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 IL-9 is a T cell-derived lymphokine that is abundantly expressed upon activation with mitogens. The observation that IL-9 induction peaks as late as 28 h after stimulation suggested the involvement of secondary signals in this process. The finding reported here that IL-9 expression is blocked by cycloheximide strongly supports this hypothesis. Moreover, we identify IL-2 as the critical element controlling IL-9 expression in T cells. We show (i) that anti-IL-2R antibodies block IL-9 expression in T cells stimulated with PMA and anti-CD3 and (ii) that IL-2, of a panel of cytokines, is the only molecule that synergizes with PMA for IL-9 induction. The latter finding is confirmed in a T cell leukemia line. Finally, we demonstrate that IL-2 plays a regulatory role in the induction of other cytokines, such as IL-4, IL-5, IL-6, and granulocyte/macrophage-CSF, in fresh peripheral T cells.
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PMID:IL-2 dependence of IL-9 expression in human T lymphocytes. 153 52

Reducing the graft-vs-host disease (GVHD)-promoting capacity of allogeneic T cells while maintaining alloengraftment and graft-vs-leukemia effects remains an important but elusive goal in clinical bone marrow transplantation (BMT). We have recently demonstrated that a short course of high dose IL-2 administered at the time of BMT has a powerful protective effect against GVHD mortality in mice. This short course of IL-2 is able to protect mice from both acute and chronic GVHD without sacrificing alloengraftment or graft-vs-leukemia effects of allogeneic T cells. Because the early administration of IL-2 seems to be crucial for this effect, we have studied the early lymphoid repopulation events after lethal irradiation and allogeneic BMT. These studies show that there are consistent delays in splenic repopulation by allogeneic cells after BMT in IL-2-treated animals compared with their untreated cohorts. Even greater percent reductions were seen in donor splenic T cell populations in the first few days after BMT in IL-2-treated animals. Splenic cells with the CD3+CD4-CD8- phenotype were increased in IL-2 treated animals at days 3 and 4 after BMT. This phenotype resembles that of bone marrow-derived cells which have been previously shown to inhibit GVHD, suggesting a possible mechanism for the protective effect of IL-2.
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PMID:Mechanism of protection from graft-versus-host disease mortality by IL-2. III. Early reductions in donor T cell subsets and expansion of a CD3+CD4-CD8- cell population. 153 24

Recent studies performed in Seattle, USA have suggested that pretransplant assignment of high or low donor alloreactivity may predict acute graft-versus-host disease (aGvHD) after allogeneic HLA identical marrow transplantation for acute leukaemia. The effect of such pretransplant assignment was studied in a Scandinavian population of 114 consecutive transplantations for acute and chronic leukaemias in 1st remission (n = 74) or chronic phase (n = 40) performed between 1975 and 1989. The selected cut-off value for discriminating between donors of high and low responding capacity (DRC) was based on distribution plots of results from the pretransplant mixed lymphocyte culture (MLC) and chosen as the median value (80% normalized response). Then 57 donors were assigned with high DRC and 57 donors assigned with low DRC. Kaplan-Meier estimates of the probability of patients to develop Grade II or higher aGvHD in receipt of high or low responder donor transplants were compared by univariant analysis. The patients in first remission or chronic phase transplanted with bone marrow from donors assigned as high or low responders had a 36.1% and 10.6% risk for aGvHD, respectively, a difference found to be significant by log rank test (chi-squared = 10.1, d.f. = 1, P = 0.0015). Subsequent studies of the cellular and humoral requirements for this predictive response of donor cells, by blocking with cytokine specific antibodies, addition of excess of recombinant human cytokines and scanning of lymphocyte subsets during the response, showed that the response against pool cells mostly depended upon IL-2 responding cells with the phenotype CD3+, CD4+, CD8-, CD25+, CD16-. It is concluded that prospective studies of alloreactivity as a risk factor should be performed to confirm the above findings.
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PMID:A study of donor alloreactivity, which may predict acute graft-versus-host disease in HLA identical bone marrow transplantations for early leukaemia. 153 90

A diazirine derivative of cyclosporine (PL-CS) was used to photolabel recombinant human cyclophilin (rhCyp), the cytosolic receptor for the immunosuppressant cyclosporine. The affinity of PL-CS for rhCyp and the immunosuppressive activity were 10-fold reduced as compared to cyclosporine A. Whereas cyclosporine immunosuppression was fully reversible, UV cross-linking of PL-CS resulted in permanent inhibition of lymphocyte activation as shown by proliferation of anti-CD3 stimulated human peripheral lymphocyte, interleukin (IL)-2 gene transcription and IL-2 synthesis in the human T-leukemia cell line Jurkat. In vivo photolabeling of viable Jurkat cells revealed that a 21-kDa complex was the major radiolabeled product which was identified as a cyclophilin-cyclosporine complex. In addition, cyclophilin B (25 kDa) and proteins of an unidentified nature at 40, 46 and 60 kDa were observed in Jurkat cells. The cyclosporine-resistant human fibroblast cell line MRC5 displayed a different labeling pattern: cyclophilin B (25 kDa) and a 65-kDa protein were the major labeled products, while the 46- and 60-kDa components were not detectable and cyclophilin was only faintly labeled. In summary, covalent cyclosporine binding caused irreversible lymphocyte inactivation and revealed in addition to cyclophilin other specifically labeled proteins in lymphoid cells. The role and identity of these proteins is presently unknown.
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PMID:Covalent binding of cyclosporine inhibits irreversibly T-lymphocyte activation. 155 93

