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)

Human T-cell leukemia virus type I (HTLV-I) infection is emerging as an important complication in HIV infection and AIDS in injecting drug users. HIV-1 and HTLV-I share a common host in CD4+ T lymphocytes. However, the result of HIV-1 infection is the decimation of this cell population, whereas a hallmark of HTLV-I infection is the inappropriate proliferation of infected cells. Combined epidemiologic data suggest that HTLV-I infection is enhanced during concurrent HIV-1/HTLV-I infection; however, there are currently no in vitro studies focusing on the effects of drugs of abuse on retrovirus coinfection. We have found that in an in vitro coinfection system (HIV-1 + HTLV-I), morphine treatment further enhanced the levels of HTLV-I p19. In addition, indicators of in vitro infection by cell-free HIV-1 were reduced by morphine treatment in both single and dual in vitro infection experiments. Interleukin 2 levels in the affected cultures were found to increase with combined HTLV-I infection and morphine treatment. These in vitro results indicate the need to further explore the activity of HTLV-I within opiate-treated cells, as this oncoretrovirus appears to be especially sensitive to morphine-induced alterations to its host cell environment.
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PMID:Morphine effects on HTLV-I infection in the presence or absence of concurrent HIV-1 infection. 1023 11

The initiation of DNA synthesis and secretion of Interleukin 2 (IL-2) was measured in isolated rat splenic lymphocytes following activation with Concanavalin A (ConA). The extent of 3H-thymidine incorporation into activated cells was tested when cultured with various concentrations of Adrenocorticotropic hormone (ACTH). A paradoxical dose-response curve resulted when ACTH caused a biphasic response of augmenting and inhibiting 3H-thymidine uptake in lymphocytes depending on the hormone concentration. Low levels of ACTH (0.001-1-nM) augmented 3H-thymidine uptake and high levels (10-1000 nM) reversed the effect. The optimal ACTH concentration was 10 pM ACTH in the presence of 5 ug/ml ConA and there was no ACTH effect on quiescent cells (no ConA). Conditioned media from splenic lymphocytes treated with various concentrations of ConA or ACTH was tested for increased uptake of 3H-thymidine by the IL-2 growth dependent Cytotoxic T Lymphocyte Leukemia (CTLL-2) cells. ConA conditioned medium could sustain the CTLL-2 cells indicating the presence of IL-2. Conditioned medium from splenic lymphocytes treated with both ConA and 100 pM ACTH further increased CTLL-2 cell proliferation indicating an additional increase of IL-2 secretion. The identity of IL-2 was confirmed by using an anti-rat IL-2 antibody to neutralize the growth potential of the conditioned medium. ACTH alone had no effect on the CTLL-2 cell proliferation indicating the effect is due solely to induced IL-2 found in the conditioned medium. IL-2 levels in the conditioned media were quantitated by ELISA assay; splenic lymphocytes produced 4.2 ng/ml to ConA only, 19.2 ng/ml in ConA plus 10 nM ACTH, and no detectable IL-2 at ConA plus 10 uM ACTH. These results demonstrated that ACTH modulates IL-2 secretion from activated lymphocytes, which is both biphasic and concentration dependent.
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PMID:Adrenocorticotropic hormone controls Concanavalin A activation of rat lymphocytes by modulating IL-2 production. 1104 99

In this study, in vitro and in vivo antitumor effects of mononuclear cells from human umbilical cord blood cells (UCBCs) and peripheral blood stem cells (PBCs) harvest obtained by leukapheresis were compared. Interleukin 2 (IL-2)-activated mononuclear cells from UCBCs showed increased cytotoxicity against K562 and Raji hematopoietic malignant cells compared with PBCs (P < 0.05). After IL-2 activation, both UCBCs and PBCs showed significant cytotoxicity against MDA-231 human breast cancer cells. The UCBC population involved in this antitumor activity appeared to be CD56+ natural killer precursors. The cytotoxicity of UCBCs was inhibited in the absence of Ca2+ (P < 0.05), supporting a perforin/granzyme-mediated target of cell lysis. In addition, antibodies to Fas ligand blocked cytotoxic activity, suggesting that some of the antitumor cytotoxicity was Fas ligand mediated. In vivo antitumor effects of UCBCs and PBCs were studied using a human leukemic cell-bearing severe combined immunodeficient mouse model. There was a significant increase in the survival of K562 leukemia-bearing mice that also received 5 million in vitro IL-2-activated UCBCs or PBCs i.v. on days 3 and day 5 after tumor transplantation compared with untreated mice (P < 0.01). Similar antitumor cytotoxicity of UCBCs and PBCs was also observed against MDA-231 human breast cancer grown in severe combined immunodeficient mice (P < 0.01). These studies suggest that IL-2-activated UCBCs may be a useful source of cellular therapy for patients with hematological malignancies and breast cancer.
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PMID:Antitumor therapeutic potential of activated human umbilical cord blood cells against leukemia and breast cancer. 1110 53

