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)

Human T-cell leukemia virus type-I (HTLV-I) has a post-transcriptional regulatory gene termed rex. We have designed the rex gene to express in E. coli. Synthesis of rex protein, p27rex, was examined by immunoblot analysis using anti-p27rex antibody. No difference in electrophoretic mobility in NaDadSO4-PAGE was observed between p27rex expressed in E. coli and in an HTLV-I-infected cell line, MT-2. Slower migration of p27rex, corresponding to a 27-kD protein, in NaDodSO4-PAGE when compared with the calculated molecular weight from the amino acid sequence (Mr = 20,367) is suggested to be caused not by post-translational modification, but by the intrinsic nature of the protein, which is rich in proline and arginine.
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PMID:Expression of post-transcriptional regulatory gene of HTLV-I, rex, in Escherichia coli. 269 88

Expression of human T-cell leukemia virus type I (HTLV-I) is not detectable by immunofluorescence analysis or RNA blot analysis in most fresh peripheral blood mononuclear cells of patients with adult T-cell leukemia or of asymptomatic HTLV-I carriers. However, in this work, mRNA for the HTLV-I tax1/rex1 genes was detected in fresh peripheral blood mononuclear cells of adult T-cell leukemia patients and asymptomatic HTLV-I carriers by using reverse transcription followed by the polymerase chain reaction. By using fresh peripheral blood mononuclear cells, the expression of tax1/rex1 mRNA was detected in five of the six adult T-cell leukemia patients and four of the eight HTLV-I carriers examined. The amounts of tax1/rex1 mRNA detected corresponded to approximately 10(5) to 10(6) times less than that in the HTLV-I-infected MT-2 cell line. These results indicate that, in some individuals infected with HTLV-I, the provirus in circulating blood cells is transcribed in vivo. Thus the expression of viral antigens in circulating blood cells in vivo is suggested.
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PMID:Detection of mRNA for the tax1/rex1 gene of human T-cell leukemia virus type I in fresh peripheral blood mononuclear cells of adult T-cell leukemia patients and viral carriers by using the polymerase chain reaction. 278 12

Co-cultivation of thymus and spleen cells of Fisher and Lewis rats with lethally irradiated MT-2 cells harboring human T-cell leukemia virus type I (HTLV-I) resulted in the establishment of lymphoid cell lines, FIRT-1, FIRS-1, LERT-1, and LERS-1, respectively. Cells of these cell lines had rat T-cell characters as demonstrated by the positive reaction to monoclonal antibodies (MAbs) to rat T cell antigens (Thy 1 and pan T). They lacked surface immunoglobulins and strongly expressed rat interleukin-2 receptor antigen (Tac) and Ia antigen. Karyotypic analysis revealed that they had the normal rat karyotype in early cultures, but showed marked aneuploidy after long cultivation. None of them expressed HTLV gag proteins (p19 and p24) or virus particles, but they contained HTLV-I proviral DNA monoclonally and weakly expressed pX gene products (p40x). They were not transplantable into syngeneic newborn rats.
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PMID:Immortalization of rat spleen and thymus T cells by human T-cell leukemia virus type I. 278 56

Cynomolgus monkeys and squirrel monkeys were inoculated with autologous lymphoid cell lines immortalized by and producing human T-cell leukemia virus type-I (HTLV-I) in order to serve as an animal model of adult T-cell leukemia (ATL). The autologous cell lines were established from peripheral blood mononuclear cells (PBMC) from each monkey by co-cultivation with lethally irradiated MT-2 cells producing HTLV-I. All of these cell lines, which had monkey karyotypes, grew continuously without addition of interleukin-2 (IL-2) and expressed virus-specific proteins of HTLV-I and IL-2 receptor. After inoculation with the autologous cell lines, specific antibodies against HTLV-I proteins could be detected in their plasma, and transformed HTLV-I-infected cells could be recovered from their peripheral blood for at least 6 months. However, no signs of ATL have been observed to data, i.e. 2 years after inoculation.
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PMID:Experimental inoculation of monkeys with autologous lymphoid cell lines immortalized by and producing human T-cell leukemia virus type-I. 287 91

