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 expression of the leukemia inhibitory factor/D factor (LIF) gene in human T-cell leukemia virus type 1 infected T-cell lines was examined. Human T-cell leukemia virus type 1 infected T-cell lines MT-1, MT-2, H89-59, H89-79, and H109 expressed LIF mRNA, but the T-cell lines MOLT-4 and TALL-1 did not. LIF mRNA expression was enhanced by interleukin 2 or 12-O-tetradecanoylphorbol-13-acetate in MT-2 cells. The biological activity of LIF was detected in culture medium enhanced by interleukin 2 in MT-2 cells. The expression of LIF mRNA was suppressed by 1 alpha,25-dihydroxyvitamin D3 and dexamethasone. These results imply that the expression of the LIF gene is involved in the development of hypercalcemia and abnormalities of the immune system observed in patients with adult T-cell leukemia.
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PMID:Expression and regulation of the leukemia inhibitory factor/D factor gene in human T-cell leukemia virus type 1 infected T-cell lines. 145 88

There is now a substantial body of evidence that the immune system can help eradicate leukemia. While alloreactive T cells may play this role after allogeneic bone marrow transplants (BMT), T-cells may also exist which are able to recognize processed leukemia specific antigens such as mutant oncogenes/fusion proteins. In addition, a contribution may come from major histocompatibility complex unrestricted but leukemia-selective killing by natural killer/activated killer cells. These effector mechanisms may be augmented by administration of interleukin 2 after chemotherapy or autologous BMT. Finally, techniques of gene marking may help to determine more accurately the site and characteristics of minimal residual disease and thereby improve the targeting of immune mediated eradication of leukemia.
Leukemia 1992
PMID:Immunotherapy of leukemia. 154 41

A unique feature of both human T-cell leukemia virus type I (HTLV-I) carriers and subjects with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a chronic inflammatory disease of the nervous system, is the presence of large numbers of activated T cells that spontaneously proliferate in vitro. We have investigated the mechanisms of T-cell activation by HTLV-I in freshly isolated blood T cells and in naturally infected T-cell clones obtained by direct single-cell cloning from patients with HAM/TSP. Both CD4+ and CD8+ HTLV-I-infected T-cell clones showed the unusual ability to proliferate in the absence of exogenous interleukin 2 (IL-2). Nevertheless, HTLV-I-infected clones were not transformed, as they required periodic restimulation with phytohemagglutinin and feeder cells for long-term growth. Irradiated or fixed HTLV-I-infected clones were found to induce the proliferation of blood T cells when cocultured, which we refer to as THTLV-1-T cell activation. This THTLV-1-T cell-mediated activation was blocked by monoclonal antibodies (mAbs) against CD2/lymphocyte function-associated molecule 3 (LFA-3), LFA-1/intercellular cell-adhesion molecule (ICAM), and the IL-2 receptor but not by mAbs against class I or class II major histocompatibility complex molecules, HTLV-I gp46, or a high-titer HAM/TSP serum. Spontaneous proliferation of blood T cells from HAM/TSP patients could also be inhibited by mAbs to CD2/LFA-3, LFA-1/ICAM and to the IL-2 receptor (CD25). These results show at the clonal level that HTLV-I infection induces T-cell activation and that such activated T cells can in turn stimulate noninfected T cells by cognate THTLV-1-T cell interactions involving the CD2 pathway.
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PMID:T-cell activation by autologous human T-cell leukemia virus type I-infected T-cell clones. 154 69

Adoptive immunotherapy with interleukin 2-induced lymphokine-activated killer (LAK) cells or tumor-infiltrating lymphocytes (TIL) and the induction of anti-tumor responses by IL-2 alone having proven to be promising approaches in cancer therapy. The present study investigated the cytotoxicity of LAK cells towards human leukemia cells. LAK cells were generated by culturing peripheral blood mononuclear cells from normal donors for six days in the presence of recombinant interleukin 2 (IL-2). Cytotoxicity was evaluated using a standard 4-h chromium-release assay. A significant lysis of fresh uncultured leukemia cells by IL-2-activated killer cells could be detected in 77 of 150 leukemias examined. The mean Cr-release was 35.7 +/- 12.9% in the LAK cell-sensitive vs 9.9 +/- 5.9% in the resistant leukemias. With a view to the therapeutic utilization of the LAK-cell system, we attempted to improve the efficiency of its cytotoxic mechanisms. Combined application of IL-2 and interferon-alpha, interferon-gamma, or tumor necrosis factor-alpha in cultures for generation of activated killer cells significantly improved the effectiveness of cytotoxic mechanisms. Our results suggest that the performance of adoptive immunotherapy with ex vivo-activated LAK cells and the in vivo induction of cytotoxic immune responses by IL-2 alone or combined with different lymphokines or cytokines may be of value in treating human leukemia, especially when the tumor burden is low, e.g. during maintenance therapy or after bone marrow transplantation to eliminate minimal residual disease or in early relapse.
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PMID:Cytotoxicity of interleukin 2-induced lymphokine-activated killer (LAK) cells against human leukemia and augmentation of killing by interferons and tumor necrosis factor. 156 Jun 76

