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)

The purposes of this work are to: review the biological activities of Interleukin-2 (IL-2); evaluate the reported therapeutic benefits and toxicity of IL-2/lymphokine activated killer (LAK) cells; and project the role of IL-2/LAK cells in cancer therapy. Interleukin-2 is a glycoprotein lymphokine (mw 15,000) produced naturally by mitogen or antigen stimulated T-lymphocytes. The activities of IL-2 include: enhancement of IL-2 receptor positive T-lymphocytes and a variety of other in vitro and in vivo alterations of T cell function. The IL-2 gene has been cloned from the Jurkat leukemia cell line and expressed by recombinant biotechnology in an E. coli vector. In vitro incubation of IL-2 with selected T-lymphocytes results in the formation of lymphocyte activated killer (LAK) cells. Rosenberg and colleagues, in 1983, demonstrated that both exogenous IL-2 and LAK cells were needed in order to get maximum tumor regression in a murine model and later humans. Patients selected for IL-2/LAK cell therapy have clinical metastases or advanced unresectable cancers. Almost all patients treated demonstrate some toxic effects, including chills, fever, nausea, vomiting, diarrhea and hepatic dysfunction. Approximately 75 percent of the patients have profound hypotension and require intensive nursing care. A review of the literature indicates that tumor responsiveness will range from negligible (adenocarcinoma of the lung with metastases) to a 30+ percent response in renal cell carcinoma when complete and partial responders are totalled. Interleukin-2/LAK cell therapy has promise for some wide spread tumors for which no other therapy is available.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interleukin-2 and lymphokine activated killer cells: promises and cautions. 264 90

We have shown that the patients with myelogenous leukemia display several defects in the NK cell lytic mechanism. However, this cytotoxic defect could be corrected after culture of effector cells from these patients with IL-2. The cytotoxic potential of IL-2-activated killer cells could be further augmented by treatment with OKT3 monoclonal antibody. Interleukin-2-activated lymphocytes were effective in killing not only a variety of tumor cell lines, but also autologous leukemic cells. Moreover, these cells were not stationary, but proliferated actively in culture with IL-2. Characterization studies, using the monoclonal antibodies against NK cell (CD16 and NKH1/Leu-19) or T-cell (CD3 and CD5) surface molecules showed that the antileukemia-directed cytotoxic cells were NK cells and not T-cells. In contrast, the T-cells (and not NK cells) exhibited an ability to down-regulate clonogenic activity of hematopoietic progenitors and to inhibit proliferation of bone marrow cells. Our data suggest that adoptive therapy with highly-enriched IL-2-activated NK cells may result in more powerful anti-leukemia effect. Alternatively, activated NK cells may be effective in eradication of leukemic cells from bone marrow for autologous bone marrow transplantation purposes.
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PMID:Cytotoxicity and clinical application of activated NK cells. 278 21

The role of membrane fluidity in the process of signal transduction after binding of Interleukin-2 (Il-2) to its specific cell-surface receptor was investigated in lymphocytes from normal donors and patients with Chronic Lymphocytic Leukemia (CLL). Membrane fluidity was assessed by fluorescence polarization analysis of the apolar fluorophor 1,6-diphenyl-1, 3, 5-hexatrien (DPH) incorporated in the lipid core of the cell membrane. Phytohemagglutinin (PHA) stimulation of lymphocytes for 72h disclosed marked membrane fluidization in normal lymphocytes without affecting lipid phase separation lacking in leukemic cells. Binding of Il-2 induced a significant decrease of the thermotropic transition temperature and overall membrane fluidization within 1h. These effects were not observed in CLL lymphocytes. Results are discussed in terms of defective transmembrane signalling in leukemic cells and pathogenetic implications for uncoupling from proliferation and differentiation signals in the development of leukemia.
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PMID:Lack of dynamic lipid changes after binding of interleukin 2 in chronic lymphatic leukemia lymphocytes indicates defective transmembrane signalling. 278 88

