Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
 6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bacterial superantigens are the most potent known activators of human T lymphocytes. To engineer superantigens for immunotherapy of human colon carcinoma, the superantigen, staphylococcal enterotoxin A (SEA) was genetically fused to the Fab region of the colon carcinoma-reactive monoclonal antibody C242. In the present study the effector mechanisms involved in the anti-tumor response to C242 Fab-SEA were characterized. Immunohistochemistry and computer-aided image analysis were used in studies of cryopreserved tumor tissue to evaluate the phenotype of infiltrating cells and their cytokine profiles in response to therapy. Human T cells and monocytes were recruited to the tumor area and penetrated the entire tumor mass within hours after injection of C242 Fab-SEA. The production of cytokines at the single-cell level was found to be dominated by tumor necrosis factor (TNF)-alpha, interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12, interferon (IFN)-gamma, granulocyte-macrophage colony-stimulating factor, and transforming growth factor-beta, whereas IL-1-alpha, IL-1ra, IL-1 beta, TNF-beta, IL-3, IL-6, and IL-8 were undetectable. Most of the TNF-alpha, IL-2, IL-12, and IFN-gamma were made by the infiltrating human leukocytes, while the colon carcinoma cells were induced to produce IL-4, IL-10, and TNF-alpha. Up-regulation of IFN-gamma receptors and TNF R p60 receptors was found, while the TNF R p80 receptor was absent. The cytokine production, T cell infiltration, and CD95 Fas receptor expression concomitantly occurred to induce programmed cell death in the tumor cells. This was followed by a strong reduction of the tumor mass that was seen within 24 h after C242 Fab-SEA infusion. These findings demonstrate that antibody-superantigen proteins efficiently recruit tumor-infiltrating lymphocytes actively producing a variety of cytokines likely to be essential for the therapeutic effects observed in the model. Although the humanized SCID model has obvious limitations in its predictive value for treatment of human cancer, we believe that these results encourage clinical evaluation of antibody-targeted superantigens.
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PMID:Antibody-targeted superantigen therapy induces tumor-infiltrating lymphocytes, excessive cytokine production, and apoptosis in human colon carcinoma. 856 49

Thrombopoietin (TPO) is a recently characterized growth and differentiation factor for megakaryocytes and platelets exerting its effects via the receptor MPL. We examined the expression of MPR on the cell surface of a panel of 43 myelomonocytic, erythroid and megakaryocytic leukemia cell lines and 21 primary acute myeloid leukemia (AML) cases by flow cytometry. With few exceptions MPL was found on all 32 erythroid/megakaryocytic cell lines and on all 11 growth factor-dependent myelomonocytic cell lines, albeit at variable percentages and intensities per cell population (with a 10% cut-off level for positivity still 30/43 cell lines scored as MPL positive). The majority of the primary AML samples (including all seven M6/M7 cases) expressed the MPL protein regardless of the morphological and immunological subtype (13/21 cases had >10% MPL-positive cells). Recombinant TPO overexpressed in hamster cells induced a mitogenic response in seven cell lines (one growth factor-independent and six factor-dependent lines) and in 3/21 AML specimens (two AML M2, one AML M7) as measured by 3H-thymidine incorporation. Expression of MPL clearly did not correlate with response to TPO. For further detailed studies of the interaction of TPO with other cytokines we used the AML M7-derived M-07e cells as an informative indicator cell line for which both murine and human TPO acted as a very potent mitogen in a dose-dependent fashion (3- to 11-fold proliferation increase relative to medium alone). This growth factor-dependent cell line which is normally cultured in conditioned medium containing several cytokines could be grown in long-term culture supplemented only with TPO. Co-incubation of M-07e with various cytokines and TPO showed additive proliferative effects for interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) and synergistic responses for stem cell factor (SCF), interferon (IFN)-alpha, and to a lesser extent for IFN-gamma and tumor necrosis factor (TNF)-alpha. Erythropoietin (EPO), IL-1, IL-6, IL-11 and leukemia inhibitory factor (LIF), know as megakaryocytic maturation-inducing molecules, were not substantially effective, neither singly nor in combination with TPO, with regard to cell growth. Transforming growth factor (TGF)-beta1 antagonized the inductive effect of TPO on M-07e cell growth. Addition of TPO to cultures of megakaryocytic cell lines failed to significantly alter the ploidy distribution and the differentiation marker immunoprofile of the cells indicating a lack of maturation-inducing effects in this model system. In summary, TPO represents an efficient in vitro potentiator of megakaryocytic leukemia proliferation of at least some primary cases or cell lines. While TPO seems to be the major physiological regulator of megakaryocytopoiesis, the present data suggest also some proliferative effects on certain leukemia cells, apparently on non-megakaryocytic leukemia cells as well, thus assigning to TPO a possible pathobiological role in leukemogenesis which would be of clinical relevance. Our data show that the response to TPO is not restricted to cells committed to the megakaryocytic differentiation pathway as we could demonstrate TPO-responsive megakaryocytic and non-megakaryocytic cell lines; thus, these cell lines represent powerful tools in such analyses. Consequently, this new cytokine needs to be properly examined so we can get a clear understanding of the clinical possibilities and dangers.
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PMID:Expression of the receptor MPL and proliferative effects of its ligand thrombopoietin on human leukemia cells. 863 39