Dipyridamole strongly inhibited spontaneous in vitro proliferation of peripheral blood mononuclear cells from patients with acute myelogenous leukaemia (n = 9), chronic myelogenous leukaemia in first chronic phase (n = 4) and blast phase (n = 1). Theophyllamine and verapamil also inhibited proliferation of leukaemia cells from all patients except the CML patient in blast phase where only minimal inhibition was seen. Only dipyridamole caused strong inhibition in concentrations corresponding to the therapeutic serum level, and this inhibition was not influenced by the presence of high levels of interleukin 2.
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PMID:Effect of dipyridamole, theophyllamine and verapamil on spontaneous in vitro proliferation of myelogenous leukaemia cells. 158 6

The effect of phorbol myristate acetate (PMA) on the expression of interleukin 2 receptors (IL-2R), production of IL-2 and IL-2-dependent proliferation of acute lymphoblastic leukemia T cells (T-ALL cells) from 10 patients was studied. First, the effect of PMA on the expression of cell surface markers was assessed: a decrease of CD3 and CD4, and an enhanced expression of CD8 molecule were observed on T-ALL cells. Moreover, PMA exhibited an heterogenous effect on various activation-associated molecules such as a decreased expression of transferrin receptor and T10 molecule and an induced expression of 4F2 and CD9 molecules. It is known that functional high-affinity IL-2R are composed of at least two IL2 binding molecules, the alpha (p55) and beta (p70) chains. We found that PMA induced the expression of both IL-2R alpha and IL-2R beta chains, as well as IL-2 production by T-ALL cells. These effects were time- and dose-dependent. Cross-linking experiments with 125I-labelled recombinant IL-2 (125I-rIL-2) revealed both p55 (IL-R alpha) and p70 (IL-2R beta) IL-2-binding polypeptides, whereas binding equilibrium assays on PMA-treated cells demonstrated the presence of a low number (31-413) of high-affinity binding sites/cell in five out of six cases analysed, as well as intermediate affinity IL-2R (1234-3919 sites/cell) in four out of six cases, according to the time of incubation with PMA. In two cases tested high-affinity IL-2R on PMA-treated T-ALL cells could internalize 125I-rIL-2 at 37 degrees C. PMA alone enhanced the spontaneous proliferation of T-ALL cells in three cases, whereas a clear synergy between IL-2 and PMA could be detected in three patients' cells. Moreover, exogenous rIL-2 enhanced cell proliferation of PMA-preincubated T-ALL cells in four cases studied. Taken together, these observations indicate that a short-term incubation of T-ALL cells with PMA can activate the IL-2/IL-2R system on these cells without inducing strong modifications of their differentiation status. These results thus suggest that this system may be involved in the proliferation process of some activated immature T cells.
Leukemia 1992 Apr
PMID:Phorbol myristate acetate-induced expression of high-affinity interleukin 2 receptors and production of interleukin 2 by human acute lymphoblastic leukemia T cells. 158 92

We have recently reported that methionine adenosyltransferase (MAT) in resting human peripheral blood T-cells is primarily present in the form of a precursor which we named lambda. This protein decreases upon cell stimulation, as both MAT activity and the amount of the catalytic alpha/alpha' subunits of the enzyme increase. When resting cells are activated by phytohemagglutinin, the decrease in lambda and increase in alpha/alpha' occurs after interleukin 2 (IL-2) production and before DNA synthesis. The human T-leukemia cell line, Jurkat, is unique in its ability to produce IL-2 in response to exogenous stimuli such as T-cell mitogens and therefore provides a convenient model for studying biochemical reactions involved in T-cell activation. In this study the regulation of MAT activity and S-adenosylmethionine (AdoMet) in resting and activated Jurkat cells was investigated. Here we report that MAT activity in unstimulated Jurkat cells is about 10- and 3-fold higher than the activity in resting and activated peripheral blood mononuclear cells, respectively. Activation of Jurkat cells with phytohemagglutinin resulted in increased IL-2-production, but not an increase in MAT activity. Identical results were obtained using freshly isolated cells from acute lymphoblastic leukemia patients. AdoMet utilization and pool size were approximately 3- and 10-fold higher, respectively, in Jurkat cells compared to peripheral blood mononuclear cells, and both parameters were unaffected by phytohemagglutinin stimulation. Jurkat MAT was determined to be structurally indistinguishable from enzyme from T- or B-leukemia cells but was different from resting, normal T-cells in that it lacked the lambda form. Furthermore, unlike MAT in resting T-cells, the relative amounts of the alpha, alpha', and beta subunits of the enzyme did not change throughout the course of IL-2 induction. We conclude that AdoMet metabolism and MAT activity in Jurkat cells are constitutively high and that induction of IL-2 synthesis in these cells is independent of changes in AdoMet synthesis or turnover. The lack of the lambda form and the difference in MAT regulation between leukemic T-cells and peripheral blood mononuclear cells may be exploited in the design of specific chemotherapeutic agents.
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PMID:Induction of interleukin 2 production but not methionine adenosyltransferase activity or S-adenosylmethionine turnover in Jurkat T-cells. 159 94

