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)

In this study, we analyzed the expression and function of the lymphocyte surface lectin NKRP1A on peripheral blood monocytes (Mo) or Mo and dendritic cells (DC) derived from thymic and bone marrow precursors. De novo expression of NKRP1A and CD14 molecules was detected upon culture of CD2- CD3- CD14- CD16- CD1a- NKRP1A- immature thymic precursors for 7 days in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF). Under these culture conditions, by day 21, a fraction of cells had lost CD14 and acquired both CD80 (B7.1) and CD86 (B7.2) molecules. These cells displayed a DC-like morphology and were surface NKRP1A positive. CD34+ NKRP1A- CD14- precursors, isolated from bone marrow and cultured in the presence of GM-CSF, also expressed both NKRP1A and CD14: these antigens were newly expressed on about one third of cells which had lost the CD34 precursor marker. In addition, NKRP1A was constitutively present on resting CD14+ peripheral blood Mo. When these cells were cultured in the presence of GM-CSF, the resulting DC population retained the expression of NKRP1A and acquired CD80, while they lost the CD14 antigen. Functional analysis revealed that the engagement of NKRP1A molecule leads to a strong intracellular calcium ([Ca2+]i) increase both in resting peripheral blood Mo and in vitro-derived DC. [Ca2+]i increase was mainly due to extracellular calcium influx, as it was completely abrogated by the addition of EGTA. More importantly, the engagement of the NKRP1A molecule induced interleukin (IL)-1 beta and IL-12 production by resting Mo and DC, respectively. Altogether these data indicate that NKRP1A lectin is present at the surface of Mo and DC and may play a relevant role in the activation and function of both cell types.
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PMID:Expression and function of NKRP1A molecule on human monocytes and dendritic cells. 939 25

In an attempt to explore novel treatment modalities in acute myeloid leukemia (AML), we studied the role of costimulatory and cytokine gene immunotherapy in murine AML. We have previously shown that leukemic mice can be cured with CD80 transfected leukemic cells (B7. 1-AML vaccine) administered early in the course of the disease and that the failure B7.1-AML vaccines administered late cannot be attributed to immunosuppression induced by tumor growth. CD8+ T cells, which are necessary for tumor rejection, are activated rather than suppressed during the first half of the leukemic course in nonvaccinated mice. In this report, we question whether CD86 (B7.2) or the cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4), or tumor necrosis factor-alpha (TNF-alpha) can improve the vaccination potential of AML cells. The choice of cytokines was based on their combined and alone as well ability to direct the differentiation of CD34+ cells into potent antigen-presenting dendritic cells in vitro. Our studies show that (1) mice vaccinated with a leukemogenic number of AML cells engineered to express B7.2 (B7.2-AML) or to secrete GM-CSF, IL-4, or TNF-alpha (GM-, IL-4-, TNF-alpha-AML) do not develop leukemia; (2) GM-AML cells are tumorigenic in sublethally irradiated SJL/J mice but not in Swiss nu/nu mice, indicating that killing of tumor cells is not T-cell-dependent; (3) vaccines with irradiated GM-AML, but not B7.2-, IL-4-, or TNF-alpha-AML cells, can elicit leukemia-specific protective and therapeutic immunity; and (4) in head-to-head comparison experiments, vaccination with irradiated GM-AML is more potent than B7.1-AML, curing 80% and providing 20% prolonged survival of the leukemic mice at week 2, as opposed to cures only up to 1 week with B7.1-AML vaccines. These preclinical data emphasize that GM-CSF gene immunotherapy deserves clinical evaluation in AML.
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PMID:Gene immunotherapy in murine acute myeloid leukemia: granulocyte-macrophage colony-stimulating factor tumor cell vaccines elicit more potent antitumor immunity compared with B7 family and other cytokine vaccines. 941 88

