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)

Previous studies in our laboratory have shown that bone-marrow-derived mast cells (BMMC) could present immunogenic peptides, from soluble antigens endocytosed through fluid phase, only if they were subjected to a 48-hr treatment with interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF). In contrast to GM-CSF, interferon-gamma (IFN-gamma) which highly upregulates major histocompatibility complex (MHC) class II expression, completely inhibits the generation of immunogenic peptides. We have used this model to study the role of FcepsilonRI-mediated antigen internalization in the regulation of the antigen-presenting function of IFN-gamma-treated mast cells. Here, we report that FcepsilonRI can reverse the IFN-gamma-treated mast cells from inefficient to highly efficient antigen-presenting cells. Inhibition of the antigen presenting capacity by piceatannol, a protein tyrosine kinase (PTK) syk inhibitor, indicates that this is an active process resulting from immunoglobulin E (IgE)-antigen-FcepsilonRI engagement which involves tyrosines found in the immunoreceptor tyrosine-based activation motif (ITAM) embedded in the cytoplasmic tail of the FcepsilonRI beta and gamma chains. Antigen-presenting function was also shown to require the activation of phosphatidyl inositol 3 (PI3) kinase, downstream of PTK syk phosphorylation, since this activity was completely blocked by wortmannin, a PI3 kinase inhibitor. These data suggest that signalling generated by FcepsilonRI provides mast cells with IgE-mediated enhanced antigen presentation to T cells and emphasize a so far unknown immunoregulatory mast-cell function that might take place in inflammatory sites.
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PMID:FcepsilonRI-mediated antigen endocytosis turns interferon-gamma-treated mouse mast cells from inefficient into potent antigen-presenting cells. 1044 50

Dendritic cells (DCs) are the most powerful of all antigen-presenting cells and play a critical role in the induction of primary immune responses. DC-based vaccination represents a potentially powerful strategy for cancer immunotherapy. In this study, a new approach for a DC-based melanoma vaccine was described. Splenic DCs from C57BL/6 mice were fused with B16 melanoma cells, and the resultant B16/DC hybrid cells expressed major histocompatibility complex (MHC) molecules - B7 as well as the B16 tumour marker M562 - which were enriched by Ia-mediated positive selection with a MiniMACS column. The fusion rates were 12.7-26.8%. To generate hybrid tumour vaccines with potentially greater potent therapeutic efficacy, we genetically engineered DCs with granulocyte-macrophage colony-stimulating factor (GM-CSF) prior to cell fusion. Recombinant adenovirus vector was used to mediate gene transfer into DCs with high efficiency and DCs expressed GM-CSF at 96-138 ng/105 cells/ml 24 hr after GM-CSF gene transfer. GM-CSF gene-modified DCs (DC.GM) exhibited higher expression of B7 and co-stimulatory capacity in mixed lymphocyte reaction (MLR). Fusion of DC.GM with B16 cells generated B16/DC.GM hybrid cells secreting GM-CSF at 59-63 ng/105 cells/ml. Immunization of C57BL/6 mice with the B16/DC hybrid vaccine elicited a specific cytotoxic T-lymphocyte (CTL) response and protected the immunized mice from B16 tumour challenge, reduced pulmonary metastases and extended the survival of B16 tumour-bearing mice. The B16/DC.GM hybrid vaccine was able to induce a CTL response and protective immunity more potently and tended to be therapeutically more efficacious than the B16/DC vaccine. In vivo depletion of T-cell subsets demonstrated that both CD8+ and CD4+ T cells were essential for the therapeutic effects of B16/DC and B16/DC.GM hybrid vaccines. Additionally, other non-specific effector cells may also contribute to tumour rejection induced by the B16/DC.GM hybrid vaccine. These data indicate that a DC-based hybrid tumour vaccine may be an attractive strategy for cancer immunotherapy, and that GM-CSF gene-modified DCs may lead to the generation of hybrid vaccines with potentially increased therapeutic efficacy.
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PMID:Therapy of established tumour with a hybrid cellular vaccine generated by using granulocyte-macrophage colony-stimulating factor genetically modified dendritic cells. 1045 15