Interleukin-2 (IL-2) is a lymphokine synthesized by T cells following activation. Resting T cells do not express IL-2 receptors, but receptors are rapidly expressed on T cells following interaction of the antigen-specific T-cell receptor complex with appropriately processed and presented antigens. Anti-Tac, a monoclonal antibody that recognized the IL-2 receptor, has been used to purify the receptor. The recognized the IL-2 receptor, has been used to purify the receptor. The receptor is a 55-Kd glycoprotein comprised of 272 amino acids including a single 19-amino transmembrane domain and a short intracytoplasmic domain composed of 13 amino acids at the carboxy terminus. Normal resting T cells and most leukemic T-cell populations examined did not express IL-2 receptors; however, the leukemic cells of all patients with human T-cell lymphotrophic virus (HTLV-I)-associated adult T-cell leukemia (ATL) expressed the Tac antigen. In HTLV-I-infected cells, the 42-Kd long open reading frame (tat) protein encoded in part by the tat region of HTLV-I may act as a transacting activator that induces transcription of the IL-2 receptor gene, thus providing an explanation for the constant association of HTLV-I infection of lymphoid cells and IL-2 receptor expression. The constant display of large numbers of IL-2 receptors which may be aberrant in the ATL cells may play a role in the uncontrolled growth of these leukemic T cells. Patients with the Tac-positive ATL are being treated with both unmodified and toxin-conjugated forms of anti-Tac monoclonal antibody directed toward this growth factor receptor.
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PMID:The interleukin-2 receptor on normal and malignant lymphocytes. 288 69

Human T-cell leukemia virus (HTLV)-infected cell lines derived from adult T-cell leukemia (ATL) express constitutively the receptor for Interleukin-2 (IL-2-R) and the associated antigen (Tac antigen). In contrast, the same antigen is transiently expressed by normal T-cells only after immune stimulation. Recently, it was reported that the constitutively expressed Tac antigen on ATL cells and cell lines was not down-regulated or modulated by anti-Tac antibody. Since the antigen was modulated on normal mitogen- or alloantigen-stimulated T-cells, we postulated that the regulation of IL-2-R may be abnormal on ATL cells; the synthesis of IL-2-R is continuously stimulated in these cells. A unique HTLV/ATLV(-) cell line (YT) derived from a child with acute lymphoblastic leukemia was found to express low levels of Tac antigen that could be enhanced by various stimuli, including conditioned medium (CM) derived from normal lymphocytes, but not by lectins (PHA, Con A). Of particular interest, the exposure of YT cells to CM from ATL cell lines with helper phenotype revealed the presence of factor(s) (ATL-derived factor, ADF) that augmented the synthesis and expression of IL-2-R/Tac antigen on YT cells and promoted YT cell growth. CM from HTLV(-) leukemia cell lines lacked both IL-2-R augmenting activity and a growth promoting activity. Immunoaffinity-purified IL-2 and recombinant gamma interferon also lacked IL-2-R augmenting activity. Moreover, the physicochemical analysis with Fast protein liquid chromatography (FPLC) revealed that ADF was quite different in pI point from the IL-2-R augmenting activity in CM from normal lymphocytes. These results suggested that ADF is a unique product of HTLV(+) cells. The possible relationship between ADF production, HTLV infection, and the abnormal expression of IL-2-R is suggested, and these abnormalities may be advantageous for the leukemogenesis and abnormal growth of ATL.
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PMID:Adult T leukemia cells produce a lymphokine that augments interleukin 2 receptor expression. 297 23

Interleukin-2 (IL-2) is a lymphokine synthesized by some T-cells following activation. Resting T-cells do not express IL-2 receptors, but receptors are rapidly expressed on T-cells following interaction of antigens, mitogens, or monoclonal antibodies with the antigen-specific T-cell receptor complex. Using anti-Tac, a monoclonal antibody that recognizes the IL-2 receptor, the receptor has been purified and shown to be a Mr 33,000 peptide that is posttranslationally glycosylated to a Mr 55,000 mature form. Normal resting T-cells and most leukemic T-cell populations do not express IL-2 receptors; however, the leukemic cells of the 11 patients examined who had human T-cell lymphotropic virus-associated adult T-cell leukemia expressed the Tac antigen. In human T-cell lymphotropic virus-I infected cells, the Mr 42,000 long open reading frame protein encoded in part by the pX region of this virus may act as a transacting transcriptional activator that induces IL-2 receptor gene transcription, thus providing an explanation for the constant association of IL-2 receptor expression with adult T-cell lymphotropic virus-I infection of lymphoid cells. The constant expression of large numbers of IL-2 receptors which may be aberrant may play a role in the uncontrolled growth of adult T-cell leukemia cells. Two patients with Tac-positive adult T-cell leukemia have been treated with the anti-Tac. One of the patients had 6- and 3-mo remissions of his leukemia following two courses of therapy with this monoclonal antibody directed toward this growth factor receptor.
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PMID:Interleukin 2 receptor (Tac antigen) expression in HTLV-I-associated adult T-cell leukemia. 299 Jun 87