A large body of clinical experience on the adverse consequences of cytokine administration has accumulated since the last decade. Side-effects reported after the therapeutic use of cytokines has provided evidence that activation of the immune response may sometimes have deleterious consequences. Several effects appeared as a direct consequence of the immune activation induced by cytokines, e.g. flu-like reactions, vascular leak syndrome. Cytokine-induced exacerbation of underlying diseases or immune dysregulation were other complications of growing concern. Interferon-alpha (IFN-alpha) treatment has now been clearly linked with the exacerbation or the occurrence of several types of autoantibodies or autoimmune diseases (thyroiditis, systemic lupus erythematosus, hematologic disorders, insulin-dependent diabetes mellitus) or diseases involving altered cell-mediated immune functions (inflammatory dermatologic diseases, nephritis, pneumonitis, colitis). By contrast immunological side-effects of IFN-beta and IFN-gamma have been seldom reported. However, the extent of clinical experience with both of these cytokines is still very limited. Interleukin-2 (IL-2) has also been implicated in various conditions that may involve immunopathological processes (thyroid disorders, rheumatoid arthritis, dermatological diseases, interstitial nephritis). Growth factors have been more specifically linked with the development or the exacerbation of dermatological inflammatory diseases through neutrophils, monocytes/macrophages or eosinophils activation (e.g. cutaneous vasculitis and generalized cutaneous eruption, Sweet's syndrome, bullous eruption, psoriasis). Exacerbation of autoimmune thyroiditis was described with granulocyte-macrophage colony-stimulating factor (GM-CSF) only. The immunogenicity of cytokines is also of great relevance and the occurrence of antibodies binding IFN-alpha and IFN-beta, IL2 and GM-CSF have been reported. While the clinical significance of non-neutralizing antibodies is not clearly established, an absence of response or reversal of clinical efficacy has been described in patients developing neutralizing antibodies. Finally, several isolated reports have recently suggested that IFN-alpha treatment may be associated with several immunosuppressive effects while IL-2 is clinically associated with an increased incidence of infectious complications.
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PMID:Immune-mediated side-effects of cytokines in humans. 863 83