Alveolar macrophages (AM) present antigen poorly to CD4+ T cells and respond weakly to interferon-gamma (IFN-gamma) for up-regulation of major histocompatibility complex (MHC) class II and costimulatory molecule expression. In atopic asthma, however, AM exhibit enhanced antigen-presenting cell (APC) activity. Since granulocyte-macrophage colony-stimulating factor (GM-CSF) is increased in the airways of asthmatic patients, we have investigated its role in modulating the APC function of AM. The effects of glucocorticoids were also studied since earlier studies showed optimal induction of MHC antigens on monocytes by GM-CSF in their presence. GM-CSF in the presence, but not the absence, of dexamethasone enhanced the expression of HLA-DR, -DP and -DQ antigens by AM. However AM and monocytes differed in the optimal concentration of steroid required to mediate this effect (10-10 m and 10-7 m, respectively). Induction of MHC antigens was glucocorticoid specific and independent of IFN-gamma. These studies suggest the existence of an IFN-gamma-independent pathway of macrophage activation, which may be important in regulating APC function within the lung.
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PMID:Regulation of major histocompatibility complex class II antigens on human alveolar macrophages by granulocyte-macrophage colony-stimulating factor in the presence of glucocorticoids. 1046 40

Culture of bone marrow precursor cells with cytokines, including granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4) and the tyrosine kinase receptor binding proteins Flt-3 ligand (Flt-3L) and stem-cell factor (SCF), has previously been shown, in both mouse and human, to result in the generation of large numbers of dendritic cells. We extend these findings to bovine dendritic cells. Culture of bovine bone marrow cells with GM-CSF, IL-4 and either Flt-3L or SCF enhanced the generation of low buoyant-density dendritic cells. However, only the addition of Flt-3L to cells cultured with GM-CSF and IL-4 was shown to increase the number of dendritic cells and induce the differentiation of dendritic cells with potent capacity to stimulate allogeneic T cells and resting CD4+ memory T cells. The effective ability to stimulate T cells was associated with the expression of major histocompatibility complex (MHC) class II molecules and CD80/86 by dendritic cells. Bovine bone marrow derived dendritic cells appeared to be exclusively of myeloid origin because they expressed the myeloid-related antigens CD14, MyD-1 and CD11b.
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PMID:Flt-3 ligand, in combination with bovine granulocyte-macrophage colony-stimulating factor and interleukin-4, promotes the growth of bovine bone marrow derived dendritic cells. 1063 77

The ets-family transcription factor PU.1 is required for the proper development of both myeloid and lymphoid progenitors. We used PU. 1-deficient animals to examine the role of PU.1 during dendritic cell development. PU.1(-/-)animals produce lymphoid-derived dendritic cells (DC): low-density class II major histocompatibility complex [MHC-II(+)] CD11c(+) CD8alpha(+) DEC-205(+). But they lack myeloid-derived DC: low-density MHC-II(+) CD11c(+) CD8alpha(-) DEC-205(-). PU.1(-/-) embryos also lack progenitors capable of differentiating into myeloid DC in response to granulocyte-macrophage colony-stimulating factor plus interleukin-4. The appearance of lymphoid DC in developing PU.1(-/-)thymus was initially delayed, but this population recovered to wild type (WT) levels upon organ culture of isolated thymic lobes. PU. 1(-/-)lymphoid DC were functionally equivalent to WT DC for stimulating T-cell proliferation in mixed lymphocyte reactions. These results demonstrate that PU.1 is required for the development of myeloid DC but not lymphoid DC.
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PMID:PU.1 is required for myeloid-derived but not lymphoid-derived dendritic cells. 1064 99

