) was shown to be a very different type of protein, an amino acid permease with fourteen transmembrane domains. (nih.gov)
Reservoirs1
Beyond the replication-competent HIV reservoir: transcription and translation-competent reservoirs. (medscape.com)
Insertional5
Such insertional mutations can occur naturally, mediated by viruses or transposons, or can be artificially created for research purposes in the lab. (wikipedia.org)
Not all integrating viruses cause insertional mutagenesis, however. (wikipedia.org)
Insertional mutagenesis is possible whether the virus is of the self-inactivating types commonly used in gene therapy or competent to replicate. (wikipedia.org)
Avian leukosis virus is an example of a virus that causes disease by insertional mutagenesis. (wikipedia.org)
the Wnt-1 gene, discovered as a target for insertional activation by the mouse mammary tumor virus, belongs to a large family of genes encoding secretory proteins involved in important developmental events in many organisms. (nih.gov)
Immunodeficiency virus3
Replacement of feline foamy virus bet by feline immunodeficiency virus vif yields replicative virus with novel vaccine candidate potential. (medscape.com)
More sensitive assays for individual immunodeficiency virus type 1 (HIV-1) RNA are had a need to detect, quantify, and characterize persistent viremia in sufferers who are receiving antiretroviral therapy and whose plasma HIV-1 RNA amounts are suppressed to significantly less than 50 to 75 copies/ml. repeatedly tests a low-copy-number panel that contains 200 to 0.781 copies of HIV-1 RNA per ml of plasma. (abt-888.net)
Untreated human immunodeficiency virus type 1 (HIV-1) contamination is characterized by an early acute phase with high levels of viremia that leads to a clinically asymptomatic phase of variable duration, followed by immunodeficiency (15, 23). (abt-888.net)
Mutants1
These mutants appear to affect the integrative mechanism since mutant virus particles can enter cells and make full-sized unintegrated DNA, both linear and circular forms, but no virus is produced by the infected cells. (nih.gov)
Hepatitis1
In attempts to identify cell-surface receptors for Wnt proteins, we have developed several bioassays for Wnt genes and learned to make cell-free Wnt protein in a complex with the surface antigen of hepatitis B virus. (nih.gov)
Interactions1
General, these total results indicate that P10 acts as a significant effector in virus interactions. (researchensemble.com)
Virology1
But I've always felt that one of the key things to sort of opening up tumor virology was the isolation of a virus that you could work with in the lab that produced changes in tissue culture. (nih.gov)
Occur1
However, reduction of the HIV-1 RNA load to 50 copies/ml does not assurance long-term success, and a rebound of drug resistance can occur (20, 26), implying that HIV-1 replication and evolution may be continuing while patients are receiving therapy. (abt-888.net)
Infection2
The first isolations had been made from cultivated tonsils and adenoids, and the work was just beginning to try to understand what a broad spectrum of viruses was involved and what they had to do with human disease, with respiratory disease in the military, and with Trachoma and with pink eye and all the things that are now known to be associated with Adenovirus infection. (nih.gov)
And when Sarah Stewart and Bernice Eddy isolated Polyoma virus, we got involved in seeing how it could be handled in the laboratory and began a whole series of experiments that had to do with studying the natural history of Polyoma virus infection in lab mice, and Bob Huebner's particular interest in mice in the wild. (nih.gov)
Mechanism2
The overall results suggest that some activating mechanism for the progeny virus of wild-type Sendai virus exists in the lung of mice and the principle (activator) responsible for this phenomenon has a character similar to trypsin. (nih.gov)
Although a great deal is known about the synthesis of unintegrated double stranded viral DNA by the virus-coded enzyme, reverse transcriptase, we know only the structure features of integrated (proviral) DNA and none of the functional properties of the integrative mechanism. (nih.gov)
Form2
In this case, the progeny virus was produced in the activated form and multiple-cycle replication occurred successively. (nih.gov)
PMID- 6299951 TI - Pneumotropism of Sendai virus in relation to protease-mediated activation in mouse lungs. (nih.gov)
AB - The pneumotropism of Sendai virus in mice was studied in relation to the activation and replication of the virus in the lung. (nih.gov)
Mice4
Virus was not detected in heart tissues of adolescent ts 1 survivors, but inoculation of these mice with CVB3(m) resulted in virus concentrations similar in titers to those found in CVB3(m)-inoculated normal adolescent mice. (nih.gov)
Inactive Sendai virus grown in LLC-MK(2) cells, which possessed an uncleaved precursor glycoprotein, F, and was noninfectious to tissue culture cells, neither grew nor caused pathological changes in the lung of mice. (nih.gov)
A protease mutant, TR-2, which was able to be activated only by chymotrypsin but not by trypsin, could also initiate replication in the bronchial epithelium, when activated by chymotrypsin before inoculation into mice. (nih.gov)
And then we progressed, or moved, from there to studying indigenous viruses of mice, because we were beginning to use mice a lot for experimental purposes, and it became very clear that there were a lot of viruses already in the mice that weren't recognized, hadn't been classified, or tests worked out for their characterization. (nih.gov)
Mouse mamma1
John Majors has determined the splice sites for the mouse mammary tumor virus (MMTV) by sequencing a fortuitously encountered provirus copied from env mRNA. (nih.gov)
Give1
Although we continue to perform some of these studies with avian and murine retro- viruses, we give increasing attention to HIV. (nih.gov)