We have previously described a two-step methylcellulose culture system in which individual primitive progenitors from 5-fluorouracil (5-FU)-treated mice were shown to have both myeloid and B lymphoid differentiation capacity. Highly enriched Lin-Sca+FU2d BM cells were cultured in methylcellulose in the presence of Steel factor (SF), interleukin-7 (IL-7), and pokeweed mitogen stimulated spleen cell conditioned medium (PWM-SCM). Primary mixed myeloid colonies were replated after 8-11 days into secondary cultures containing SF and IL-7, which supported the generation of B220+sIgM- pre-B cell colonies. A number of growth factors, including IL-6, IL-11, granulocyte colony-stimulating factor (G-CSF), and IL-12 were shown to be capable of substituting for PWM-SCM to support the B lymphoid potential of primary colonies. B lymphoid potential was not supported, however, in SF + IL-3 or in SF + IL-3 plus any single growth factor (IL-1 to -12, granulocyte-macrophage colony-stimulating factor [GM-CSF], G-CSF, erythropoietin [Epo], leukemia inhibitory factor [LIF], tumor necrosis factor-alpha [TNF-alpha], transforming growth factor-beta [TGF-beta], gamma interferon [IFN-gamma], or insulin-like growth factor-1 [IGF-1]), but was supported in SF + IL-3 + 5% PWM-SCM. Experiments were designed to identify the factor or factors in PWM-SCM that reverse the inhibitory effects of IL-3 on B lymphoid potential. By substituting various cytokine combinations for PWM-SCM, we determined that combinations of IL-4 + IL-6 or IL-4 + IL-11, but not IL-4 alone, can substitute for PWM-SCM to reverse the inhibitory effect of IL-3 on B lymphoid potential. Neutralizing antibodies to IL-4 completely eliminated the activity in PWM-SCM, but antibodies to IL-6 only partially inhibited the activity. IL-11 was not detected in PWM-SCM, and the activity co-purified with IL-4, but not with IL-6. Thus, IL-4 plus IL-6, IL-11, or one or more unidentified growth factors in PWM-SCM can reverse the inhibitory effects of IL-3 on early B lymphocyte development in culture.
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PMID:Interleukin-4 (IL-4) in combination with IL-11 or IL-6 reverses the inhibitory effect of IL-3 on early B lymphocyte development. 864 28

A central factor in the pathogenesis of inflammatory and fibrotic lung disease (adult respiratory distress syndrome, sarcoidosis, idiopathic pulmonary fibrosis) is the locally elevated number of alveolar macrophages (AM). An elevation in the production rate of AM, chemoattraction and differentiation of monocytes, or a diminution in the death rate might be underlying mechanisms. The aim of the present study was to investigate the modulatory role of endotoxin and cytokines on the death rate of human AM. Lipopolysaccharide (LPS) treatment resulted in a 4-fold increase (7.6 to 30.2%) of AM death. AM death was apoptotic as assessed by in situ DNA end labeling (ISDE), transmission electron microscopy, DNA gel electrophoresis, fluorometry of fragmented DNA, and an ELISA specific for histone-associated DNA fragments. Among the different bacterial cell wall components tested, LPS was the only inducer of apoptosis in human AM. None of the tested cytokines (interleukin-1 beta [IL-1 beta], IL-4, IL-6, IL-10, tumor necrosis factor-alpha [TNF-alpha], transforming growth factor-beta 2 [TGF-beta 2], interferon-gamma [IFN-gamma], macrophage colony-stimulating factor [M-CSF], granulocyte colony-stimulating factor [G-CSF], and granulocyte-macrophage colony-stimulating factor [GM-CSF]) was capable of enhancing the spontaneous rate of apoptosis. However, LPS-induced apoptosis was significantly enhanced by the macrophage-activating cytokine IFN-gamma, and reduced by the macrophage-deactivating cytokines IL-4, IL-10, and TGF-beta.
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PMID:Apoptosis in human alveolar macrophages is induced by endotoxin and is modulated by cytokines. 867 23

