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Query: UNIPROT:P04141 (
granulocyte-macrophage colony-stimulating factor
)
6,790
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Human natural killer cells (NK) respond to interleukin-2 (IL-2) with augmented cytolytic activity, cytokine secretion and cell proliferation. Here we show that IL-2 protects NK cells from death by apoptosis (programmed cell death; PCD). Highly purified NK cells (CD3- CD56+) were isolated from peripheral blood lymphocytes (PBL) of either control donors or of an asymptomatic donor with 60% NK cells. Glucocorticosteroids (GCS) induced PCD in NK cells, as shown by nuclear condensation and DNA fragmentation. IL-2 completely prevented GCS-induced PCD in a dose-dependent manner without overcoming GCS-induced inhibition of NK cell proliferation. The IL-2 protective effect was mediated through the p75 beta chain of the IL-2R, as neutralizing monoclonal antibody (mAb) to the p75 beta chain but not to the p55 alpha chain completely abolished the IL-2 anti-apoptotic activity. In addition to IL-2, the cytokines IL-7 and IL-12 have been reported to regulate NK cell functions. Our present data showed that IL-7 but not IL-12 rescued NK cells from apoptosis, but to a lesser extent than IL-2. Although IL-4 had a marginal protective effect, IL-1, IL-3, IL-6, IL-8, interferon-gamma (IFN-gamma) and IFN-alpha, tumour necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta) and
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) displayed no significant activity. Finally, we report that IL-2 and IL-7 enhanced
bcl-2
expression in NK cells, suggesting the existence of a
bcl-2
-dependent survival pathway. In addition to regulating various functions, it is concluded that IL-2 and IL-7 have the ability to prevent PCD in NK cells.
...
PMID:IL-2 and IL-7 but not IL-12 protect natural killer cells from death by apoptosis and up-regulate bcl-2 expression. 764 25
Treatment of M1 myeloid leukemic cells with interleukin 6 (IL-6) or dexamethasone (DEX), both of which induce differentiation in these cells, down-regulated expression of the apoptosis-suppressing gene
bcl-2
and the apoptosis-promoting gene bax but up-regulated expression of the apoptosis-suppressing gene bcl-XL. There was a higher expression of bcl-XL in cells treated with DEX or DEX plus IL-6 compared to cells treated with IL-6 alone. The alternatively spliced bcl-X gene, bcl-Xs, which interferes with the action of
bcl-2
, was not expressed. Treatment with IL-6 increased the susceptibility of these cells to induction of apoptosis by Adriamycin or cycloheximide, but treatment with DEX or with IL-6 and DEX did not. Withdrawal of DEX after up-regulation of bcl-XL resulted in a decrease in bcl-XL expression and a concomitant increase in cell susceptibility to induction of apoptosis. Another myeloid leukemia that shows barely detectable expression of
bcl-2
also showed up-regulated expression of bcl-XL but no change in bax after induction of differentiation with
granulocyte-macrophage colony-stimulating factor
, and this reduced cell susceptibility to induction of apoptosis by Adriamycin or cycloheximide. The results indicate that the related apoptosis-regulating genes
bcl-2
, bcl-XL, and bax are differently regulated and that up-regulation of bcl-XL expression may compensate for down-regulation of
bcl-2
in the balance between genes that control apoptosis.
...
PMID:Regulation of bcl-2, bcl-XL and bax in the control of apoptosis by hematopoietic cytokines and dexamethasone. 766 18
When interleukin-3 (IL-3) dependent DA-1 cells were cultured on hemopoietic supportive stromal cells (MS-5), DA-1 cells survived and proliferated in the absence of detectable IL-3. Although IL-3 was not produced by the MS-5 cells, their production of
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) was increased when they were co-cultured with DA-1 cells. This suggests that DA-1 cells transmit signals to stromal cells that enhance growth factor(s) production. Expression of
bcl-2
by DA-1 cells was induced when they were co-cultured with MS-5 cells, suggesting that DA-1 cells express
bcl-2
strongly in response to a signal produced by MS-5 cells. These data indicate the existence of a two-way interaction between DA-1 cells and hemopoietic supportive stromal cells.
...
