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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Regulatory effects on myelopoiesis and myelogenous leukaemia cell proliferation mediated by a human T cell clone (TCC) carrying a gamma/delta receptor have been studied. MHC-unrestricted cytotoxicity could be induced in this clone by culture with IL-2 but not IL-4. Increasing concentrations of IL-2 resulted in increased lysis of natural killer (NK)-susceptible target cells but lysis of NK-resistant targets could not be induced. Moreover, cytotoxicity on fresh chronic myeloid leukaemia cells was not measurable even after culture with 1000 U/ml IL-2. However, NK-resistant targets could be lysed when anti-receptor antibodies (OKT3 or TCR-delta 1) were added to the assay. Clone 290-2 cells secreted lymphokines potentially inhibitory for myelopoiesis (TNF-alpha, IFN-gamma), and their supernatants could inhibit optimally stimulated granulocyte/macrophage colony formation by normal bone marrow. Moreover, 290-2 cells prevented the consistently observed IL-3-stimulated enhancement of proliferation of CML cells, although even IL-3-pretreated leukaemic cells were still resistant to lysis by this clone. Thus, cells of this type, even when not directly cytolytic, could have a role in the regulation of myeloid cell growth.
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PMID:Regulation of normal myelopoiesis and chronic myelogenous leukaemia cell proliferation through a non-cytotoxic mechanism by a gamma/delta T cell clone. 253 Jan 64

An immunoglobulin M (IgM)-positive cell line, Ms 28, apparently spontaneously transformed by Epstein-Barr virus (EBV) was established from peripheral blood cells of a patient with immature myeloblastic leukemia. It has been characterized according to phenotype, cytochemistry, and membrane antigen pattern. The cell line expresses lymphoid markers like CD 19, CD 22, and CD 30 and synthesizes and secretes IgM. Monocyte markers CD 11c, CD 14, and CD 15 are absent. Neither interleukin-1 (IL-1), nor tumor necrosis factor (TNF-alpha) are produced. But Ms 28 cells show strong phagocytic activity and engulf Latex particles and sheep RBCs (SRBCs) that need not to be opsonized. The phagocytic activity can be inhibited by chloroquine. Both phagocytosis and EBV nuclear-antigen (EBNA) expression can be observed in one and the same cell. Ms 28 cells might be useful to study immunologic activities like antigen processing and presentation.
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PMID:Establishment and characterization of an Epstein-Barr virus transformed cell line with strong phagocytic activity. 254 24

We have cloned a previously undescribed adhesion molecule, VCAM-1, which is induced by cytokines on human endothelial cells and binds lymphocytes. Using a novel method requiring neither monoclonal antibodies nor purified protein, VCAM-1-expressing clones were selected by adhesion to human lymphoid cell lines. VCAM-1 mRNA is present in endothelial cells at 2 hr after treatment with IL-1 or TNF-alpha and is maintained for at least 72 hr; leukocyte binding activity parallels mRNA induction. Cells transfected with VCAM-1 bind the human leukemia lines Jurkat, Ramos, Raji, HL60, and THP1, but not peripheral blood neutrophils. VCAM-1, which belongs to the immunoglobulin gene super-family, may be central to recruitment of mononuclear leukocytes into inflammatory sites in vivo.
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PMID:Direct expression cloning of vascular cell adhesion molecule 1, a cytokine-induced endothelial protein that binds to lymphocytes. 268 98

In this paper we communicate that cells of a selected B-CLL clone (I83), after 2 days of Staphylococcus aureus Cowan strain 1 (SAC) activation, respond to recombinant IL-2 (rIL-2) and a B cell stimulatory factor (BSF-MP6) and act in strong synergism with induction of simultaneous high-rate proliferation and differentiation. None of the factors alone or other lymphokines (IFN-gamma, TNF-alpha, 12 kDa BCGF, IL-1, IL-4, IL-5, IL-6) induced significant DNA synthesis in SAC-activated cells. However, low levels of IgM were produced by cells stimulated by SAC + rIL-2. The SAC activation was followed by an increase in IL-2 receptor (IL-2R; CD25) expression, and the proliferation induced by BSF-MP6 + rIL-2 could be blocked in a dose-dependent manner by alpha-CD25 antibody. Furthermore, flow cytometric cell cycle studies showed that SAC and BSF-MP6 + rIL-2 stimulated cells underwent a complete transition through the cell cycle to become arrested in G1. The induced proliferation by BSF-MP6 + rIL-2 was dependent on serum but independent of the 2.8% of CD4, CD8, CD14, and CD16 positive cells contaminating the I83 cell population. Previously, we reported that I83 cells activated by 12-O-tetradecanoylphorbol-13-acetate (TPA) were induced to differentiation only but that the addition of BSF-MP6 induced DNA synthesis concomitantly with the differentiation. This paper demonstrates that physiological stimuli can induce both high-rate proliferation and differentiation in a B-CLL clone in vitro. It also suggests that the low proliferation and the differentiation block in vivo, characteristic of most B-CLLs, may reflect a subnormal response of B-CLL cells to growth and differentiation factors, or a dysfunction in the factor production by the patients' T cells.
Leukemia 1989 Aug
PMID:Interleukin-2 and a T cell hybridoma (MP6) derived B cell-stimulatory factor act synergistically to induce proliferation and differentiation of human B-chronic lymphocytic leukemia cells. 217 41