DNA vaccines containing genes for antigenic portions of viruses have recently been developed as a novel vaccination technology. Direct injection of plasmid DNA in vivo results in prolonged expression of viral proteins and may, thus, mimic the action of attenuated vaccines. An important advantage of this vaccination method is that in vivo-synthesized viral proteins can enter both major histocompatibility complex (MHC) class I and class II antigen-processing pathways to activate specific immunization. In many animal models for infectious diseases, DNA vaccines induced a broad range of immune responses, including antibody, CD8+ cytotoxic T lymphocytes (CTL) and CD4+ helper T (Th) lymphocyte responses, and protective immunity against challenge with the pathogen. The magnitude and nature of these immune responses to DNA vaccines can be further manipulated by codelivery of cytokine genes. Summarizing the many studies reported to date, we can draw conclusions regarding the adjuvant effects of these cytokine genes on DNA vaccines. Coadministration of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-2 genes induces higher antibody titers and T-cell proliferation responses than other cytokine genes tested to date. In contrast, the CTL activity is only modestly increased by the GM-CSF and IL-2 genes. The IL-12 gene polarizes the immune responses to DNA vaccines toward Th1 cell development and stimulates the strongest CTL activity. In contrast, co-injection of the IL-4 gene promotes the development of Th2 cells and increases production of antibodies, but suppresses CTL activity. Thus, the immune responses to DNA vaccines can be engineered by co-injection of an appropriate cytokine gene to favor the formation of either CTL or neutralization antibodies and, therefore, provide the best protection against a particular pathogen.
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PMID:Modulation of immune responses to DNA vaccines by codelivery of cytokine genes. 1070 87

Prolactin (PRL) shares structural and functional features with haemopoietic factors and cytokine peptides. Dendritic cells (DC) are involved in both initiating the primary and boosting the secondary host immune response and can be differentiated in vitro from precursors under the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) plus other factors. Because PRL has been shown to functionally interact with GM-CSF, we have addressed its role on GM-CSF-driven differentiation of DC. Monocytic DC precursors from peripheral blood mononuclear cells (PBMC) were enriched either by adhesion to a plastic surface or CD14-positive selection and cultured for 7 days in serum-free medium containing GM-CSF, interleukin (IL)-4 and PRL, alone or in combination. Cells with large, veiled cytoplasm, expressing major histocompatibility complex (MHC) class II and the costimulatory molecules CD80, CD86 and CD40 and lacking the monocyte marker CD14, were considered as having the phenotype of cytokine-generated DC. Functional maturation was assessed by proliferation and interferon-gamma (IFN-gamma) release of allogeneic T lymphocytes. Physiological (10-20 ng/ml) concentrations of PRL interacted synergistically with GM-CSF and the effect was similar to that induced by IL-4 on GM-CSF-driven DC maturation. When used alone, the physiological concentrations of PRL were inhibitory, whereas higher concentrations (80 ng/ml) were stimulatory. The synergistic effect of PRL may in part be caused by its ability to counteract the down-modulation of the GM-CSF receptor observed in serum-free conditions. These data provide further evidence of the significance of PRL in the process of T lymphocyte activation.
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PMID:Individual and combined effect of granulocyte-macrophage colony-stimulating factor and prolactin on maturation of dendritic cells from blood monocytes under serum-free conditions. 1080 56

The identification of tumor-associated antigens recognized by cellular or humoral effectors of the immune system has opened new perspectives for cancer therapy. Different groups of cancer-associated antigens have been described as targets for cytotoxic T lymphocytes (CTLs) in vitro and in vivo: 1) cancer-testis (CT) antigens, which are expressed in different tumors and normal testis; 2) melanocyte differentiation antigens; 3) point mutations of normal genes; 4) antigens that are overexpressed in malignant tissues; and 5) viral antigens. Clinical studies with peptides derived from these antigens have been initiated to induce specific CTL responses in vivo. Immunological and clinical parameters for the assessment of peptide-specific reactions have been defined, i.e., delayed-type hypersensitivity (DTH), CTL, autoimmmune, and tumor regression responses. Preliminary results demonstrate that tumor-associated peptides alone elicit specific DTH and CTL responses leading to tumor regression after intradermal injection. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was proven effective in enhancing peptide-specific immune reactions by amplification of dermal peptide-presenting dendritic cells. Long-lasting complete tumor regressions have been observed after induction of peptide-specific CTLs. However, in single cases with disease progression after an initial tumor response, either a loss of the respective tumor antigen targeted by CTLs or of the presenting major histocompatibility complex (MHC) class I allele was detected as a mechanism of immune escape under immunization. Based on these observations, cytokines to enhance antigen and MHC class I expression in vivo are being evaluated to prevent immunoselection. Recently, a strategy utilizing spontaneous antibody responses to tumor-associated antigens (SEREX) has led to the identification of a new CT antigen, NY-ESO-1, which is regarded as one of the most immunogenic antigens known today inducing spontaneous immune responses in 50% of patients with NY-ESO-1-expressing cancers. Clinical studies involving antigenic constructs that induce both antibody and CTL responses will show whether these are more effective for immunotherapy of cancer.
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PMID:Cancer immunotherapy in clinical oncology. 1095 Jan 48