It is well established that granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-1 and tumour necrosis factor-alpha (TNF-alpha) are involved in Langerhans' cell (LC) development and dendritic cell traffic. However, little is known about the pattern of cytokine receptors on human LC and their modulation during different stages of maturation. The expression of cytokine receptors was studied by flow cytometry on both freshly isolated LC (fLC) and 72-hr cultured LC (cLC). Epidermal cell suspensions enriched in LC were obtained after skin trypsinization and Ficoll-Hypaque gradient. LC were identified by their CD1a positivity. Although the majority of fLC were positive for the alpha chain of GM-CSF receptor (GM-CSFR), the beta chain of GM-CSFR was detected only on 15% of CD1a+ cells. fLC were also positive for IL-1 receptor (IL-1R) type 1, IL-1R type 2, 75,000 molecular weight TNF receptor (TNFR) and interferon-gamma receptor (IFN-gamma R). IL-6R and its transducing signal gp130 were present in a subset of fLC. Granulocyte colony-stimulating factor receptor (G-CSFR), macrophage colony-stimulating factor receptor (M-CSFR), the alpha and beta chain of IL-2R, IL-4R, IL-7R, IL-8R and 55,000 molecular weight TNFR were not detected on fLC. After culture, LC up-regulated the expression of both the alpha and beta chains of GM-CSFR, IL-1R type 2, alpha and beta chains of IL-2R, IL-6R and gp130. In contrast, IL-1R type 1 and 75,000 molecular weight TNFR were down-modulated and the expression of IFN-gamma R was not affected by culture. These results suggest that LC undergo changes in the cytokine receptor repertory during in vitro maturation.
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PMID:Flow cytometric analysis of cytokine receptors on human Langerhans' cells. Changes observed after short-term culture. 869 97

Human peripheral blood leukocytes (hPBL) are a rich source of natural leukocyte interferon (IFN-alpha) when treated with Sendai virus. Sendai virus treatment of hPBL will also result in significant production of several chemokines and cytokines such as macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, RANTES, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-8, in a time-dependent way. A significant amount of MCP-1 is constitutively produced in overnight culture of leukocytes. The most abundant cytokine is IFN-alpha, which is induced to its maximum level approximately 11-15 h after addition of Sendai virus. The amount of IFN-alpha induced at 15 h after Sendai virus treatment is more than 16-fold higher than those of MIP-1alpha, MIP-1beta, and RANTES. IFN-alpha is also induced more than 60-fold higher than TNF-alpha and IL-8. The amount of IL-6 induced is approximately 400-fold less than IFN-alpha. Limited amounts of other cytokines such as IL-1alpha, IL-1beta, macrophage colony-stimulating factor, TNF-beta, and IFN-gamma are also induced in Sendai virus-treated hPBL. No measurable amount of granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, leukemia inhibitory factor, IL-2, IL-3, IL-4, IL-5, IL-7, IL-10, IL-11, or IL-12 was induced in the supernatant of Sendai virus-treated hPBL.
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PMID:Cytokines induced by Sendai virus in human peripheral blood leukocytes. 869 16

Freshly excised human head and neck cancers (219 primary cancers; 64 metastatic lymph node cancers) were analyzed for the immune inhibitory mediators released from the cancer tissues and the immune infiltrate within the tumor. Significant levels of the immune inhibitory mediators transforming growth factor-beta (TGF-beta), prostaglandin E2 (PGE2) and interleukin-10 (IL-10) were released from these cancers. Also released was granulocyte-macrophage colony-stimulating factor (GM-CSF), whose secretion was associated with an intratumoral presence of CD34+ cells. We have previously shown that CD34+ cells within human head and neck cancers are immune inhibitory granulocyte-macrophage progenitor cells. The presence of TGF-beta, PGE2 and IL-10 was associated with a reduced content of CD8+ T-cells within the cancers. The CD4+ cell content appeared to be less affected by these immune inhibitory mediators. Instead, parameters indicative of CD4+ cell function (p55 IL-2 receptor expression, release of IL-2 and IFN-gamma) were diminished in cancers that released higher levels of TGF-beta, IL-10 and GM-CSF and had a higher CD34+ cell content. Furthermore, metastatic cancers released higher levels of the soluble immune inhibitory mediators and lower levels of IFN-gamma and IL-2 than did primary cancers, although CD34+ cells were similarly present in both primary and metastatic cancers. Our results show that human head and neck cancers have a multiplicity of non-mutually exclusive mechanisms of immune suppression that are most prominently associated with reduced CD8+ cell influx and reduced influx and altered function of intratumoral CD4+ cells.
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PMID:Mechanisms of immune suppression in patients with head and neck cancer: influence on the immune infiltrate of the cancer. 870 5