Members of the Ets family of proto-oncogenes encode sequence-specific transcription factors that bind to a purine-rich motif centered around a conserved GGA trinucleotide. Ets binding sites have been identified in the transcriptional regulatory regions of multiple T cell genes including the T cell receptor alpha and beta (TCR-alpha and -beta) enhancers and the IL-2 enhancer, as well as in the enhancers of several T cell-trophic viruses including Maloney sarcoma virus, human leukemia virus type 1, and human immunodeficiency virus-2. T cells express multiple members of the Ets gene family including Ets-1, Ets-2, GABP alpha, Elf-1, and Fli-1. The different patterns of expression and protein-protein interactions of these different Ets family members undoubtedly contribute to their ability to specifically regulate distinct sets of T cell genes. However, previous studies have suggested that different Ets family members might also display distinct DNA binding specificities. In this report, we have examined the DNA binding characteristics of two Ets family members, Ets-1 and Elf-1, that are highly expressed in T cells. The results demonstrate that the minimal DNA binding domain of these proteins consists of adjacent basic and putative alpha-helical regions that are conserved in all of the known Ets family members. Both regions are required for DNA binding activity. In vitro binding studies demonstrated that Ets-1 and Elf-1 display distinct DNA binding specificities, and, thereby interact preferentially with different naturally occurring Ets binding sites. A comparison of known Ets binding sites identified three nucleotides at the 3' end of these sequences that control the differential binding of the Ets-1 and Elf-1 proteins. These results are consistent with a model in which different Ets family members regulate the expression of different T cell genes by binding preferentially to purine-rich sequences that share a GGA core motif, but contain distinct flanking sequences.
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PMID:Evolutionarily conserved Ets family members display distinct DNA binding specificities. 156 4

The expression of interleukin-2 receptors (IL-2R) was examined in 328 adult patients with non-T-cell (non-T) acute leukaemia and blast crisis of chronic myelocytic leukaemia (CML.BC) using two monoclonal antibodies, anti-Tac for IL-2R alpha chain (IL-2R alpha) and Mik beta 1 for IL-2R beta chain (IL-2R beta). Leukaemic cells in the following cases were positive for anti-Tac; 28/192 of acute myelocytic leukaemia (AML), 24/44 CML-BC, 4/28 CD19(+)CD10(-) acute lymphoblastic leukaemia (ALL), and 20/64 common ALL (c-ALL). IL-2R beta was not detected on leukaemic cells of any case examined. Eleven of IL-2R alpha(+) AML were derived from myelodysplastic syndrome. None of the IL-2R alpha positive leukaemic cells responded to exogenous recombinant human IL-2 (rhIL-2) in culture. In addition, IL-2R alpha expression on non-T leukaemic cells was closely correlated with coexpressing different lineage markers and the presence of the Philadelphia abnormality. Marked increase of serum soluble IL-2R alpha was demonstrated in the IL-2R alpha(+) patients examined. Clinically, the IL-2R alpha(+) patients showed significantly lower response to chemotherapy and poorer prognosis than IL-2R alpha(-) patients. Our results clearly indicate the diagnostic importance of IL-2R alpha expression in non-T acute leukaemia with a close relation to the particular cellular characteristics and the prognosis.
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PMID:Diagnostic and clinical importance of interleukin-2 receptor alpha chain expression on non-T-cell acute leukaemia cells. 158 Dec 11