Autonomous in vitro growth of myeloid leukemic colony-forming cells may in part result from autocrine production of colony-stimulating factors (CSF). Some acute myeloid leukemia (AML) samples, however, fail to synthesize CSF despite growing autonomously in agar, and are therefore believed to bypass CSF requirements. Cytokines such as IL-6, tumor necrosis factor (TNF)-alpha, and IL-1, products of cells of the myeloid lineage, are known to be involved in growth control of myeloid progenitor cells. Since these molecules may also contribute to autocrine and paracrine growth regulation of myeloid leukemias, we screened a series of AML for cytokine production. In addition, possible roles of IL-6, TNF-alpha, and IL-1 in growth control of AML were investigated in vitro. We show that a substantial proportion of AML cells produce IL-6, TNF-alpha, and IL-1-beta and use these mediators to stimulate their growth by disparate mechanisms: IL-6 acts as a costimulator to enhance CSF-induced clonogenicity of AML blasts. TNF-alpha induces CSF production by endothelial cells and may therefore provide a paracrine loop to support leukemia growth.
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PMID:Participation of the cytokines interleukin 6, tumor necrosis factor-alpha, and interleukin 1-beta secreted by acute myelogenous leukemia blasts in autocrine and paracrine leukemia growth control. 1456 12

Bacterial products are potent stimulators of TNF and IL-1 release, however, the factors that regulate cytokine secretion in the absence of bacterial products are not well defined. P48 is a cytokine recently identified in the supernatant of the human null cell leukemia cell line Reh, which induces differentiation and cytolytic activity in HL-60 cells. P48 has been purified to homogeneity and is distinct from TNF-alpha TNF-beta, IFN-gamma, IL-6, and macrophage CSF. In the present study we examined the ability of P48 to stimulate cytokine release by human peripheral blood monocytes. P48 stimulated the secretion of TNF and IL-1 in a dose-dependent manner. Priming the monocytes with IFN-gamma enhanced P48-induced cytokine release but was not a requirement for secretion. Cytokine secretion was in response to P48 and was not caused by endotoxin contamination. The cytokine-inducing activity of P48 was extremely sensitive to heat treatment but could not be eliminated by using polymyxin B. Polyclonal antisera to P48 completely blocked the cytokine-inducing activity. P48 may be an important new member of the cytokine network involved in the regulation of cytokine secretion by monocytes.
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PMID:P48 induces tumor necrosis factor and IL-1 secretion by human monocytes. 280 97

The IL-2R alpha enhancer contains an 11 bp sequence that resembles kappa B, a regulatory element associated with several genes, including Ig kappa-L chain and human immunodeficiency virus. Although nuclear factor of the kappa-enhancer in B cells (NF-kappa B) binding is activated by PMA, TNF-alpha, and IL-1, activation of the IL-2R alpha enhancer does not consistently correlate with NF-kappa B induction. In this report, we show that TNF-alpha activates NF-kappa B and the human immunodeficiency virus enhancer in the Jurkat T leukemia but does not stimulate the IL-2R alpha enhancer. In contrast, this cytokine, and IL-1, increased IL-2R alpha gene expression in YT-1 cells. Comparing YT-1 and Jurkat T leukemias, we find that the IL-2R kappa B site is required for TNF-alpha and IL-1 stimulation in YT-1 cells, but that plasmids containing this site linked to a heterologous promoter do not respond to these cytokines. These data suggest that upstream regulatory elements in addition to IL-2R kappa B are needed to mediate this cytokine effect. TNF-alpha also synergized with PMA and other cytokines in the stimulation of the IL-2R alpha enhancer in YT-1. Because these effects are not observed in Jurkat cells, the function of the IL-2R kappa B site is cell-specific and likely mediated by different associated transcription factors present in each cell type.
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PMID:Regulation of the IL-2 receptor alpha-gene. Interaction of a kappa B binding protein with cell-specific transcription factors. 280 16

We evaluated cytotoxic factor released from rat basophilic leukemia cells (RBL) sensitized with anti-ovalbumin (OVA) mouse serum after incubation with OVA. The cytotoxic activity of this factor was completely blocked by anti-mouse tumor necrosis factor-alpha (mTNF-alpha) specific antibody. Therefore, we concluded that by triggering the IgE receptor, RBL could produce and release TNF-alpha.
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PMID:The production of tumor necrosis factor-alpha by rat basophilic leukemia cells with triggering IgE receptor. 297 97

We tested the antiproliferative effect induced by the natural human tumor necrosis factors alpha and beta (nHuTNF-alpha, -beta) or a combination of these in the clonogenic assay. The antiproliferative effects were evaluated by examining the inhibition of clonogenic growth of RPMI-4788 cells, which had been established from a human colon cancer. TNF-alpha and -beta were natural human types produced by a B cell leukemia line (BALL-1 cells) and were both over 99% pure. The antiproliferative effect in combination of nHuTNF-alpha and -beta was analysed by using the median effect plot and the combination index. The results indicate a synergism between two factors.
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PMID:Synergistic effect of natural human tumor necrosis factors alpha and beta in the clonogenic assay. 322 48

Increasing evidence is revealing that cytokines, under the control of steroid hormones, are important in regulating fetal-maternal interactions during pregnancy. Mice carrying mutated genes coding for these factors or their receptors, have been instrumental in clarifying the in vivo roles of these factors in reproduction. Lack of many of the cytokines expressed in the male and female reproductive tracts, such as TNF-alpha, Inf-gamma, the majority of the interleukins and the transforming growth factors TGF-alpha and beta do not result in any gross impairment in reproductive efficiency. However, some cytokines do have a critical role, in particular Leukemia Inhibitory Factor (LIF), Colony stimulating Factor-1 (CSF-1), Epidermal Growth Factor (EGF) and possibly interleukin-1 (IL-1). The recent advances relating to the reproductive roles of these factors up to the time of embryo implantation will be discussed.
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PMID:[Regulation by maternally derived cytokines of pre-implantation development and uterine receptiveness]. 749 29


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