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Jean-marc Reichhart - One of the best experts on this subject based on the ideXlab platform.

  • insect immunity the diptericin promoter contains multiple functional regulatory sequences homologous to mammalian acute phase response elements
    Biochemical and Biophysical Research Communications, 1993
    Co-Authors: Philippe Georgel, Marie Meister, Christine Kappler, Bruno Lemaitre, Jean-marc Reichhart
    Abstract:

    We are using the diptericin gene as a model system to study the control of expression of the genes encoding antibacterial peptides during the Drosophila immune reaction. In order to investigate the putative regulatory regions in the diptericin promoter, we performed DNaseI footprinting experiments combined with gel-shift assays in two inducible systems: the larval fat body and a tumorous Drosophila Blood Cell Line. Our results confirm the importance of kappa B-like elements previously described in the immune response of insects and reveal for the first time the involvement of other regions containing sequences homologous to mammalian acute-phase response elements.

  • insect immunity two 17 bp repeats nesting a kappa b related sequence confer inducibility to the diptericin gene and bind a polypeptide in bacteria challenged drosophila
    The EMBO Journal, 1993
    Co-Authors: Christine Kappler, Marie Meister, Jules A Hoffmann, Marie Lagueux, E Gateff, Jean-marc Reichhart
    Abstract:

    The Drosophila diptericin gene codes for a 9 kDa antibacterial peptide and is rapidly and transiently expressed in larvae and adults after bacterial challenge. It is also induced in a tumorous Drosophila Blood Cell Line by the addition of lipopolysaccharide (LPS). The promoter of this gene contains two 17 bp repeats located closely upstream of the TATA-box and harbouring a decameric kappa B-related sequence. This study reports that the replacement of the two 17 bp repeats by random sequences abolishes bacteria inducibility in transgenic fly Lines. In transfected tumorous Blood Cells, the replacement of both or either of the 17 bp motifs reduces dramatically LPS inducibility, whereas multiple copies significantly increase the level of transcriptional activation by LPS challenge. A specific DNA-protein binding activity is evidenced in cytoplasmic and nuclear extracts of induced Blood Cells and fat body. It is absent in controls. It is proposed that induction of the diptericin gene mediated by the two 17 bp repeats occurs via a mechanism similar to that of mammalian NF-kappa B.

Stefan G E Roberts - One of the best experts on this subject based on the ideXlab platform.

  • wt1 and its transcriptional cofactor basp1 redirect the differentiation pathway of an established Blood Cell Line
    Biochemical Journal, 2011
    Co-Authors: Sarah J Goodfellow, Michelle R Rebello, Eneda Toska, Leo A H Zeef, Sean G Rudd, Kathryn F Medler, Stefan G E Roberts
    Abstract:

    The Wilms' tumour suppressor WT1 (Wilms' tumour 1) is a transcriptional regulator that plays a central role in organogenesis, and is mutated or aberrantly expressed in several childhood and adult malignancies. We previously identified BASP1 (brain acid-soluble protein 1) as a WT1 cofactor that suppresses the transcriptional activation function of WT1. In the present study we have analysed the dynamic between WT1 and BASP1 in the regulation of gene expression in myelogenous leukaemia K562 Cells. Our findings reveal that BASP1 is a significant regulator of WT1 that is recruited to WT1-binding sites and suppresses WT1-mediated transcriptional activation at several WT1 target genes. We find that WT1 and BASP1 can divert the differentiation programme of K562 Cells to a non-Blood Cell type following induction by the phorbol ester PMA. WT1 and BASP1 co-operate to induce the differentiation of K562 Cells to a neuronal-like morphology that exhibits extensive arborization, and the expression of several genes involved in neurite outgrowth and synapse formation. Functional analysis revealed the relevance of the transcriptional reprogramming and morphological changes, in that the Cells elicited a response to the neurotransmitter ATP. Taken together, the results of the present study reveal that WT1 and BASP1 can divert the Lineage potential of an established Blood Cell Line towards a Cell with neuronal characteristics.

Marie Meister - One of the best experts on this subject based on the ideXlab platform.

  • pvf2 a pdgf vegf like growth factor induces hemocyte proliferation in drosophila larvae
    EMBO Reports, 2002
    Co-Authors: Anneisabelle Munier, Marie Meister, Daniel Doucet, Emmanuel Perrodou, Daniel Zachary, Jules A Hoffmann, Charles A Janeway, Marie Lagueux
    Abstract:

    Blood Cells play a crucial role in both morphogenetic and immunological processes in Drosophila, yet the factors regulating their proliferation remain largely unknown. In order to address this question, we raised antibodies against a tumorous Blood Cell Line and identified an antigenic determinant that marks the surface of prohemocytes and also circulating plasmatocytes in larvae. This antigen was identified as a Drosophila homolog of the mammalian receptor for platelet-derived growth factor (PDGF)/vascular endothelial growth factor (VEGF). The Drosophila receptor controls Cell proliferation in vitro. By overexpressing in vivo one of its putative ligands, PVF2, we induced a dramatic increase in circulating hemocytes. These results identify the PDGF/VEGF receptor homolog and one of its ligands as important players in Drosophila hematopoiesis.