Mouse bone marrow-derived myeloid dendritic cells (DC) propagated in granulocyte-macrophage colony-stimulating factor and transforming growth factor-beta1 (TGF-beta1) (so-called 'TGF-beta DC') are phenotypically immature, and prolong allograft survival. Interleukin-10 (IL-10) has been shown to inhibit the maturation of DC by down-regulating surface major histocompatibility complex (MHC) class II, co-stimulatory and adhesion molecule expression. Genetic engineering of TGF-beta DC to overexpress IL-10 might enhance their tolerogenic potential. In this study, adenoviral (Ad) vectors encoding the mouse IL-10 gene were transduced into B10 (H2b) TGF-beta DC. Transduction with Ad-IL-10 at a multiplicity of infection (MOI) of 50-100 resulted in a modest reduction in the incidence of DC expressing surface MHC class II, CD40, CD80 and CD86. Paradoxically, Ad-IL-10 transduction enhanced the allostimulatory activity of DC in mixed leucocyte reactions and cytotoxic T lymphocyte assays, and increased their natural killer cell stimulatory activity. Systemic injection of normal C3H recipients with Ad-IL-10-transduced B10-DC 7 days before organ transplantation, exacerbated heart graft rejection and augmented circulating anti-donor alloantibody titres. Contrasting effects were observed in relation to tumour growth. All mice preimmunized with Ad-IL-10-transduced, tumour antigen (B16F10)-pulsed DC developed palpable tumours, associated with significant inhibition of splenic anti-tumour cytotoxic T lymphocyte generation. Animals pretreated with control Ad-LacZ-transduced, B16F10-pulsed DC however, remained tumour free. These findings are consistent with the multifunctional immunomodulatory properties of mammalian IL-10.
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PMID:Contrasting effects of myeloid dendritic cells transduced with an adenoviral vector encoding interleukin-10 on organ allograft and tumour rejection. 1101 77

Murine dendritic cells (DCs) can be classified into at least 2 subsets, "myeloid-related" (CD11b(bright), CD8alpha(-)) and "lymphoid-related" (CD11b(dull), CD8alpha(+)), but the absolute relationship between the 2 remains unclear. Methods of generating DCs from bone marrow (BM) precursors in vitro typically employ granulocyte-macrophage colony-stimulating factor (GM-CSF) as the principal growth factor, and the resultant DCs exhibit a myeloidlike phenotype. Here we describe a flt3-ligand (FL)-dependent BM culture system that generated DCs with more diverse phenotypic characteristics. Murine BM cells cultured at high density in recombinant human FL for 9 days developed into small lymphoid-sized cells, most of which expressed CD11c, CD86, and major histocompatibility complex (MHC) class II. The CD11c(+) population could be divided into 2 populations on the basis of the level of expression of CD11b, which may represent the putative myeloid- and lymphoid-related subsets. The FL in vitro-derived DCs, when treated with interferon-alpha or lipopolysaccharide during the final 24 hours of culture, expressed an activated phenotype that included up-regulation of MHC class II, CD1d, CD8alpha, CD80, CD86, and CD40. The FL-derived DCs also exhibited potent antigen-processing and antigen-presenting capacity. Neutralizing anti-interleukin-6 (IL-6) antibody, but not anti-GM-CSF, significantly reduced the number of DCs generated in vitro with FL, suggesting that IL-6 has a role in the development of DCs from BM precursors. Stem cell factor, which exhibits some of the same bioactivities as FL, was unable to replace FL to promote DC development in vitro. This culture system will facilitate detailed analysis of murine DC development.
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PMID:Generation of murine dendritic cells from flt3-ligand-supplemented bone marrow cultures. 1104 81


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