In this paper we review some of the preclinical findings which have led us to believe that immunotherapy with interleukin 2 (IL2)/lymphokine activated killer (LAK) cells may be a feasible approach in the management of acute myeloid leukemia. The main clinical and biological results so far obtained with IL2 treatment, and the currently ongoing protocols and strategies are discussed.
Leukemia 1992
PMID:Interleukin 2 (IL2) in the management of acute myeloid leukemia: clinical and biological findings. 160 6

The murine leukemia viruses (MuLV) designated LP-BM5 induce an immunodeficiency disease in susceptible strains of mice with many features in common to human acquired immunodeficiency syndrome (AIDS), including lymphadenopathy and profound immunodeficiency associated with enhanced susceptibility to infection and terminal B cell lymphomas. The disease, termed murine AIDS (MAIDS), crucially depends on the presence of B cells and CD4+ T cells, suggesting that mutual activation of these two cell types is central in the pathogenesis of the immunodeficiency syndrome. Cyclosporin A (CsA), whose immunosuppressive effect is attributed mainly to inhibition of interleukin 2 and interferon-gamma expression, interferes in T-B cell interactions. Here we show that chronic treatment with CsA (40 or 60 mg/kg/day) before and after infection with LP-BM5 MuLV protects against the development of immunodeficiency disease as assessed by functional, serological and histopathological criteria. The protection was not complete, suggesting both CsA-sensitive and CsA-resistant components to the pathogenesis of this syndrome, and was found to be independent of ecotropic MuLV expression. These results underline immunopathological mechanisms in the progression of immune abnormalities in MAIDS that are susceptible to inhibition of CsA and may serve as an experimental basis for developing a treatment of the human disorder with immunomodulators.
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PMID:Protective effect of cyclosporin A on immune abnormalities observed in the murine acquired immunodeficiency syndrome. 164 58

T cell depletion has decreased the incidence and severity of graft-versus-host disease following transplantation of allogeneic bone marrow. In the treatment of leukemia, decreased GVHD has often been associated with diminished antileukemia or graft-versus-leukemia (GVL) reactivity resulting in higher relapse rates. However, we have not seen a loss of the GVL effect following transplantation of marrow grafts depleted of CD3+ T cells. This suggests that non-T-cell effectors may play a role in preventing leukemic relapse. To study whether natural killer and lymphokine-activated killer (LAK) activity in BM was compromised by T cell depletion, the effect of T-cell-specific monoclonal antibodies against CD3 and CD6 determinants alone, or in combination, on the generation and expansion of NK/LAK cells was examined in vitro and compared to the effect of T depletion on mitogen-driven T cell proliferation. Limiting dilution analysis revealed that T depletion with CD3 and/or CD6 specific antibodies significantly reduced the number of proliferating T lymphocytes but did not significantly affect the frequency of cells able to expand and mediate LAK activity. Bone marrow, depleted of CD3+ or CD6+ T cells, generated levels of LAK activity equivalent to non-T-cell-depleted bone marrow following long-term culture in recombinant interleukin 2. CD3- NKH-1+ cells were the predominant population in rIL-2 expanded marrow cultures prior to transplant and in the peripheral blood of patients who had received a CD3-depleted marrow graft 21-65 days earlier. These studies show that it is possible to selectively reduce GVH-reactive T cells in allogeneic bone marrow while retaining non-T-effector cells with potential to mediate an antileukemia effect in vivo.
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PMID:Preservation of lymphokine-activated killer activity following T cell depletion of human bone marrow. 169 9


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