title: Synergistic regulation of Pseudomonas aeruginosa-induced cytokine production in human monocytes by mannose receptor and TLR2.
abstract: The immune response to pathogen is regulated by a combination of specific PRR, which are involved in pathogen recognition. Pseudomonas aeruginosa, a bacterium that causes life-threatening disease in immuno-compromised host, is recognized by distinct members of the TLR family. We have previously shown that viable P. aeruginosa bacteria are recognized by human monocytes mainly through TLR2. Using ligand-specific blocking antibodies, we herein show that the mannose receptor (MR), a phagocytic receptor for unopsonized P. aeruginosa bacteria, contributes equally to TLR2 in proinflammatory cytokine production by human monocytes in response to P. aeruginosa infection. Synergy of both receptors totally controls the immune response. Viable P. aeruginosa bacteria activate NF-kappaB and MAPK pathways and enhance TLR2-mediated signaling in MR-transfected human embryonic kidney 293 cells. Moreover, MR follows the same kinetics and colocalizes with TLR2 in the endosome during in vivo infection of human macrophages with P. aeruginosa. The studies provide the first demonstration of a significant role for MR, synergistic with TLR2, in activating a proinflammatory response to P. aeruginosa infection.
authors.affiliation: Department of Microbiology, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Panagiota
authors.initials: P
authors.lastname: Xaplanteri
authors.forename: George
authors.initials: G
authors.lastname: Lagoumintzis
authors.forename: George
authors.initials: G
authors.lastname: Dimitracopoulos
authors.forename: Fotini
authors.initials: F
authors.lastname: Paliogianni
mesh_terms: D002460:Cell Line; D002478:Cells, Cultured; D006801:Humans; D053583:Interleukin-1beta / Q000096:biosynthesis / Q000276:immunology; D015850:Interleukin-6 / Q000096:biosynthesis / Q000276:immunology; D037181:Lectins, C-Type / Q000276:immunology* / Q000378:metabolism; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000276:immunology* / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D010587:Phagocytosis / Q000276:immunology; D017346:Protein Serine-Threonine Kinases / Q000276:immunology / Q000378:metabolism; D011552:Pseudomonas Infections / Q000276:immunology* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000276:immunology; D011956:Receptors, Cell Surface / Q000276:immunology* / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000276:immunology* / Q000378:metabolism; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology; D000097782:NF-kappaB-Inducing Kinase
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D020929:Mitogen-Activated Protein Kinase Kinases; D017346:Protein Serine-Threonine Kinases; D011956:Receptors, Cell Surface; D051195:Toll-Like Receptor 2; D014409:Tumor Necrosis Factor-alpha; D000097782:NF-kappaB-Inducing Kinase; C508600:IL6 protein, human; C495342:TLR2 protein, human