Dendritic cells (DC) have been shown to develop along a myeloid or lymphoid lineage of differentiation propagated from bone marrow or early thymic precursor cells with hematopoietic cytokines. In our study, we have induced growth and differentiation of DC from cord blood CD34+ cells initiated in interleukin-2 (IL-2) alone or in IL-2 + stem cell factor (SCF) + tumor necrosis factor alpha (TNF-alpha)-supplemented medium and cultured with IL-2 or IL-2 + SCF for 28-35 days. Dendritic morphology and antigenic phenotype of DC grown with IL-2 were characteristic for DC cultured in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF). Growth and differentiation of DC was followed by an increase in expression of MHC II and co-stimulating molecules CD80 and CD86. We have also shown the expression of the IL-2 receptor (IL-2R) gamma-chain in CD34+ cells after 2-3 days of culture with IL-2 alone. The co-expression of the IL-2R alpha, beta, and gamma subunits in both DC cultured with IL-2- or GM-CSF-containing cocktail of cytokines was also shown. The time curve for induction of IL-2R demonstrated low levels of subunit expression at the beginning of culture. The number of CD1a cells co-expressing CD25, CD122, and CDgamma increased to about 24-68 and to 78-95% after 21 and 28-35 days, respectively. Development of natural killer cells was shown along with DC. The proportion of CD56+ cells and cytotoxicity increased in a time-dependent manner.
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PMID:Interleukin-2-induces development of denditric cells from cord blood CD34+ cells. 958 7

Because dendritic cells (DC) are critically involved in both initiating primary and boosting secondary host immune responses, attention has focused on the use of DC in vaccine strategies to enhance reactivity to tumor-associated antigens. We have reported previously the induction of major histocompatibility complex class II-specific T-cell responses after stimulation with tumor antigen-pulsed DC in vitro. The identification of in vitro conditions that would generate large numbers of DC with more potent antigen-presenting cell (APC) capacity would be an important step in the further development of clinical cancer vaccine approaches in humans. We have focused attention on identifying certain exogenous cytokines added to DC cultures that would lead to augmented human DC number and function. DC progenitors from peripheral blood mononuclear cells (PBMC) were enriched by adherence to plastic, and the adherent cells were then cultured in serum-free XVIVO-15 medium (SFM) for 7 days with added granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). At day 7, cultures contained cells that displayed the typical phenotypic and morphologic characteristics of DC. Importantly, we have found that the further addition of tumor necrosis factor alpha (TNFalpha) at day 7 resulted in a twofold higher yield of DC compared with non-TNFalpha-containing DC cultures at day 14. Moreover, 14-day cultured DC generated in the presence of TNFalpha (when added at day 7) demonstrated marked enhancement in their capacity to stimulate a primary allogeneic mixed leukocyte reaction (8-fold increase in stimulation index [SI]) as well as to present soluble tetanus toxoid and candida albicans (10- to 100-fold increases in SI) to purified CD4+ T cells. These defined conditions allowed for significantly fewer DC and lower concentrations of soluble antigen to be used for the pulsing of DC to efficiently trigger specific T-cell proliferative responses in vitro. When compared with non-TNFalpha-supplemented cultures, these DC also displayed an increased surface expression of CD83 as well as the costimulatory molecules, CD80 and CD86. Removal of TNFalpha from the DC cultures after 2 or 4 days reduced its enhancing effect on DC yield, phenotype, and function. Thus, the continuous presence of TNFalpha over a 7-day period was necessary to achieve the maximum enhancing effect observed. Collectively, our findings point out the importance of exogenous TNFalpha added to cultures of cytokine-driven human DC under serum-free conditions, which resulted in an enhanced number and function of these APC. On the basis of these results, we plan to initiate clinical vaccine trials in patients that use tumor-pulsed DC generated under these defined conditions.
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PMID:The role of tumor necrosis factor alpha in modulating the quantity of peripheral blood-derived, cytokine-driven human dendritic cells and its role in enhancing the quality of dendritic cell function in presenting soluble antigens to CD4+ T cells in vitro. 961 62

