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)

Several isolates of human T-cell leukemia/lymphoma virus (HTLV) were transmitted to normal human T cells obtained from the umbilical cord blood of newborns. T cells from seven specimens were immortalized by infection with different HTLV isolates and their properties were compared with those of activated uninfected normal T cells grown in the presence of T-cell growth factor (TCGF) and with those of HTLV-positive neoplastic T-cell lines derived from patients with T-cell malignancies. The HTLV-infected cells generally belonged to a class of mature T cells (OKT4+ and Leu 3A+) and differed from the normal uninfected cells in that they could be propagated in culture indefinitely; possessed altered morphology, including convoluted nuclei and some bi- and multinucleated giant cells; formed large clumps in culture; demonstrated a diminished requirement for TCGF; had an increased density of TCGF receptors; often became completely independent of exogenous TCGF; and expressed HLA-DR determinants. These properties of the HTLV-infected cord blood T cells contrasted to those of uncultured cord blood T cells and of cord blood cells stimulated with mitogen and grown with TCGF but resembled the characteristics of T-cell lines established previously from patients with HTLV-associated T-cell malignancies. This in vitro system offers a unique opportunity to study the basic mechanism involved in abnormal growth and neoplastic transformation of a specific class of human T cells.
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PMID:Transformation of human umbilical cord blood T cells by human T-cell leukemia/lymphoma virus. 660 73

Human T-cell growth factor (TCGF) has been isolated from conditioned media of the Jurkat T-leukemia cell line. Using a high-efficiency isolation procedure involving hollow fiber concentration, gel filtration and 3 steps of reverse-phase HPLC we obtained 100 to 600 pmol TCGF per liter of conditioned medium. Jurkat cell-derived TCGF (jTCGF) has a molecular weight of 15,750. The amino acid composition of jTCGF agrees well with that derived from the cDNA sequence coding for this protein (Taniguchi et al, Nature 302, 305, 1983). jTCGF is highly active in vitro in stimulating the proliferation of T-cells as measured by 3H-thymidine incorporation into DNA (half-maximal stimulation with 3 fmol/100 microliters well).
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PMID:Isolation and partial characterization of human T-cell growth factor. 660 52

Peripheral blood lymphocytes from seven patients with adult T-cell leukemia (ATL) were found to lack PHA-responsiveness. However, in most of the cases, minute but distinct proliferation could be induced and maintained by human spleen cell conditioned medium containing PHA or by a combination of PHA and conditioned medium of gibbon cell line, MLA-144 (MLA-144 CM). These results indicate that the lack of response to mitogens of ATL cells might be attributed not only to the failure of these cells to produce T-cell growth factor (TCGF) upon activation, but also to their poor responsiveness to TCGF. Furthermore, a direct proliferative response to mitogen-free MLA-144 CM was shown in two out of seven patients; these two patients experienced rapidly progressive clinical courses. This observation raises the possibility that TCGF promotes the growth of ATL cells in vivo, and is related to the clinical course of the disease.
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PMID:Correlation of aberrant proliferation with T-cell growth factor in adult T-cell leukemia cells. 661 Jun 22

To isolate a stable tumor cell line capable of producing human interleukin 2 (IL-2; formerly referred to as T cell growth factor), 16 human T and B leukemia cell lines were screened for constitutive and mitogen-stimulated IL-2 production. We found that the T cell leukemia line designated Jurkat-FHCRC produced > 200 U/ml of IL-2 activity after a 24-h stimulation with T cell mitogens. Peak mitogen-induced IL-2 activity was found in supernates harvested from 24-h Jurkat-FHCRC cell cultures stimulated with either 1% phytohemagglutinin or 20 microgram/ml concanavalin A. Addition of the fatty acid derivative phorbol myristate acetate to mitogen-stimulated cultures increased Jurkat-FHCRC IL-2 production to concentrations > 400 U/ml. IL-2 activity observed in such cases represented between 100--300 times that produced in conventional cultures of mitogen- or alloantigen-stimulated normal human peripheral blood or splenic lymphocytes. Jurkat-FHCRC-derived conditioned medium demonstrated equal capacity to promote the sustained in vitro proliferation of either murine or human activated T cell lines confirming the ability of Jurkat-FHCRC cells to produce human IL-2. These studies identify a new source of human IL-2 and establish a valuable reagent for the isolation and further molecular characterization of this immunoregulatory molecule.
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PMID:Biochemical and biological characterization of lymphocyte regulatory molecules. V. Identification of an interleukin 2-producing human leukemia T cell line. 677 51