A serological study of antibody to adult T-cell leukemia-virus-associated antigen (anti-HTLV-I antibody) was made in 170 cases of various hematological diseases at Shikoku Cancer Center Hospital. The titer of anti-HTLV-I antibody was determined by indirect immunofluorescence using the MT-2 cell line. Two of two patients with ATL were positive for antibody. In non-Hodgkin's lymphoma, six of 18 cases of T-cell phenotype were positive (33%), while two of 29 cases of B-cell phenotype were antibody-positive (7%). Some cases of leukemia and aplastic anemia, who had received multiple blood transfusions, were found to be seropositive. Our results suggest that anti-HTLV-I antibody may be related to non-Hodgkin's lymphoma with T-cell phenotype as well as ATL.
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PMID:[Serological study of the antibody to the adult T-cell leukemia-virus-associated antigen in various hematological diseases]. 287 48

The effects of 1 alpha, 25-dihydroxyvitamin D3 [1,25-(OH)2D3] on proliferation and de novo DNA synthesis were studied in the following established human leukemia cell lines: lymphoblastic T-cell lines HPB-ALL, CCRF-HSB-2, p12/lchikawa, and HPB-MLT; adult T-cell leukemia- (ATL) and human lymphotropic virus type I (HTLV-I)-infected T-cell lines HUT102, HUT-102B2, MT-1, MT-2, MJ, C2/MJ, KH-2, KH-2Lo, HPB-CTL-1, and ATN-C1; ATL-derived B-cell lines ATL-BK9 and ATL-BK10; lymphoblastic B-cell line Daudi; and myelocytic-monocytic lineage cell lines HL-60 and U937. 1,25(OH)2D3 inhibited proliferation and de novo DNA synthesis of phytohemagglutinin-P-activated T-cells and certain established HTLV-I-positive T-cells. However, it did not inhibit immature lymphoblastic T- and B-cells or ATL-derived B-cells. The degree of inhibition depended on the dose of 1,25(OH)2D3 and the heterogeneity of the established HTLV-I-positive T-cells. KH-2 and subclone KH-2Lo were markedly inhibited, and HPB-CTL-1 was moderately inhibited. Marked inhibition of DNA synthesis in KH-2Lo cells was observed in the proliferative phase of the cell cycle. No inhibition of KH-2Lo proliferation or expression of interleukin-2 and transferrin receptor was noted after removal of 1,25(OH)2D3 from the culture medium. 1,25(OH)2D3 inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced multinucleated cell formation of various HTLV-I-positive T-cell lines and TPA-induced HTLV-I p19 expression in KH-2Lo cells.
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PMID:Effect of 1 alpha,25-dihydroxyvitamin D3 on proliferation of activated T-cells and established human lymphotropic virus type I-positive T-cell lines. 288 43

T4 subpopulation of T lymphocytes is the preferential target of infection with human T leukemia/lymphoma virus of subgroup I (HTLV-I). In this study we attempt to determine whether different T-cell subsets exhibit differences in susceptibility to virus infection. T cells from cord or peripheral blood were separated according to cell densities and T-cell surface markers by Percoll gradient and Sepharose anti-Fab immunoadsorbent affinity column (IAC), respectively. Separated T-cell subpopulations were infected with HTLV-I, by means of co-cultivation with irradiated virus producer cell lines (MT-2, TK). Percentages of HTLV-I-infected cells were assayed by immunofluorescence assay (IFA), using highly specific mouse monoclonal antibody (MAb) directed against HTLV-I p19 core protein. The results showed that different T-cell subpopulations separated either by Percoll or by IAC were susceptible to HTLV-I infection with the exception of large granular lymphocytes (LGL), which exhibit high cell-mediated natural cytotoxicity (CMNC). The susceptibility to HTLV-I infection of T cells with CMNC activity was further studied on established cell clones with LGL morphology. The results showed again that these cells were resistant to the virus infection. The present studies indicate that different T-cell subpopulations, irrespective of their size and of cell-surface markers, are susceptible to HTLV-I infection, with the exception of functionally mature LGL or of immortalized LGL clones.
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PMID:In vitro susceptibility of different human T-cell subpopulations and resistance of large granular lymphocytes to HTLV-I infection. 288 78