The antigen-presenting capacity of dendritic cells (DCs) makes them attractive potential cellular adjuvants for vaccination strategies. Currently, most in vitro culture systems for the production of these DCs include serum. However, this is undesirable because serum contains growth factors that vary between individuals and could affect DC development. Unless the patient's own serum is used, foreign antigens and the risk of infection will detract from the usefulness of these cells in clinical strategies. In this study we investigated the production of DCs from CD34+ progenitor cells of cancer patients or normal donors under serum-free conditions. We have established a model system for the investigation of DC development and maturation. Dendritic cells that developed from myeloid precursors accumulated after 2 weeks in an intermediate CD1a , CD80-, CD83-, CD86- stage. Intermediate DCs adhered to plastic surfaces, expressed Birbeck granules, and were negative for CD2 and CD14. In the presence of granulocyte-macrophage colony-stimulating factor and tumor necrosis factor-alpha, interleukin-4 promoted the development of these stages. Spontaneous maturation of intermediate DCs into fully activated DCs expressing CD83 and costimulatory molecules occurred asynchronously over the ensuing 2 to 3 weeks. This maturation involved increased expression of CD80, CD83, CD86, CMRF-44, HLA-A, -B, -C, and -DR as well as downregulation of CD1a and CD11b. Activated DCs are characterized by the lack of adherence to plastic surfaces and the absence of Birbeck granules. By day 28, these cells were nonphagocytic, potent antigen-presenting cells with an irreversible phenotype. This serum-free system offers advantages in that the process of differentiation and maturation of committed DCs is extended over a period of more than 28 days, allowing investigators to study the effects of individual cytokines or other supplements during distinct phases of DC development in a defined environment.
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PMID:A serum-free culture model for studying the differentiation of human dendritic cells from adult CD34+ progenitor cells. 962 Feb 82

We examined the effect of interleukin (IL)-4 or CD40 ligation on the differentiation and maturation of CD1a+CD14- and CD1a-CD14+ dendritic cell (DC) precursors. Cord blood CD34+ cells were cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF-alpha), to which stem cell factor and Flt-3 ligand were added for 5 days. Phenotypic analysis of DC precursors on culture day 7 showed that CD1a+CD14- cells expressed higher CD11c and CD80 levels and lower CD116/GM-CSFR and CCR-5 levels than their CD1a-CD14+ counterparts. Culturing CD1a+CD14- precursors with GM-CSF and TNF-alpha resulted in DC with heterogeneous CD1a, HLA;SMDR (DR), CD11b, and CD83 expression, 10% of which acquired CD14. IL-4 and CD40 ligation affected their differentiation in contrasting ways: IL-4 induced CD1ahiCD14-DRloCD11b+CD83-S100+ DC with reduced MLR-stimulating capacity, whereas CD40 ligation led to CD1alo/-CD14-CD40-DRhiCD11b-CD83+S100+/- DC with stronger MLR-stimulating capacity. Also, both IL-4 and CD40 ligation promoted ReIB expression and nuclear translocation. When CD1a-CD14+ precursors were maintained in only the presence of GM-CSF and TNF-alpha, this led to mixed populations of adherent macrophages and nonadherent CD1a-CD14+ monocytes, and of CD1a+CD14- and CD1a+CD14+ DC, which were DRloCD11b+CD83-S100-. IL-4 or CD40 ligation prevented their differentiation into macrophages and resulted in DC with phenotypes close to those issued from CD1a+CD14- precursors, with only a minority staying CD14+ but most being S100-; their MLR-stimulating capacity also increased but remained lower than that of DC differentiated from CD1a+CD14- precursors. Thus, IL-4 or CD40 ligation induced CD1a+CD14- and CD1a-CD14+ DC precursors to differentiate into phenotypically close but functionally different DC populations, suggesting that DC function is primarily determined by their origin. The heterogeneity of DC should then be related to different developmental pathways and to different stages of maturation/activation.
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PMID:IL-4 and CD40 ligation affect differently the differentiation, maturation, and function of human CD34+ cell-derived CD1a+CD14- and CD1a-CD14+ dendritic cell precursors in vitro. 971 64