Allogeneic bone marrow transplantation (BMT) is a treatment modality with the potential of curing otherwise lethal diseases. The predominant indications for BMT are haematological malignancies. In BMT alloreactivity plays a pivotal role for the outcome. Graft-versus-host disease (GvHD) and graft-versus-leukaemia (GvL) are correlated manifestations of alloreactivity. Severe GvHD is one of the main causes of morbidity and mortality post-BMT. In the absence of GvL the risk of relapse is high. The main effector cells are T lymphocytes. Donor leukocyte infusion (DLI) for treatment of leukaemic relapse after BMT can induce durable remissions. DLI causes GvHD in the majority of the responding patients. However, a GvL effect may be present without evidence of GvHD and vise versa. The importance of alloreactivity for the treatment outcome prompted the interest for a predictive test of alloreactivity. Interleukin 2 (IL-2) producing helper T lymphocyte precursor (HTLp) frequencies determined by limiting dilution analysis (LDA) in the graft-versus-host direction were explored. The HTLp assay was optimized and the sources of error minimized to ensure sensitive and reproducible results. The IL-2 dependent cell line, CTLL-2 was optimized to detect 0.6 pg IL-2. UV-B irradiation of the cells was demonstrated to effectively terminate proliferation of the responder cells and thus allow IL-2 to be detected in the whole culture volume. The design of the assay was explored by Monte Carlo simulations resulting in a design yielding frequencies with a coefficient of variation of 20% in the range of 1:20,000-1:1,000,000. The influence of autoreactivity of the donor and recipient cells was minimized as well as the risk of the stimulator cells producing IL-2. The HTLp frequencies correlated with the degree of human leukocyte antigen (HLA) disparity and the assays were able to detect minor histocompatibility antigen mismatches. The HTLp frequencies of 28 HLA-identical sibling BMT pairs and 20 HLA-matched unrelated and partially HLA-matched related BMT pairs were determined. HTLp frequencies from the HLA-identical sibling BMT pairs had a median of 1:557,362 (range 1:9.511 to < 1:2,500,000). The HTLp frequencies from the HLA-matched unrelated and partially HLA-matched related BMT pairs had a median of 1:88,110 (range 1:4.139-1:736,123). Analysis of the HLA-identical sibling BMT pairs in a high and a low HTLp frequency group above and below 1:500,000 showed a trend towards a higher risk of acute GvHD > or = grade II and a significantly higher risk of chronic GvHD in the high HTLp frequency group. This group had a significantly lower risk of relapse as well as a significantly better overall survival and leukaemia free survival. The HLA-matched unrelated and partially HLA-matched related BMT pairs were split evenly in a high and a low HTLp frequency group above and below 1:90,000. There was a significantly higher risk of acute GvHD > or = grade II and a trend towards a higher treatment related mortality (TRM) in the high HTLp frequency group. There were no differences in chronic GvHD, risk of relapse, overall survival and leukaemia free survival. Analyzing all 48 patients the risk of acute GvHD > or = grade II and TRM was significantly higher with HTLp frequencies > 1:100,000 and there was a trend towards a higher risk of relapse with low HTLp frequencies < 1:400,000. Patients in the intermediate HTLp frequency group 1:100,000-1:400,000 had a trend towards improved survival. The HTLp frequency seems to detect clinically significant differences in alloreactivity, that can be useful in donor selection, graft-engineering, T cell add-back and the pharmacological immunosuppression used after BMT.
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PMID:Alloreactivity and the predictive value of anti-recipient specific interleukin 2 producing helper T lymphocyte precursor frequencies for alloreactivity after bone marrow transplantation. 1206 93

Interleukin 2 and interleukin 15 (IL2 and IL15, respectively) provide quite distinct contributions to T-cell-mediated immunity, despite having similar receptor composition and signaling machinery. As most of the proposed mechanisms underlying this apparent paradox attribute key significance to the individual alpha-chains of IL2 and IL15 receptors, we investigated the spatial organization of the receptors IL2Ralpha and IL15Ralpha at the nanometer scale expressed on a human CD4+ leukemia T cell line using single-molecule-sensitive near-field scanning optical microscopy (NSOM). In agreement with previous findings, we here confirm clustering of IL2Ralpha and IL15Ralpha at the submicron scale. In addition to clustering, our single-molecule data reveal that a non-negligible percentage of the receptors are organized as monomers. Only a minor fraction of IL2Ralpha molecules reside outside the clustered domains, whereas approximately 30% of IL15Ralpha molecules organize as monomers or small clusters, excluded from the main domain regions. Interestingly, we also found that the packing densities per unit area of both IL2Ralpha and IL15Ralpha domains remained constant, suggesting a 'building block' type of assembly involving repeated structures and composition. Finally, dual-color NSOM demonstrated co-clustering of the two alpha-chains. Our results should aid understanding the action of the IL2R-IL15R system in T cell function and also might contribute to the more rationale design of IL2R- or IL15R-targeted immunotherapy agents for treating human leukemia.
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PMID:Nanometer-scale organization of the alpha subunits of the receptors for IL2 and IL15 in human T lymphoma cells. 1828 85


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