Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

For examination of the influence of antibody on the pathogenesis of feline leukemia virus (FeLV) infection, 12 weanling specific-pathogen-free cats were inoculated with isolates of FeLV and were treated beginning at 7, 19, 21, 24, 34, or 49 days post inoculation (DPI) with feline anti-FeLV hyperimmune serum (10 infusions, 37 mg globulin/kg each at 48-hr intervals). Anti-FeLV serum infusion initiated at 7 DPI prevented the onset of hematopoietic cell infection and viremia. Antibody treatment initiated at 19 or 24 DPI abrogated recently established FeLV viremia and extinguished p27 expression in bone marrow and blood cells. Viremia established for longer periods was refractory to antibody infusion despite establishment of enzyme-linked immunosorbent assay antibody titers of 1:80 to 1:320 in the treated cats. Latent FeLV infection was a sequel to antibody-induced curtailment of viral replication in bone marrow cells and was able to reactivate spontaneously in vivo as well as in vitro.
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PMID:Influence of antibody infusion on pathogenesis of experimental feline leukemia virus infection. 298 57

Polypeptides specific for feline leukemia virus (FeLV) have been identified in the media of cells that produce FeLV as well as in nonproducer cells transformed by feline sarcoma viruses (FeSV). Cat fibroblasts that were persistently infected with FELV release the major virus envelope glycoprotein, whereas cultured cat lymphoma cells shed both glycopeptides related to the virus core gene (gag) and glycopeptides related to the virus envelope gene (env). Mink cells and cat cells transformed by FeSV secrete polypeptides of a wide range of sizes that cross-react with the major virus core protein p27. Differences in the classes of p27-related proteins produced may be related to the strain of virus and the cell type. Cat cells transformed by FeSV release a glycopeptide that appears to be processed differently from those identified in the media of FeSV-transformed mink cells. The possibility that such FeLV-related secretory proteins may interfere with the immune response of the host is discussed.
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PMID:Feline leukemia virus-and feline sarcoma virus-related polypeptides released by virus producer and nonproducer cells. 300 64

An effective subunit vaccine against feline leukemia virus infection and related diseases has been developed. The source of the vaccine immunogen is feline retrovirus persistently infected cells that continuously synthesize and shed virus polypeptides. Western blot analysis identifies FeLV-gp70, p27, p15, p12, and p10 in the subunit vaccine preparation. Cats immunized with the vaccine developed antibodies to a 70,000 MW protein of the vaccine that seems to be distinct from, but related to the FeLV-gp70 polypeptide.
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PMID:Feline leukemia vaccine: efficacy, contents and probable mechanism. 300 10

Monoclonal antibodies to p27 gag and v-fes specific determinants on the gag-onc poly-protein encoded by Snyder-Theilen feline sarcoma virus (ST-FeSV) were prepared. In order to obtain hybridoma clones specific to the antigenic determinants encoded by the FeSV genome, Lou rats were immunized with ST-FeSV-transformed, virus-nonproducing syngeneic cells, and boosted with either the same cells or affinity-purified feline leukemia virus (FeLV) p27. Three distinct clones reactive to both FeLV p27 and p85gag-fes, and one clone specific for a p85fes determinant were established. The anti-p27 monoclonal antibodies also reacted with the polyproteins p95gag-fes and p83gag-fgr, from Gardner-Arnstein (GA) and Theilen-Pedersen (TP1) FeSV, respectively. The anti-p27 monoclonal antibodies reacted with MuLV p30 and RD114 p28 but not with RSV, MMTV, or BLV. These results indicated that the part of the p27 gag gene that is preserved in ST-, GA, and TP1-FeSV encodes interspecies-specific p27 determinants.
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PMID:Monoclonal antibodies to the v-fes product and to feline leukemia: virus P27 interspecies-specific determinants encoded by feline sarcoma viruses. 302 6

The human T-cell leukemia virus type-1 (HTLV-1) contains a unique pX region, which encodes the gene products p40 chi, p27 chi-III and p21 chi-III. p40 chi is required for transcriptional trans-activation, whereas p27 chi-III and p21 chi-III have no such function. Transfection of pX expression plasmids containing different combinations for the three gene products into cells integrated with HTLV-1 proviruses defective in pX expression revealed that both p40 chi and p27 chi-III are required for expression of the gag protein and accumulation of gag mRNA. These observations suggest that the pX product p40 chi activates transcription and p27 chi-III controls the level of gag mRNA by post-transcriptional modulation.
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PMID:The second pX product p27 chi-III of HTLV-1 is required for gag gene expression. 302 15