  • insect immunity the diptericin promoter contains multiple functional regulatory sequences homologous to mammalian acute phase response elements
    Biochemical and Biophysical Research Communications, 1993
    Co-Authors: Philippe Georgel, Marie Meister, Christine Kappler, Bruno Lemaitre, Jean-marc Reichhart
    Abstract:

    We are using the diptericin gene as a model system to study the control of expression of the genes encoding antibacterial peptides during the Drosophila immune reaction. In order to investigate the putative regulatory regions in the diptericin promoter, we performed DNaseI footprinting experiments combined with gel-shift assays in two inducible systems: the larval fat body and a tumorous Drosophila Blood Cell Line. Our results confirm the importance of kappa B-like elements previously described in the immune response of insects and reveal for the first time the involvement of other regions containing sequences homologous to mammalian acute-phase response elements.

  • insect immunity two 17 bp repeats nesting a kappa b related sequence confer inducibility to the diptericin gene and bind a polypeptide in bacteria challenged drosophila
    The EMBO Journal, 1993
    Co-Authors: Christine Kappler, Marie Meister, Jules A Hoffmann, Marie Lagueux, E Gateff, Jean-marc Reichhart
    Abstract:

    The Drosophila diptericin gene codes for a 9 kDa antibacterial peptide and is rapidly and transiently expressed in larvae and adults after bacterial challenge. It is also induced in a tumorous Drosophila Blood Cell Line by the addition of lipopolysaccharide (LPS). The promoter of this gene contains two 17 bp repeats located closely upstream of the TATA-box and harbouring a decameric kappa B-related sequence. This study reports that the replacement of the two 17 bp repeats by random sequences abolishes bacteria inducibility in transgenic fly Lines. In transfected tumorous Blood Cells, the replacement of both or either of the 17 bp motifs reduces dramatically LPS inducibility, whereas multiple copies significantly increase the level of transcriptional activation by LPS challenge. A specific DNA-protein binding activity is evidenced in cytoplasmic and nuclear extracts of induced Blood Cells and fat body. It is absent in controls. It is proposed that induction of the diptericin gene mediated by the two 17 bp repeats occurs via a mechanism similar to that of mammalian NF-kappa B.

Christine Kappler - One of the best experts on this subject based on the ideXlab platform.

  • insect immunity the diptericin promoter contains multiple functional regulatory sequences homologous to mammalian acute phase response elements
    Biochemical and Biophysical Research Communications, 1993
    Co-Authors: Philippe Georgel, Marie Meister, Christine Kappler, Bruno Lemaitre, Jean-marc Reichhart
    Abstract:

    We are using the diptericin gene as a model system to study the control of expression of the genes encoding antibacterial peptides during the Drosophila immune reaction. In order to investigate the putative regulatory regions in the diptericin promoter, we performed DNaseI footprinting experiments combined with gel-shift assays in two inducible systems: the larval fat body and a tumorous Drosophila Blood Cell Line. Our results confirm the importance of kappa B-like elements previously described in the immune response of insects and reveal for the first time the involvement of other regions containing sequences homologous to mammalian acute-phase response elements.

  • insect immunity two 17 bp repeats nesting a kappa b related sequence confer inducibility to the diptericin gene and bind a polypeptide in bacteria challenged drosophila
    The EMBO Journal, 1993
    Co-Authors: Christine Kappler, Marie Meister, Jules A Hoffmann, Marie Lagueux, E Gateff, Jean-marc Reichhart
    Abstract:

    The Drosophila diptericin gene codes for a 9 kDa antibacterial peptide and is rapidly and transiently expressed in larvae and adults after bacterial challenge. It is also induced in a tumorous Drosophila Blood Cell Line by the addition of lipopolysaccharide (LPS). The promoter of this gene contains two 17 bp repeats located closely upstream of the TATA-box and harbouring a decameric kappa B-related sequence. This study reports that the replacement of the two 17 bp repeats by random sequences abolishes bacteria inducibility in transgenic fly Lines. In transfected tumorous Blood Cells, the replacement of both or either of the 17 bp motifs reduces dramatically LPS inducibility, whereas multiple copies significantly increase the level of transcriptional activation by LPS challenge. A specific DNA-protein binding activity is evidenced in cytoplasmic and nuclear extracts of induced Blood Cells and fat body. It is absent in controls. It is proposed that induction of the diptericin gene mediated by the two 17 bp repeats occurs via a mechanism similar to that of mammalian NF-kappa B.

Bruno Lemaitre - One of the best experts on this subject based on the ideXlab platform.

  • insect immunity the diptericin promoter contains multiple functional regulatory sequences homologous to mammalian acute phase response elements
    Biochemical and Biophysical Research Communications, 1993
    Co-Authors: Philippe Georgel, Marie Meister, Christine Kappler, Bruno Lemaitre, Jean-marc Reichhart
    Abstract:

    We are using the diptericin gene as a model system to study the control of expression of the genes encoding antibacterial peptides during the Drosophila immune reaction. In order to investigate the putative regulatory regions in the diptericin promoter, we performed DNaseI footprinting experiments combined with gel-shift assays in two inducible systems: the larval fat body and a tumorous Drosophila Blood Cell Line. Our results confirm the importance of kappa B-like elements previously described in the immune response of insects and reveal for the first time the involvement of other regions containing sequences homologous to mammalian acute-phase response elements.