Murine neuroblastoma, neuro-2a, was transduced with the retroviral vector MFG-granulocyte-macrophage colony-stimulating factor (GM-CSF), to examine immune stimulation conferred by localized GM-CSF production. Expression of murine GM-CSF by neuro-2a (N-2a/GM) significantly reduced its tumorigenicity. Moreover, immunization of mice with irradiated N-2a/GM cells resulted in a significant protective effect against live tumor challenge 14 days later. Approximately 41% of mice immunized with irradiated N-2a/GM versus 0% of those vaccinated with irradiated parental tumor survived. Surviving mice were rechallenged after 50 days with wild-type neuro-2a or with the Sa1 syngeneic sarcoma to discern whether the generated immunity was durable and tumor specific. All mice survived wild-type neuro-2a challenge, whereas none survived inoculation with Sa1. Because both CD4+ and CD8+ T cells were necessary during priming to this MHC class Ilo, II-tumor, these data indicate that major histocompatibility complex (MHC) class I+, II+ antigen-presenting cells (APCs) were required for the T-cell antitumor response. Co-expression of GM-CSF and IFN-gamma, both of which have immunostimulatory activities on antigen-presenting cells, abrogated the tumorigenic potential of this tumor and increased immunogenicity over N-2a/IFN but not N-2a/GM. Vaccination of mice with preexisting retroperitoneal tumors with irradiated N-2a/GM and irradiated N-2a/IFN/GM improved survival. There was a trend for nonirradiated transduced cells to be more immunogenic than their irradiated counterparts. Immunohistochemistry of tissues from the vaccination site revealed a pronounced macrophage infiltration associated with nonirradiated N-2a/GM and N-2a/IFN/GM. These data suggest that vaccination involving nonirradiated neuroblastoma cells transduced with genes that stimulate APCs may be a useful approach in stimulating antitumor T-cell responses.
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PMID:Effective immunization against neuroblastoma using double-transduced tumor cells secreting GM-CSF and interferon-gamma. 873 94

Platelets and megakaryocytes express Fc receptors for IgG which are encoded by the Fc gamma RIIA gene. In an effort to establish a cellular model for induction of Fc gamma RIIA expression during megakaryocyte development by hematopoietic growth factors, steady-state Fc gamma RIIA mRNA levels were monitored in c-kit receptor-positive megakaryocytic cells (M07e, HEL, and Dami) in response to c-kit ligand (KL; also known as stem cell factor, mast cell growth factor, or Steel factor). Northern blot analysis showed that exposure of cells to KL led to significant increases in Fc gamma RIIA levels in M07e (15 x at 24 hours), with smaller increases in HEL (1.9 x at 2 hours) and Dami (1.6 x at 24 hours) cells. K562 cells, which lack c-kit receptor, showed no effect of KL on modulating Fc gamma RIIA mRNA levels. The effects of KL were specific for Fc gamma RIIA, as there were no effects on platelet factor 4 (PF4), gamma-globin, or GATA-1 mRNA levels. Effects of KL, alone and in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF) and gamma-interferon (IFN-gamma), on surface Fc gamma RIIA expression were assessed by flow cytometry using anti-Fc gamma RII monoclonal antibody IV.3. In M07e cells, KL alone and in combination led to significant increases in the percentage of cells positive for surface Fc gamma RIIA and the mean cell fluorescence intensity. Transient transfection studies of an Fc gamma RIIA promoter-luciferase reporter gene in the presence or absence of KL showed increased reporter gene expression in KL-treated cells, with the largest increase (3.7-fold) in the M07e cells. In HEL and Dami cells, other cytokines active in megakaryocytopoiesis when used alone (interleukin-3 [IL-3], IL-6, IL-11, GM-CSF) had negligible activity in increasing reporter gene activity. These results suggest that increased levels of Fc gamma RIIA mRNA after KL treatment of M07e cells are a result, in part, of increased Fc gamma RIIA gene transcription. Our results indicate that M07e cells represent a cellular model for KL-induced Fc gamma RIIA expression in early megakaryocyte development.
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PMID:Human c-kit ligand (stem cell factor) induces platelet Fc receptor expression in megakaryoblastic cells. 876 99


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