PMID:Induction of bcl-2 gene expression by intercellular information from hemopoietic supportive stromal cells to DA-1 cells. 796 21
Previous studies have shown that the
bcl-2
gene encodes a mitochondrial protein which can inhibit the onset of apoptosis induced by withdrawal of trophic factors or by antitumour drugs. In some malignant cells
bcl-2
expression has been demonstrated to be regulated by specific trophic factors which act to suppress apoptosis. Here we have investigated the effect of exogenous and autocrine
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) on both
bcl-2
expression and apoptosis in acute myeloid leukaemia (AML) cells. Blasts from 31 patients with AML were studied, this included 21 patients whose cells exhibited variable degrees of autonomous growth in culture and ten patients with non-autonomous growth. Blasts with autonomous growth expressed significantly higher levels of
bcl-2
protein, the intensity of fluorescence expressed as soluble fluorochrome per cell was 40.9 +/- 3.6 x 10(3) (mean +/- SD); this compared with an intensity of
bcl-2
expression of 19.3 +/- 2.4 x 10(3) for blasts with non-autocrine growth (p < 0.0001 by Mann-Whitney analysis). Blasts with non-autocrine growth rapidly lost viability following 48 h of culture due to the onset of apoptosis. In these cells apoptosis was suppressed by the addition of
GM-CSF
and
bcl-2
protein expression was found to be significantly upregulated. In contrast blasts from patients with autonomous growth and autocrine
GM-CSF
production failed to show any features of apoptosis in culture. In these cells
bcl-2
expression was significantly downregulated following neutralization of autocrine
GM-CSF
by antibodies. We conclude that
bcl-2
expression in AML cells is regulated by
GM-CSF
, and suggest that the previously demonstrated negative prognostic effect of autocrine growth as a determinant of treatment outcome in AML is in part due to the effect of autocrine
GM-CSF
in upregulating
bcl-2
expression.
...
PMID:Regulation of Bcl-2 expression and apoptosis in acute myeloblastic leukaemia cells by granulocyte-macrophage colony-stimulating factor. 818 35
Granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) stimulates hemopoietic cell proliferation, differentiation, and functional activation by inducing the expression of specific genes. As part of an investigation of the regulation of gene expression by
GM-CSF
, we have previously identified a novel murine
GM-CSF
-inducible gene, A1. In this report, we present the complete nucleotide sequence of the A1 mRNA as well as a portion of the 5' flanking region, and describe the expression pattern of the gene. The results demonstrate that A1 is a hemopoietic tissue-specific gene that is expressed in several hemopoietic cell lineages, including T-helper lymphocytes, macrophages, and neutrophils. In murine bone marrow-derived macrophages, A1 gene expression is rapidly and transiently induced by
GM-CSF
, and the induction was independent of de novo protein synthesis. In addition to
GM-CSF
, a transient induction of A1 mRNA accumulation was observed in response to LPS in macrophages. This induction is not mediated by IL-1 alpha or IL-6, neither of which stimulate A1. In the myeloid precursor cell line, 32D cl3, A1 gene expression is stably induced during granulocyte colony-stimulating factor-stimulated myeloid cell differentiation. The A1 message encodes a predicted polypeptide with an M(r) of 20,024 and no signal peptide. The peptide sequence contains a region of 80 amino acids that shows similarity to
bcl-2
and to the recently described
bcl-2
-related gene, MCL1. These data demonstrate that A1 is a novel early-response gene whose expression is associated with a variety of stimuli and occurs in several hemopoietic cell types.
...
PMID:Characterization of A1, a novel hemopoietic-specific early-response gene with sequence similarity to bcl-2. 834 91
A strictly stroma-dependent hematopoietic clone, Myl-D-7, with lympho-myeloid potential has been isolated. A subset of cells expresses myeloid-macrophage (Mac-1 and Gr-1), erythroid (TER119), and lymphoid (Thy-1 and B220) lineage markers. Spontaneous differentiation to the myeloid-macrophage, erythroid, or lymphoid pathway can be seen by morphologic criteria, detection of beta major globin synthesis, or expression of the early lymphoid specific transcription factor, Ikaros. By sorting lineage marker (Mac-1, Gr-1, B220, and TER119)-negative (LIN-) cells, we showed that the LIN- population actively self-renews on top of MS-5 stromal cells, and differentiates to LIN+ cells. Removal of stroma induces apoptosis and none of the growth factors tested can prevent apoptosis.
