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)

Three distinct monoclonal antibodies (MAbs) specific for human T-cell leukemia virus type-I (HTLV-I) core proteins with molecular weights of 24 kDa (p24), p19 or p15 were produced, characterized and compared. These antibodies were named NOR-1 (anti-p24, IgG2a), GIN-7 (anti-p19, IgG2b) and FR-45 (anti-p15, IgG2a). Immunofluorescence assay showed that they reacted specifically with methanol-fixed cells of virus-bearing cell lines, and that only GIN-7 bound, albeit weakly, to the surface of a small percentage of viable cells. Like natural antibodies to HTLV-I in human serum, GIN-7 stained the fixed cells brightly and diffusely, and gave more intense fluorescence than NOR-1 and FR-45, which stained restricted areas of the cells. NOR-1, GIN-7 and FR-45 specifically precipitated core proteins p24, p19 and p15, respectively, from a lysate of HTLV-IMT-2 labelled with 35S-cysteine. NOR-1 precipitated p53, p36, and p24, GIN-7 precipitated p53, p32, p28 and p19, and FR-45 precipitated p53, p36, and p15 from a lysate of 35S-cysteine-labelled MT-2 cells. GIN-7 also precipitated p32, p28 and p19 from a lysate of MT-2 cells, labelled by surface iodination, but NOR-1 and FR-45 did not detect any proteins in this lysate. GIN-7 also detected p28 in 3H-glucosamine-labelled MT-2 cells. Antibody binding competition assay showed that the sera of ATL patients significantly interfered with the binding of NOR-1 and GIN-7 but not with that of FR-45, to antigens of disrupted virus of MT-2 cells. This complete set of MAbs against the HTLV-I gag gene products is useful for biological and functional studies of the HTLV-I core proteins.
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PMID:Antigens related to three core proteins of HTLV-I (p24, p19 and p15) and their intracellular localizations, as defined by monoclonal antibodies. 300 Sep 53

Peripheral blood lymphocytes from 2 normal individuals seronegative for human T-cell leukemia virus type I (HTLV-I) were co-cultured with HTLV-I-producing MT-2 cells that had been heated at 56 degrees for 30 min or exposed to 10,000 rad of X-irradiation. HTLV-I-induced lymphocyte transformation was consistently achieved by co-culture with irradiated MT-2 cells but not by co-culture with heated MT-2 cells. The heat treatment was found to be lethal to both MT-2 cells and the virus. These findings are discussed in terms of their potential clinical application for preventing the transmission of HTLV-I.
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PMID:Inactivation of lymphocyte-transforming activity of human T-cell leukemia virus type I by heat. 300 13

Co-cultivation of spleen cells of Syrian golden hamsters with lethally irradiated MT-2 cells harboring human T-cell leukemia virus type I (HTLV-I) resulted in the establishment of lymphoid cell lines, HCT-1 and HCT-2, which exhibited the normal karyotype of golden hamsters. Cells of both the HCT-1 and HCT-2 lines lacked surface immunoglobulins and reacted with a monoclonal antibody (MAb) specific for hamster T cells. Some were positive for OKIa1. None of them expressed HTLV structural antigens (p19 and p24) or virus particles, but they contained HTLV-I proviral DNA monoclonally. By immunochemical analysis of the labelled cell antigens, sera from adult T-cell leukemia (ATL) patients reacted with the two polypeptides, p37 and p40, which may not be viral structural proteins and still remain to be characterized. HCT-1 and HCT-2 cells were transplantable into newborn hamsters, pre-treated with anti-hamster thymocyte serum and non-treated, respectively, producing diffuse malignant lymphoma. These findings indicated that HTLV-I not only immortalized but also transformed hamster T cells non-productively.
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PMID:Transformation of hamster spleen lymphocytes by human T-cell leukemia virus type I. 300 33