The question was investigated whether feline leukemia virus (FeLV) infection may be diagnosed by testing saliva in an enzyme-linked immunosorbent assay (ELISA). Saliva was collected with commercially available swabs, eluted from the swabs, and tested in the ELISA. A comparison of results with saliva and serum samples from 60 specific-pathogen-free cats, 9 experimentally infected cats, and 1,117 field cats led to the following conclusions. False-positive saliva results, if any occurred, were rare events. During experimental infections, antigen excretion in saliva was observed 1.5 weeks after the first appearance of FeLV antigen in serum. In one of four positive serum samples from sick animals brought to veterinarians, saliva samples tested negative. The use of saliva in an ELISA for the detection of FeLV p27 in individual sick cats is therefore less reliable than the use of serum. In seven cats with diseases typical of FeLV, including one with an intestinal form of lyphosarcoma, saliva tested positive and serum tested negative. Based on the saliva and serum results for cats living in 92 multicat households, it was concluded that saliva may be a useful secretion for FeLV screening.
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PMID:Detection of feline leukemia virus infection in saliva. 303 65

An enzyme-linked immunosorbent assay (ELISA) for detection of feline leukemia virus (FeLV) p27 in saliva was tested for its accuracy and sensitivity in diagnosing FeLV infections. Saliva and serum samples from 564 clinical cases were tested with a 99.2% specificity. The overall accuracy of the saliva ELISA reactive to the serum ELISA was 97.9%. Experimentally, the ELISA saliva was the least sensitive in diagnosing early FeLV infections. However, the overall accuracy, ease of use, and simplicity of the test support its use as a screening procedure in clinical practice.
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PMID:Saliva as a source of feline leukemia virus antigen for diagnosis of disease. 303 50

The effects of protein modification on the antigenic determinants of p30 and gp70 of type C retroviruses were investigated by using solid-phase competition radioimmunoassays. Proteins were modified by reduction with 2-mercaptoethanol and subsequent carboxymethylation of SH groups with iodoacetamide or by amidination of alpha and epsilon amino groups with methylacetimidate. The type-specific determinants of gp70 were found to be conformational in nature, as they were destroyed by these chemical modifications. Group- and interspecies-specific determinants of gp70 antigens, however, appear to be sequential and do not involve residues susceptible to these chemical reagents. Conformation-dependent type-specific determinants of p30 were affected only by methylacetimidate. Group- and interspecies-specific determinants of p30 are similar to those of gp70 in that they also appear to be sequential antigenic sites. Therefore, the broadly reactive group- and interspecies-specific determinants of gp70 and p30 can be followed into small peptides. Accordingly, a cyanogen bromide cleavage fragment derived from the carboxyl-terminal one-third of Rauscher leukemia virus p30 was found to carry group-specific determinants but no detectable interspecies-specific determinants. In contrast, a peptide obtained by limited trypsin cleavage of p30, which was derived from the NH(2)-terminal region of the protein, contained at least one of the interspecies determinants shared with feline leukemia virus p27.
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PMID:Effect of chemical modification and fragmentation on antigenic determinants of internal protein p30 and surface glycoprotein gp70 of type C retroviruses. 615 54

Three different monoclonal antibodies were developed against the major core protein (p27) of feline leukemia virus (FeLV). Each antibody was directed against a different epitope of the species-specific portion of FeLV-p27. The 3 antibodies reacted with 5 different isolates of FeLV but not with 7 other retroviruses (MuLV (Rauscher), MuLV (AKR), MPMV, MMTV, SMRV, BAEV, RD 114). These monoclonal antibodies could readily be adapted to an enzyme-linked immunosorbent assay (ELISA) for the specific measurement of FeLV-p27. When compared in an ELISA with conventional reagents, the battery of monoclonal antibodies proved to be as sensitive as conventional polyclonal antibodies.
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PMID:Monoclonal antibodies to three epitopic regions of feline leukemia virus p27 and their use in enzyme-linked immunosorbent assay of p27. 618 44

The structural proteins as well as some features of the RNA-dependent DNA polymerase of the hamster endogenous retrovirus (HaER) were examined. The polypeptide pattern of this virus is substantially different from that of other known retroviruses in containing major polypeptides with molecular weights of 68,000, 59,000, 27,000 and 24,000 daltons. Double antibody competitive radioimmunoassays showed that the HaER particles do not share any detectable antigenic relatedness with the murine viruses' p30, but manifest a considerable relatedness with the feline leukemia virus p27 and a slight cross-reactivity with the rat virus major protein. The RNA-dependent DNA polymerase of HaER virus has a molecular size of approximately 73,000 daltons and in contrast to other mammalian retroviruses shows no significant preference for Mn2+ over Mg2+. Apart from the lack of antigenic relatedness between the HaER virus proteins and the p30 protein of murine viruses, there is also no antigenic relatedness between HaER and murine viruses insofar as their DNA polymerase is concerned.
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PMID:Hamster endogenous retrovirus (HaER)--distinct properties of structural proteins and DNA polymerase. 619 53


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