Granulocyte-macrophage colony-stimulating factor
accelerates the differentiation towards the myeloid-macrophage lineage. Using this clone, we show that (1) contact with stroma induces expression of
bcl-2
, (2) stromal cells derived from SI/SI homozygous fetuses can support long-term growth, and (3) conditioned media of specific stromal cells contains an activity that supports proliferation and self-renewal of the clone. Myl-D-7 can thus be used as an indicator cell for unknown factors that may provide stromal cell support.
...
PMID:A novel hematopoietic multilineage clone, Myl-D-7, is stromal cell-dependent and supported by an alternative mechanism(s) independent of stem cell factor/c-kit interaction. 860 37
The cell-surface expression and the functional status of the CD95/Fas antigen on primitive hematopoietic progenitors (PHPs) freshly isolated from human fetal liver (FL) were studied. PHPs were phenotypically defined as CD34++ CD38 -/+ cells. The most immature subfractions of PHPs, CD34++CD38- and CD34+2CD38+ FL cells, expressed CD95, whereas the more mature CD34++CD38++ and CD34+CD38++2 FL cells displayed low CD95 expression. Combinations of cytokines, such as kit ligand (KL) + interleukin-3 or KL +
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) upregulated the expression of CD95 on PHPs upon in vitro culture. Tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) further increased the CD95 expression induced by KL+GM-CSF. The hematopoietic potential of sorted CD34++lineage (lin)- CD95+ versus CD34++ lin-CD95-FL cells was compared by colony-forming unit-culture (CFU-C) assays performed in serum-deprived medium. Lin+ cells were composed of erythrocytes, monocytes, T cells, B cells, and natural killer cells. Our results indicated that both CD95- and CD95+ subsets contained pluripotent progenitors, generating myeloid and erythroid progenitors. The functional status of CD95 and the effects of TNF-alpha and IFN-gamma, cytokines known to induce CD95-mediated apoptosis, were analyzed by incubation of PHPs in the presence of anti-CD95 monoclonal antibodies (MoAbs). The effect of anti-CD95 MoAbs was measured by viable cell counting, flow cytometry, and CFU-C assays. A decrease of CFU-C numbers was observed in the presence of anti-CD95 MoAbs and TNF-alpha and/or IFN-gamma. However, whereas growth factor deprivation induced apoptosis of PHPs, cross-linking of CD95 did not lead to apoptosis of PHPs measured by flow cytometry and viable cell counting. The correlation of increased intracytoplasmic levels of
bcl-2
with high levels of cell-surface CD34 and the presence of CD95 on fresh FL cells suggests that
bcl-2
may be involved in protecting against CD95-mediated apoptosis of FL PHPs.
...
PMID:Expression of Fas/CD95 and Bcl-2 by primitive hematopoietic progenitors freshly isolated from human fetal liver. 882 20
Nerve growth factor (NGF) promotes mast cell survival in vitro (Horigome, K., Bullock, E. D., and Johnson, E. M., Jr. (1994) J. Biol. Chem. 269, 2695-2702). NGF survival promotion is cell density-dependent, and conditioned medium experiments have shown that NGF increases the production of an autocrine mast cell survival activity. Cytokines are potential candidates for autocrine survival factors. In rat peritoneal mast cells (RPMC), NGF caused an increase in the messenger RNAs for interleukin (IL)-3, IL-4, IL-10, tumor necrosis factor-alpha, and
granulocyte-macrophage colony-stimulating factor
. This induction was NGF dose-dependent, was blocked by NGF-neutralizing antibodies, and was not observed in the non-mast peritoneal cell population. The immunosuppressive agent, cyclosporin A, blocked both cytokine induction and NGF-activated survival promotion but not survival promotion activated by IL-3 or stem cell factor, suggesting that NGF enhanced RPMC survival by increasing cytokine production. We also examine the effects of NGF on the expression levels of some members of the
bcl-2
family and the interleukin-1beta-converting enzyme-like cysteine protease families. NGF markedly increased
bcl-2
expression but had little or no effect on the other genes studied. The induction of
bcl-2
mRNA by NGF was not blocked by cyclosporin A. These data suggest that induced cytokine gene expression but not increased expression of
bcl-2
mediates NGF-survival promotion in RPMC.