The recent report by Koprowski et al. that human T-cell lymphotropic retroviruses (HTLVs) may be involved in the development of multiple sclerosis (MS) has aroused much interest. The report was based largely on immunological evidence, using enzyme-linked immunosorbent assays (ELISAs) with viral antigens or disrupted virions. We have accordingly sought confirmation by screening sera and cerebrospinal fluid (CSF) samples from MS patients against cell lines infected respectively with adult T-cell leukaemia (ATL) virus (ATLV/HTLV-I) of Japanese cells (MT-1 and MT-2 lines), our own isolate from British black patients with ATL, the MoT cell line which produce HTLV-II, and our own T-cell line containing a local isolate of acquired immune deficiency syndrome (AIDS) virus (C-LAV/HTLV-III). We have failed to find antibodies against these retroviruses in the sera or CSF. Furthermore, neither virus could be isolated from the peripheral white blood cells of two MS patients.
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PMID:Lack of evidence for involvement of known human retroviruses in multiple sclerosis. 301 52

Antibodies reactive against human T-cell leukemia virus I (HTLV-I) were detected by indirect immunofluorescence assay using MT-2 as target cells, enzyme linked immunosorbent assay screen and competition assay, and Western blot analysis in three sera (one collected in 1979) from a captive gorilla which developed diffuse histiocytic lymphoma in 1983. The sera from four other healthy gorillas housed separately were HTLV-I antibody negative. All sera were negative for HTLV-III antibodies by enzyme linked immunosorbent assay. Southern blot analysis of DNA from lymphoma tissue after digestion with BamHI and using complete HTLV-I genome probe gave one 10-kilobase fragment and a characteristic 1.05-kilobase internal fragment detected in all known HTLV-I isolates. These results indicate that the gorilla was infected with HTLV-I or a closely related simian virus several years before the development of lymphoma.
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PMID:Human T-cell leukemia virus I provirus and antibodies in a captive gorilla with non-Hodgkin's lymphoma. 301 96

We determined the nucleotide sequence of a region between the gag and pol genes of a replication-competent proviral clone of a human T-cell leukemia virus type I (HTLV-I) from MT-2 cells. This region overlapping the gag and pol genes contains an open reading frame with a different phase from others. The deduced amino acid sequences show significant homology with the known protease gene of other retroviruses, and harbors highly conserved amino acid sequences that are well conserved in other retroviral protease domains. These results indicate that this open reading frame encodes a HTLV-I protease.
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PMID:Identification of a protease gene of human T-cell leukemia virus type I (HTLV-I) and its structural comparison. 302 Nov 21

We isolated the full length provirus of human T cell leukaemia virus type I (HTLV-I) from MT-2, a lymphoid cell line producing HTLV-I. In three non-lymphoid cell lines (COS7, human osteosarcoma HOS cells, and HeLa) this provirus expressed a trans-acting activity after co-transfection with a recombinant plasmid carrying a bacterial chloramphenicol acetyltransferase gene under the control of a long terminal repeat of HTLV-I provirus. The trans-acting protein p40 was detected by immunoprecipitation in transfected HOS cells. Structural proteins of HTLV-I, the gag and env products, were also formed and processed in the same manner as observed in MT-2 cells. In transfected HeLa cells, the p40 protein was mainly localized in the nucleus, while other structural proteins were detected in the cytoplasm and/or the membrane by indirect immunofluorescence. Syncytium formation was observed in HeLa cells after transfection. These results demonstrated that non-lymphoid cells could produce the major proteins of HTLV-I after DNA transfection of the cloned provirus.
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PMID:Expression of a provirus of human T cell leukaemia virus type I by DNA transfection. 302 87

