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

Fourteen specific-pathogen-free cats were inoculated with a putative env gene recombinant feline retrovirus, PR8. An isolate of the Rickard strain of feline leukemia virus (FeLV-R), PR8, has the properties of both an exogenous (FeLV-R) and an endogenous (xenotropic) feline retrovirus (RD-114). Twelve of the PR8-inoculated cats developed viremia; 2 of the 12 cats developed eosinophilia, with 1 being diagnosed with eosinophilic leukemia and the other with extreme eosinophilic hyperplasia. Eosinophilic leukemia is rare in cats and has not previously been associated with retroviral infection. Changes in the viral envelope properties may have altered the pathogenicity of the exogenous virus to cause this rare form of leukemia.
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PMID:Retroviral-associated eosinophilic leukemia in the cat. 298 77

The nucleotide sequence of a full-length (8.8-kilobase) endogenous C-type human retroviral DNA (clone 4-1) is presented and compared with that of Moloney murine leukemia virus (MoMuLV) DNA. Colinearity of deduced amino acids of clone 4-1 with MoMuLV in the gag and pol regions was clearly evident, and overall amino acid homology in these regions was about 40%. Identification of the putative N terminus of gag and p30, the gag-pol junction, and the C terminus of pol could be established on the basis of sequence homology with MoMuLV. Unique characteristics of the endogenous human retroviral DNA included a tRNA Glu primer binding site separated from the 5' long terminal repeat by a pentanucleotide and a putative env sequence which does not appear to overlap the C terminus of pol and has virtually no homology with the env gene of known infectious retroviruses. Clone 4-1 represents a defective prototype of a human C-type retrovirus which integrated into the germ line some time in the distant past.
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PMID:Nucleotide sequence of a full-length human endogenous retroviral segment. 399 94

The DNA fragments of the 5' and 3' halves of the putative env gene predicted from the DNA sequence of human T-cell leukemia virus (HTLV) provirus were inserted into expression vectors pORF2 and pORF1, respectively, and two hybrid proteins composed of env polypeptides and beta-galactosidase were efficiently produced in Escherichia coli. The hybrid proteins containing the NH2-terminal (EH9) and COOH-terminal (EA1) halves were both immunologically reactive with sera from adult T-cell leukemia patients, demonstrating the utility of the hybrid proteins for diagnosis of HTLV infection. Rabbit antisera against these hybrid proteins detected the two glycoproteins gp62 and gp46, which were previously identified as HTLV env gene products. With these rabbit antisera, two properties of the env gene products were studied. (i) The antisera inhibited syncytia formation of cat S+L- cells induced by HTLV, suggesting that one or both of the env gene products of HTLV, gp62 and gp46, are involved in induction of cell fusion. (ii) The env product gp62 or gp46 or both products are exposed on the surface of HTLV-infected cells and might modulate the proliferation of HTLV-infected T cells in the host because the antisera against the hybrid proteins were cytotoxic on HTLV-producing cell lines. The latter conclusion also is supported by the fact that adult T-cell leukemia patients and healthy HTLV carriers have antibodies to the env gene products.
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PMID:Envelope proteins of human T-cell leukemia virus: expression in Escherichia coli and its application to studies of env gene functions. 609 Nov 39

Sera of individuals infected with adult T-cell leukaemia virus (ATLV) react predominantly with the polypeptides gp68, p24 and p19. These polypeptides were isolated from ATLV-infected MT-2 cells and virus. The radioiodinated polypeptides were used to quantify respective antibodies in individual ATLV carrier sera. Heteroantisera prepared in rabbits against isolated polypeptides facilitated studies on the biosynthesis of the core and envelope polypeptides of ATLV. Pulse-chase experiments revealed a polypeptide of mol. wt. 48 000 (48K) as the precursor to the core polypeptides p24 and p19. A 28K polypeptide related to p19 appeared to be an early side-product of the gag gene or a translate of a defective viral message. Antiserum to the putative env gene product gp68 recognized gp68, gp66 and small amounts of gp62. In tunicamycin-treated cells gp68, gp66 and gp62 were no longer synthesized, but a 54K polypeptide reacted with antiserum to gp68. Polypeptide p54 is structurally related to gp68 and therefore apparently represents the unglycosylated form of gp68. Moreover, the apparent mol. wt. of p54 and p48 agree with those predicted for respective env and gag precursors from the nucleotide sequence of an ATLV provirus.
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PMID:Precursor polypeptides of adult T-cell leukaemia virus: detection with antisera against isolated polypeptides gp68, p24 and p19. 609 96

The adult T-cell leukemia (ATL)-associated antigen complex (ATLA) is recognized by serum antibodies of carriers of ATL virus (ATLV). ATLA consists mainly of ATLV polypeptides and their precursors. The sera from 22 ATL patients, 21 healthy carriers and 9 healthy individuals were examined quantitatively by immunofluorescence assay (IF) for ATLA and by a newly developed radioimmunoprecipitation test with purified 125I-gp68, the putative env gene product of ATLV. More qualitative results were obtained by analysis on polyacrylamide gel (PAGE) of immunoprecipitates from lysates of 35S-cysteine-labelled cells producing ATLV, pelleted ATLV and cell-free culture supernatant. The two quantitative assays gave negative results with sera from all normal subjects and a few patients, but detected ATLA antibodies in all the healthy ATLV carriers. An important finding was that sera of patients that gave negative results in one assay gave positive results in the other, and vice versa. In contrast, all sera from ATL patients and healthy carriers, but not normal donors, precipitated ATLV-specific glycopolypeptides, gp68 and gp46 from 35S-labelled materials. But core polypeptides p28, p24, p19 and p15 were precipitated only by sera with IF titers of over 80. Thus, anti-ATLA antibodies in seropositive sera are predominantly directed against glycopolypeptides of ATLV, and the antibody reactivity to ATLA antigens does not differentiate between ATL patients at various stages of the disease and healthy ATLV carriers.
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PMID:Adult T-cell leukemia (ATL) virus-specific antibodies in ATL patients and healthy virus carriers. 660 32

A mutant of Moloney murine leukemia virus (M-MuLV), pMOV-psi-, was constructed by deletion of about 350 nucleotides from an infectious proviral DNA clone between the putative env mRNA 5' splice site and the AUG that initiates the coding sequence for Pr65gag. Although the parent wild-type proviral clone, pMOV-psi+, quickly causes a high level of reverse-transcriptase-containing virus particles to be released from transfected NIH/3T3 cells, transfection of pMOV-psi- into these cells initially results in very little release. By 9 to 10 days after transfection, however, pMOV-psi- -transfected cells produce infectious virus. Thus pMOV-psi- has a defect that can be repaired in transfected NIH/3T3 cells, presumably by recombination with a sequence normally present in the cells. Cell lines with pMOV-psi- stably integrated into chromosomal DNA produce reverse-transcriptase-containing particles that lack detectable M-MuLV RNA but the cells efficiently complement replication-defective, packagable retroviruses. Thus pMOV-psi- has a defect in the packaging of genomic RNA into virions but can provide in trans the products necessary for virion production. The deletion in pMOV-psi- appears to define a site required in cis for packaging of MuLV RNA into virions. Cell lines carrying pMOV-psi- can be used to produce helper-free stocks of natural or synthetic defective retroviruses.
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PMID:Construction of a retrovirus packaging mutant and its use to produce helper-free defective retrovirus. 667 8