Mononuclear blood cells from patients with different types of leukemia, and from controls as well as cells from established lymphoblastic cell lines were analyzed with respect to terminal transferase (TdT) activity and T-cell growth factor (TCGF; Interleukin 2, IL-2), to determine the significance of TCGF production and response as functional markers for human leukemias. The data obtained so far suggest that the aberrant proliferation and lack of maturation observed in these leukemias may be associated with or be the result of a break-down in cellular-mediated control of proliferation.
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PMID:T-cell growth factor (interleukin 2) and terminal transferase activity in human leukemias and lymphoblastic cell lines. 694 97

Two permanent T-cell leukemia lines designated KH-1 and KH-2 were established from the peripheral blood of a 9-year-old boy with acute lymphoblastic leukemia and a 47-year-old man with adult T-cell leukemia (ATL). No T-cell growth factor was used. KH-1 cells grew as single cells and KH-2 cells formed clusters in suspension culture. Erosette formation, the absence of immunoglobulin determinants and Epstein-Barr-virus-associated nuclear antigen, and the presence of T-cell antigens revealed by monoclonal antibodies were characteristics of these cell lines as in other established T-cell leukemia lines. Chromosome analysis at the beginning revealed mosaic presence of cells with 46, XY, t(8q+; 15q-) and 46, XY which was later completely replaced by the latter karyotype in KH-1, and abnormal karyotype, 47, XY, +3, t (8q-; 10p+) was maintained throughout the period of in vitro passage in KH-2. The donor patient of KH-2 formerly lived in the south-western part of Japan where ATL is considered endemic and numerous type-C virus particles were detected electron microscopically, in KH-2 cell pellets.
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PMID:Establishment and cytological characteristics of two in vitro T-cell lines derived from a child with acute lymphatic leukemia and a man with adult T-cell leukemia in Japan. 698 37

A chimeric toxin has been constructed by fusion of a gene encoding human interleukin 4 (hIL4) to a gene encoding a mutant form of Pseudomonas exotoxin A (PE) which cannot bind to its receptors (PE4E). The chimeric gene was expressed in Escherichia coli where large amounts of the chimeric toxin, hIL4-PE4E, was produced. Purified hIL4-PE4E was very cytotoxic to cancer cell lines of both hematopoietic and solid tumor origin. In the HUT 102 T cell leukemia and Daudi B cell lymphoma cell lines, protein synthesis was inhibited by 50% (ID50) at a hIL4-PE4E concentration of 2 and 7 ng/ml (25 and 86 pM, respectively). hIL4-PE4E was also very cytotoxic to cell lines derived from carcinomas of the colon, breast, stomach, liver, adrenals, and prostate, as well as melanoma and epidermoid carcinoma, indicating that hIL4 receptors are widely expressed on human malignancies. We also found that human phytohemagglutinin-activated peripheral blood lymphocytes were extremely sensitive to hIL4-PE4E with an ID50 of 0.2 ng/ml (2.5 pM). The cytotoxic action of hIL4-PE4E was specific because it was blocked by an excess of hIL4 and not of human interleukin 2. In addition, hIL4-PE4ED553, an enzymatically inactive form of the chimeric toxin, was not cytotoxic. These results suggest that the hIL4 receptor may be a target for therapy in malignant and immunologic disorders using hIL4 chimeric toxin.
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PMID:A wide range of human cancers express interleukin 4 (IL4) receptors that can be targeted with chimeric toxin composed of IL4 and Pseudomonas exotoxin. 831 73