Despite sufficient levels of HLA class I and class II expression, acute myeloid leukemia (AML) cells usually fail to induce a significant T-cell response in vitro. Therefore, we investigated whether in vitro modifications could enhance the T-cell stimulatory properties of AML cells. AML cells were either cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4), and tumor necrosis factor-alpha (TNF-alpha), or transfected with the CD80 (B7.1) gene and used as stimulator cells for primed and unprimed allogeneic T cells. Cytokine treatment increased HLA class I and II expression, but did not induce CD80 on AML cells. Cytokine-treated AML cells efficiently presented nominal and allo-antigens to primed T-cell clones, induced strong T-cell proliferation in HLA mismatched mixed lymphocyte reactions (MLR), but failed to induce primary T-cell responses from an HLA identical bone marrow donor in MLR. In contrast, CD80-transfected AML cells induced T-cell proliferation of HLA-identical bone marrow donor peripheral blood mononuclear cell (PBMC) in primary MLR, allowing the generation of leukemia reactive CD4(+) T-cell lines and clones. The majority of the generated oligoclonal (25 of 35) T-cell cultures showed patient specific reactivity that did not discriminate between patient's leukemic cells and Epstein-Barr virus (EBV)-transformed B cells (EBV-LCL). The remaining 10 oligoclonal T-cell cultures recognized only leukemic cells. One of these latter leukemia reactive oligoclonal T cells was cloned. The majority of the clones (25 of 29) reacted against both leukemic cells and patient's EBV-LCL. A minority of the T-cell clones with the CD4 phenotype (four of 29) showed strong HLA-DP restricted reactivity against leukemic cells, but not against patient's EBV-LCL or against HLA-matched nonleukemic cells, indicating that their target antigens are preferentially expressed by leukemic cells. In conclusion, our study shows that the in vitro allogeneic T-cell response induced by CD80-transfected AML cells is mainly directed against patient's specific minor histocompatibility antigens, while antigens preferentially expressed by leukemic cells can also trigger T-cell responses.
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PMID:CD80-Transfected acute myeloid leukemia cells induce primary allogeneic T-cell responses directed at patient specific minor histocompatibility antigens and leukemia-associated antigens. 971 96

Dendritic cells (DC), the most potent antigen-presenting cells found to date, can be generated from the adherent fraction of peripheral blood mononuclear cells (PBMC) by culture with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4. When interferon gamma (IFN-gamma) was added to the culture medium, the expression of CD1a, CD4 and CD80 markers were significantly reduced, while that of HLA-A, B, C, MHC II (MHC-DR), CD11a and CD54 were increased. T cell proliferation analysis showed that the DC derived from monocytes cultured with GM-CSF, IL-4 and IFN-gamma only induced weak responses in both activated and naive allogenic CD4(+) and CD8(+) T cells when compared to the reaction elicited by DC cultured without IFN-gamma. Furthermore, the DC derived from cultures with IFN-gamma, loaded with an immunogenic peptide derived from the HER2/neu protein [HER2 (9466)], only induced low levels of TNF release and weak proliferative responses in a specific cytotoxic CD8(+) T lymphocyte clone. Therefore, our results indicate that IFN-gamma negatively influences the differentiation and function of monocyte-derived DC by affecting the expression of surface molecules involved in their antigen-presenting function. This supports the general hypothesis that there exists a feedback immune regulatory mechanism between T cells and monocytes/DC.
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PMID:Interferon gamma impairs the ability of monocyte-derived dendritic cells to present tumour-specific and allo-specific antigens and reduces their expression of CD1A, CD80 AND CD4. 981 27