Protection against human T-cell leukemia virus type-I (HTLV-I) infection in cynomolgus monkeys, achieved by immunizing the animals with env gene products of HTLV-I produced in Escherichia coli, was evaluated. Four monkeys that had been immunized with the env product produced antibody against HTLV-I gp68 and gp46, and their sera were found to cause strong inhibition of syncytium formation of a cat fibroblast cell line induced by HTLV-I. Immunized and non-immunized monkeys were challenged with live MT-2 cells, a high HTLV-I-producer cell line. After challenge, all the control non-immunized monkeys were infected with HTLV-I, as judged by the frequent detection of HTLV-I-antigens in cultures of their peripheral blood mononuclear cells (PBMC), whereas no antigens were recovered from PBMC of immunized monkeys. These results indicate that humoral immunity against HTLV-I-envelope protein elicited by immunization with the polypeptides synthesized in bacteria protected the monkeys against primary infection with HTLV-I.
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PMID:Protection of cynomolgus monkeys against infection by human T-cell leukemia virus type-I by immunization with viral env gene products produced in Escherichia coli. 288 18

Gangliosides (GM3, GD3, GM2, gangliotetraose-series gangliosides) and their asialo derivatives of several adult T-cell leukemia (ATL) cell lines (ATL-1K, ATL-3I, ATL-5S, and MT-2 cells) and the lymphocytes from a patient with ATL were quantified by highly sensitive enzyme-immunostaining on silica gel thin layer chromatograms using specific antiglycolipid antibodies. GM2 and GD3 gangliosides and asialo GM1 (GA1) newly appeared in all cultured ATL cells and the lymphocytes from patients with ATL but not in normal human T-lymphocyte-rich fraction. Gangliotetraose-series gangliosides, GM1a, GD1a and GD1b, were also found in cultured ATL cells, but were not detected in normal human lymphocytes or the lymphocytes of a patient with ATL. Quantitative immunostaining analysis of GM2, GD3 gangliosides and GA1 in T-cell lines from non ATL leukemia (Molt-3, CEM and Jurkat) revealed GM2 gangliosides in all the T-cells from non ATL tested and GA1 in Jurkat cells, but no GD3 ganglioside was found in the non ATL leukemia cells tested. The above results indicate that ganglioside GD3 may be a T-cell glycosphingolipid antigen associated with ATL, and ganglioside GM2 and GA1 may be useful as surface markers related with ATL, as well as T-cell lymphoma. The contents of GA1, GM3, GD3, GM2 and gangliotetraose-series gangliosides in ATL cells were all different, even though all the cells used have a common antigen reactive with monoclonal OKT-4 antibody, indicating that there are several subsets of human inducer/helper T-cells, which possess different metabolism and expression of gangliosides.
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PMID:Aberrant expression of ganglioside and asialoglycosphingolipid antigens in adult T-cell leukemia cells. 289 Jun 14

The MT-2, derived from an adult T-cell leukaemia (ATL) cell, the Molt-4F, a human T-cell line, and the Isk, an EB virus-transformed B-cell line, were found to have high-affinity receptors for somatostatin, a cyclic tetradecapeptide that inhibits the release of substances such as growth hormone, TSH, glucagon, insulin, secretin, gastrin and cholecystokinin. The quantity of radioactivity bound varied linearly with the number of cells, and was displaced by non-radioactive somatostatin in a concentration-dependent manner. Specific binding of 125I-somatostatin was time- and temperature-dependent and at 22 degrees reached equilibrium within 120 min. Scatchard analysis demonstrated one class of specific-binding sites on MT-2 cells, Isk cells and Molt-4F cells that had respective densities and dissociation constants of 109 pM and 0.64 nM, 102 pM and 1.1 nM, and 5.8 pM and 0.22 nM.
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PMID:Identification of lymphoid cell lines bearing receptors for somatostatin. 289 85


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