Interleukin-2 (IL-2) is a lymphokine synthesized by T cells following activation. Resting T cells do not express IL-2 receptors, but receptors are rapidly expressed on T cells following interaction of the antigen-specific T-cell-receptor complex with appropriately processed and presented antigens. Anti-Tac, a monoclonal antibody that recognizes the IL-2 receptor, has been used to purify the receptor. The receptor is a 55-kDa glycoprotein comprised of 251 amino acids including a single 19-amino transmembrane domain and a short intracytoplasmic domain composed of 13 amino acids at the carboxy terminus. Normal resting T cells and most leukemic T-cell populations examined did not express IL-2 receptors; however, the leukemic cells of all patients with human T-cell lymphotrophic virus (HTLV-I)-associated adult T-cell leukemia (ATL) expressed the Tac antigen. In HTLV-I-infected cells, the 42-kDa long open reading frame (tat) protein encoded in part by the tat region of HTLV-I may act as a transacting activator that induces transcription of the IL-2-receptor gene, thus providing an explanation for the constant association of HTLV-I infection of lymphoid cells and IL-2-receptor expression. The constant display of large numbers of IL-2 receptors which may be aberrant in the ATL cells may play a role in the uncontrolled growth of these leukemic T cells. Patients with the Tac-positive ATL are being treated with both unmodified and toxin-conjugated forms of anti-Tac monoclonal antibody directed toward this growth factor receptor.
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PMID:The interleukin-2 receptor on malignant cells: a target for diagnosis and therapy. 301 74

Interleukin-2 (IL-2) in combination with the IL-2 receptor has an essential role in antigen-stimulated proliferation of T lymphocytes. It has been proposed that the constitutive expression of the IL-2 receptor on adult T-cell leukaemia (ATL) cells may be associated with transformation of T cells. Although we and others have isolated complementary DNA clones encoding a protein that binds IL-2, formal proof that this protein is the IL-2 receptor requires demonstration of IL-2-dependent growth stimulation of cells expressing the protein. In addition, a functional assay system other than binding of IL-2 is required to investigate the molecular mechanism of signal transmission through the IL-2 receptor using artificially mutated cDNA. The IL-2 receptor expressed in non-lymphoid cells by cDNA transfection did not mediate a growth signal, implying that lymphoid cells expressing the functional receptor might have specific accessory molecule(s) for signal transmission by the receptor. Therefore, we established a line of IL-2-dependent mouse cells (CT/hR) expressing both murine (endogenous) and human IL-2 receptors. Here, by blocking the endogenous mouse IL-2 receptors with monoclonal antibodies, we show that the human IL-2 receptor of CT/hR cells is functionally active. Although CT/hR expressed the human IL-2 receptor constitutively, growth of these cells was strictly dependent on IL-2, indicating that uncontrolled over-expression of the IL-2 receptor was not by itself sufficient for T-cell transformation.
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PMID:Expression of functional human interleukin-2 receptor in mouse T cells by cDNA transfection. 308 15

Interleukin-2 (IL-2) for a long time has been considered as a T-cell specific growth factor which acts through distinct surface receptors present on activated, but not on resting, T-lymphocytes. Recently it has been shown that activated murine and human B-cells also express IL-2 receptors and respond to IL-2 with an increase of DNA synthesis. Some human B-cell malignancies have been reported to react with anti-IL-2 receptor antibodies, but no response to IL-2 has been documented in these cases. Here, in five of 11 B-cell leukemia/lymphoma cases, we identified cells which not only express the IL-2 receptor, but also respond to IL-2 stimulation, as shown by a marked increase of 3H-thymidine incorporation and by differentiation of lymphoma cells. The IL-2-induced 3H-thymidine uptake was completely blocked by a monoclonal antibody to IL-2 receptor, which indicates that IL-2 acted directly through functional IL-2 receptors.
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PMID:Malignant B-cells have receptors for and respond to interleukin-2. 310 Aug 85

The expression of several lymphokine gene is characterized by a common pattern of induction, suppression and superinduction. This pattern was studied at the level of cellular mRNA in the mouse T-lymphoma cell line EL4, the human T-leukemia line Jurkat and in normal human peripheral blood lymphocytes. Lymphokine mRNA was induced by stimulating the cells with the phorbol diester PMA (TPA), with or without T-lymphocyte mitogens. The induction of Interleukin-2, Interferon gamma and the Colony Stimulating Factor for granulocytes and macrophages was suppressed by Cyclosporin A at moderate concns. Furthermore, these mRNAs accumulated to extraordinarily high levels (superinduction) if the protein synthesis inhibitor cycloheximide was added during transcription. Superinduction was not due to an increased rate of transcription. CsA interrupted ongoing transcription of IL2 by a mechanism not dependent on the induction of a new protein. The co-ordinate regulation of these genes strongly suggests that common intracellular signals mediate their expression.
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PMID:Induction, suppression and superinduction of lymphokine mRNA in T lymphocytes. 311 4


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