Despite intensive conditioning and marrow purging, leukemia relapse frequently follows autologous BMT for acute lymphoblastic leukemia. To generate antileukemic immunologic activity, we performed a phase I study using recombinant human interleukin 2 given immediately posttransplantation. This early period was chosen because of low disease burden; therefore induced in vivo effector:target cell ratios might be most favorable. IL-2 was given by continuous infusion (96 hr/week x 3 weeks) beginning day +1. Fourteen patients with high-risk ALL were treated at 0.5, 1.0, and 2.0 x 10(6) U/m2/day IL-2. The clinical toxicity, hemopoietic recovery, and immune activation in the IL-2-treated patients was compared with that in a group of autologous BMT patients receiving no IL-2. The patients receiving IL-2 had a trend toward earlier neutrophil, platelet, and RBC recovery plus earlier hospital discharge versus non-IL-2 controls. However, IL-2 plus the inherent toxicity of transplantation often produced hepatic, pulmonary, and renal toxicity. Assessment of immune activation induced by in vivo IL-2 (following 3 weeks of IL-2) showed proliferation of CD8+ T cells having in vitro cytotoxicity against the Nalm-6 ALL cell line in most patients. Little enhancement of natural killer activity by immunophenotype or cytotoxicity against K562 cells was observed. IL-2 given immediately post-BMT induces infrequent but significant toxicity at lower doses than in the non-BMT setting. This toxicity may result from pre-BMT conditioning in conjunction with T cell activation. The immunotherapeutic potential, dose, and schedule of IL-2 following BMT require further study along with measures to reduce its toxicity.
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PMID:Interleukin 2 immediately after autologous bone marrow transplantation for acute lymphoblastic leukemia--a phase I study. 842 66

The interleukin-2 receptor alpha chain (IL-2R alpha) is a T-cell growth factor receptor and is known to be induced in helper T cells by infection with human T-cell leukaemia virus type-1 (HTLV-1). The Rex protein of HTLV-1 has been shown to stabilize IL-2R alpha mRNA. Although the 3' untranslated region of many RNA has been regarded as a key element for stabilization, we found that the first 300 bases of the IL-2R alpha protein coding sequence were necessary for stabilization of the mRNA. As the first 201 bases were not sufficient for this effect, we conclude that the bases at position 201-300 downstream of the AUG start are important for stabilization.
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PMID:The 5' coding sequence of IL-2 receptor alpha chain mRNA mediates mRNA stabilization by HTLV-1 Rex. 856 20

To detect chromosomal abnormalities in prodromal phase of adult T-cell leukemia (ATL), we established a clonal culture method for human T-lymphotropic virus type I (HTLV-I) infected T-cells in methylcellulose containing recombinant human interleukin 2 (rhIL-2). We tried to analyze chromosomes of 187 colonies (4, 23, 69, 74, and 17, from HTLV-I-uninfected normal T-cells, HTLV-I-Infected normal T-cells, HTLV-I carriers, smoldering ATL, and chronic ATL, respectively), using chromosomal banding methods. In the prodromal group, 53% of colonies (84/160) (36/69, 37/74, 11/17 in HTLV-I carriers, smoldering ATLs, and chronic ATL, respectively) had chromosomal abnormal clones. In HTLV-I carriers, multiple clones with simple chromosomal abnormalities were observed. In more progressed chronic ATL, more complex chromosomal abnormalities were detected, and specific colonies were selected. Thus, colonies in the prodromal phase of ATL are characterized by cytogenetical clonal evolution and clonal changes.
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PMID:High rate of chromosomal abnormalities in HTLV-I-infected T-cell colonies derived from prodromal phase of adult T-cell leukemia: a study of IL-2-stimulated colony formation in methylcellulose. 997 53


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