...
PMID:Nerve growth factor induces the expression of certain cytokine genes and bcl-2 in mast cells. Potential role in survival promotion. 891 Mar 34
Infectious microorganisms can differently induce or inhibit apoptosis of immunocompetent effector and host cells. In this study we examined the influence of an infection by Candida albicans (C. albicans) on programmed cell death of monocytic U937 cells and human monocytes. Basal and tumor necrosis factor alpha (TNF-alpha)-induced DNA fragmentation of U937 cells was significantly inhibited by an infection with C. albicans. Enhanced apoptosis of U937 cells, induced by TNF-alpha, caused a diminished candidacidal activity of the effector cells, whereas inhibition of apoptosis by
granulocyte-macrophage colony-stimulating factor
(
GM-CSF
) was paralleled by an intensified host defense. Pretreatment of U937 cells or monocytes with the cyclooxygenase blocker indomethacin completely abolished the reduction of DNA fragmentation induced by the yeast. Studying the underlying mechanisms we found that C. albicans induced formation of prostaglandin E2 (PGE2) by U937. Exogenous administration of PGE2 down-regulated apoptosis of U937 or human monocytes to a similar extent as did fungal infection. Activation of protein kinase A by the cAMP analogue 8-bromo-cAMP inhibited U937 apoptosis, as did PGE2. On the other hand, rp-cAMP, a blocker of the cAMP-dependent signal transduction, restored and elevated DNA fragmentation levels down-regulated by C. albicans. U937 cells expressed the
bcl-2
protein but the infection with fungi or PGE2 treatment did not increase proto-oncogene expression. Monocytic effector cells may therefore strengthen the defense against C. albicans by an autocrine feedback regulation via a PGE2-dependent, cAMP-transduced inhibition of apoptosis.
...
PMID:Infection by Candida albicans inhibits apoptosis of human monocytes and monocytic U937 cells. 897 76
Granulocyte-macrophage colony-stimulating factor
(
GM-CSF
), interleukin (IL)-3, and IL-5 stimulate DNA synthesis and proliferation and inhibit apoptosis in hematopoietic cells. Multiple signal pathways are activated by binding of these ligands to their receptors, which share a common beta subunit. Janus protein kinase 2 (Jak2) binds to the membrane proximal domain of the beta chain and is phosphorylated on receptor ligation. To explore the role of Jak2 in the regulation of specific signal transduction pathways, we constructed fusion proteins with a CD16 external domain, a CD7 transmembrane region, and a Jak2 cytoplasmic domain. This cytoplasmic domain consisted either of wild type Jak2 (CD16/Jak2-W) or Jak2 mutations with deletions of (a) the amino terminus (CD16/Jak2-N), (b) kinase-like domain (CD16/Jak2-B), (c) kinase domain (CD16/Jak2-C), or (d) amino-terminal and kinase-like domains, leaving the kinase domain (CD16/Jak-K) intact. In contrast to the CD16/Jak2-W fusion protein, which requires cross-linking for activation, CD16/Jak2-N, CD16/Jak2-B, and CD16/Jak2-K were constitutively phosphorylated, and they stimulated Shc phosphorylation and increased binding of STAT to DNA in Ba/F3 cells. Cell lines derived from IL-3-dependent Ba/F3 cells stably transfected with CD16/Jak2-W, CD16/Jak2-N, or CD16/Jak2-B mammalian expression vectors died at a rate similar to that of the parental cells on IL-3 deprivation. In contrast, CD16/Jak2-K cell lines exhibited increased expression of
bcl-2
and pim-1 mRNA and maintained their viability when compared with control cell lines. Thus, activation of tyrosine phosphorylation by creating a CD16/Jak2-K fusion is sufficient to activate pathways that prevent cell death.
...
PMID:The kinase domain of Jak2 mediates induction of bcl-2 and delays cell death in hematopoietic cells. 913 79
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