The location of the pX gene products in human T-cell leukemia virus type 1-producing cells, MT-2 and HUT 102, was studied by immunoelectron microscopy using the direct and indirect peroxidase-labeled antibody methods. Fab'-peroxidase conjugates were prepared for the direct method with a maleimide compound from antisera to the carboxy-terminal region of the pX gene products. Positive immunostaining in MT-2 cells was detected in the endoplasmic reticulum, the outer and inner leaflets of the nuclear membrane, and inside their cisternae, but not in the plasma membrane and viral particles. Staining in the nucleus was faint. On the other hand, positive immunostaining in HUT 102 cells was detected diffusely in the euchromatin regions of the nucleus but not in the nucleoli, nuclear envelope, and cellular membrane systems. The location of the positive immunostaining in the HUT 102 nuclei was reconfirmed by the reaction in isolated nuclei. On the basis of both the immunoelectron microscopic and immunoblotting analyses of the pX gene products, it is suggested that the Mr 40,000 to 42,000 protein (p40x) is localized mainly in the euchromatin regions of the nuclei of human T-cell leukemia virus type 1-producing cells, and the Mr 68,000 protein (p68x) is localized mainly in the nuclear envelope and the endoplasmic reticulum of MT-2 cells. p68x detected in MT-2 cells with the anti-p40x serum was deduced to be a protein consisting of p40x and a part of env gene products and to share epitopes in common with p40x.
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PMID:Immunoelectron microscopic localization of the pX gene products in human T-cell leukemia virus type 1-producing cells. 303 May 42

The in vitro transformation of normal T-lymphocytes by human T-cell leukemia/lymphoma virus (HTLV-I) is possible utilizing cocultivation techniques. We now report on a quantitative assay for HTLV-I transformation. Transformed cell lines were produced by cocultivation of either preactivated (phytohemagglutinin and T-cell growth factor) or nonactivated peripheral blood mononuclear cells with an equal number of lethally irradiated HTLV-I-positive donor cells (MT-2). After 14 days in liquid culture, transformed cells were plated in a 2-layer soft agarose system with or without T-cell growth factor (TCGF). Colony formation among 50 normal controls was observed at varying efficiencies with a mean number of 179 colonies (range, 6-599) in the presence of TCGF (up to a 2-log difference). The day 14 T-cell cultures demonstrated relatively low colony-forming efficiencies (less than or equal to 0.1%) and enhanced colony formation in the presence of TCGF. Day 14 after cocultivation was chosen for this assay based on a dose-response relationship between colony formation and the virus-positive donor cell inoculum and the known kinetics of colony growth of normal activated T-cells. An analysis of individual colonies indicated that they were of target cell origin and HTLV-I positive. Recombinant beta-interferon in increasing concentrations caused a decrease in colony formation as measured in this assay. Long-term cell cultures (2-18 months) showed higher colony-forming efficiencies (up to 1.0%) which were not enhanced by TCGF. The ability to quantitatively evaluate transformation via colony counts will provide an opportunity to study differences in transforming efficiencies attributable to varying target cells, donor cells, or blocking factors such as interferons, drugs, or anti-HTLV-I antibodies.
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PMID:Quantitative assay of human T-cell leukemia/lymphoma virus transformation. 303 23

Infection with human T-cell leukaemia/lymphoma (HTLV-I) preferentially affects T cells of the OKT-4 phenotype. The aim of the present study was to determine whether distinct T-cell subsets exhibit differences in susceptibility to virus infection. T cells from peripheral blood were separated according to cell densities by 7-step Percoll gradients. Separated T-cell subpopulations were infected with HTLV-I, using cocultivation with irradiated virus producer MT-2 cell line. Percentages of HTLV-I-infected cells and their phenotypes were assayed by immunofluorescence assay (IFA), using highly specific mouse monoclonal antibody directed against HTLV-I P-19 core protein, and other surface markers. The results showed that different T-cell subpopulations were susceptible to HTLV-I infection with the exception of large granular lymphocytes (LGL) which exhibit high cell-mediated natural cytotoxicity (CMNC).
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PMID:Differential susceptibility of human mononuclear cells to infection with HTLV-I. 303 35


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