Since dendritic cells (DCs) are the most professional antigen-presenting cells, (Schuler et al., 1997), increasing interest in their use in clinical approaches has been observed. (Nestle et al., 1998; Murphy G. et al., 1996). We have developed an ex vivo standardized process for the generation of dendritic-like cells (MAC-DCs) from human blood circulating monocytes. Human monocytes can differentiate into very different functional cells according to the conditions of culture, media and cytokines used. In the present study, we demonstrate that both pure monocytes and mononuclear cells differentiate into DCs when they are grown in defined medium AIM-V in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) plus IL13 and in approved biocompatible non-adherent bags. Quality and functional controls of the immature DCs obtained rely on bacterial sterility, viability, morphology and recovery. The MAC-DCs also present an immature DC phenotype with a low expression of CD14 and CD64, and high expression of MHC-I, MHC-II and CD40. They also express B7 costimulatory molecules (CD80, CD86), CD83, and CD1a molecules. They induce strong allogenic T-cell proliferation (mixed lymphocyte reaction as well as proliferation of autologous memory T lymphocytes when incubated in the presence of recall antigens (tuberculosis, Candida albicans, and tetanus toxoid). They also show an increase in phagocytic uptake of yeast, tumour cells and debris. The global closed system which, under reproducible good medical practice (GMP) conditions, enables the production of dendritic cells of clinical quality, has been optimized ("Vac Cell Processor"). It contains all bags, connections, media, reagents, washing solutions, control antibodies, standard operating procedures, data management, traceability and help in the form of dedicated software.
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PMID:Monocyte-derived dendritic cells: development of a cellular processor for clinical applications. 985 16

Ligation of either CD80 (B7-1) or CD86 (B7-2), two principal ligands for CD28, is thought to skew the immune response toward Th1 or Th2 differentiation. We have examined early signal transduction pathways recruited following T cell stimulation with either CD80 or CD86. Purified human peripheral T cells or Jurkat T cells were stimulated with Chinese hamster ovary (CHO) cells expressing either human CD80 (CHO-CD80) or human CD86 (CHO-CD86) or with anti-CD28 monoclonal antibody (mAb). In the presence of phorbol 12-myristate 13-acetate, both CHO-CD80 and CHO-CD86, like anti-CD28 mAb, were capable of stimulating cytokine production from both human peripheral T cells and Jurkat T cells. Both CHO-CD80 and CHO-CD86, in the presence of anti-CD3 mAb, costimulated NFAT-dependent transcriptional activation. Several intracellular signaling proteins, such as CBL and VAV, were phosphorylated on tyrosine in response to CD80, CD86, and anti-CD28 mAb. Surprisingly, although stimulation of Jurkat T cells with either CHO-CD80 or anti-CD28 mAb resulted in robust tyrosine phosphorylation of CD28 itself, ligation with CHO-CD86 was unable to induce detectable CD28 tyrosyl phosphorylation over a range of stimulation conditions. In addition, the association of phosphoinositide 3-kinase with CD28 and enhanced tyrosine phosphorylation of phospholipase Cgamma were seen after anti-CD28 mAb and CHO-CD80 stimulation but to a much lesser extent after CHO-CD86 stimulation. Thus, ligation of CD28 with either CD80 or CD86 leads to shared early signal transduction events such as the tyrosine phosphorylation of CBL and VAV, to NFAT-mediated transcriptional activation, and to the costimulation of interleukin-2 and granulocyte-macrophage colony-stimulating factor production. However, CD80 and CD86 also induce distinct signal transduction pathways including the tyrosine phosphorylation of CD28 and phospholipase Cgamma1 and the SH2-dependent association of phosphoinositide 3-kinase with CD28. These quantitative, if not qualitative, differences between signaling initiated by these two ligands for CD28 may contribute to functional differences (e.g. Th1 or Th2 differentiation) in T cell responses.
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PMID:CD80 and CD86 are not equivalent in their ability to induce the tyrosine phosphorylation of CD28. 991 50


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