A murine model of minimal residual disease (MRD) was established utilizing the murine B-cell leukemia (BCL1). BALB/c mice inoculated with up to 10(4) BCL1 were cured (greater than 1 year disease-free survival) following administration of intraperitoneal injections of recombinant human IL-2 (10(5) Cetus units x 3/day intraperitoneally x 5 days). Lethally irradiated BALB/c or (BALB/c x C57BL/6)F1 recipients were reconstituted with syngeneic bone marrow cells or T-cell-depleted C57BL/6 bone marrow cells contaminated with 10(4), 10(5), or 10(6) BCL1 to simulate quantitative MRD. Untreated mice died of typical leukemia without exception, whereas a substantial anti-leukemia effect was noted in mice treated by allogeneic spleen cells, IL-2, or particularly a combination of allogeneic spleen cells and IL-2 given concomitantly. Increments of donor-type spleen cells (10(6), 10(7), and 5 x 10(7)) or IL-2 (10(4) U x 2/day x 3 days) were given alone or in combination on days +1, +5, and +9 following Thy 1.2-depleted allogeneic BMT. All adoptive recipients of 10(5) spleen cells obtained from mice inoculated with 10(4) and 10(5) BCL1 treated by a combination of allogeneic spleen cells and IL-2 showed no evidence of disease greater than 100 days. The antitumor effects of allogeneic spleen cells alone and IL-2 alone were also highly significant, although not totally curative in all mice. Allogeneic spleen cells seemed more effective as compared with low dose IL-2 (3 courses of 2 x 10(4) U x 2/day x 3 days). None of the recipients of 10(6) BCL1 could be completely cured under the experimental conditions described without additional chemotherapy, although significant antitumor effects could again be documented following concomitant administration of allogeneic spleen cells and IL-2. Using an experimental model of autologous BMT, recipients of 10(3) tumor cells could also be cured following transplantation of syngeneic spleen cells by high-dose IL-2 (10(5) U x 3/day x 5 days) given at the time lymphocytes were present, optimally at 3 weeks following BMT. Based on encouraging results from experiments using our animal model of MRD, in conjunction with autologous and allogeneic BMT, pilot clinical trials are currently underway, investigating the effect of cytokine-mediated immunotherapy (CMI) in MRD following conventional and high-dose cytoreductive anticancer therapy in conjunction with ABMT. In addition, we are attempting induction of cell-mediated cytokine-activated immunotherapy (CCI) in conjunction with autologous and allogeneic BMT. Prospective randomized clinical trials and longer observation periods are required to assess the full efficacy of these new therapeutic modalities.
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PMID:Immunotherapy of minimal residual disease by immunocompetent lymphocytes and their activation by cytokines. 158 31

From a plaque biopsy of a patient with mycosis fungoides, two different continuous cell lines were established by including both IL-2 and IL-4 in the culture medium. Both continuous cell lines appeared with characteristic chromosome markers after approximately 40 cell population doublings. The initial karyotype recognized in T cells from the skin biopsy was 46,XY and the karyotypes of the continuous cell strains were 46,XY, -18, + i(18q) and another with multiple chromosome aberrations as described in Sezary T-cell leukemia. Phenotyping with monoclonal antibodies and T-cell receptor analysis indicates that the latter cell strain represents a minority of T-cells in the plaque. Due to its many chromosomal aberrations it probably represents the malignant cell, which may be a central cell in the immune stimulation taking place in the skin.
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PMID:Establishment of two continuous T-cell strains from a single plaque of a patient with mycosis fungoides. 158 90

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 reported recently that a novel immunomodulator, 7-thia-8-oxoguanosine (7T8OG)2 inhibited formation of pulmonary melanoma metastases (1), prevented against viral infection in mice (2) and potentiated the efficacy of a weakly immunogenic leukemia vaccine (3). Since certain tumor metastases and virus infected cells are targets to natural killer cells (NK cells), we now investigated whether 7T8OG is capable of activating NK cells in mice using NK cell sensitive YAC-1 and B16 and NK cell insensitive P815 targets. CBA/CaJ spleen cells incubated in vitro with 7T8OG at concentrations ranging from 0.005 to 0.5 mM responded with increased NK cell activity (32-62%) compared to controls (4-8%) to YAC-1 targets. Similar levels of augmentation in NK cell activity were observed when 40-168 mg/kg of 7T8OG was administered in vivo. In addition to the spleen, 7T8OG activated NK cells in the bone marrow (BM), the lungs, the liver, and in peritoneal exudate cells (PE). Although 7T8OG elicited activation of NK cells was observed as early as three hours after treatment, the maximal activity was observed after 24 h in the spleen; 12 h in the BM; 48 h in the lungs, and 72 h in PE. Administration of the drug by s.c., i.v., and i.p. routes all induced activation of NK cells in spleen, BM and PE. 7T8OG was found to activate NK cells in seven inbred and an outbred mouse strain, suggesting that the induced cytotoxicity against allogeneic and syngeneic tumor cells is not strain specific as well as independent of MHC restriction. C3H/He, CBA/CaJ and BDF/1 displayed higher levels of increased NK cell activity, whereas AKR mice were low responders. Low concentrations of IL-2 (0.25-5 U/ml) that induce little or no NK cell activity, when used in combination with 7T8OG, elicited significant enhancement of NK cell cytotoxicity. In contrast, IFN and 7T8OG showed no such synergism.
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PMID:Immunomodulatory activity of a novel nucleoside, 7-thia-8-oxoguanosine: I. Activation of natural killer cells in mice. 159 50


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