title: The honeybee antimicrobial peptide apidaecin differentially immunomodulates human macrophages, monocytes and dendritic cells.
abstract: We show that apidaecin binds to human macrophages, monocytes and dendritic cells, displaying different intracellular distributions and inducing diversified effects. An apidaecin-cell association was detectable at concentrations as low as 5 μM and increased without saturation until 60 μM, was receptor independent and required a physiological temperature (37°C). For apidaecin, cytosolic localization was prevalent in macrophages and endosomal localization in monocytes, and associations with the plasma membrane were predominant in dendritic cells. Apidaecin upregulated T-lymphocyte co-stimulatory molecule CD80 and cytokine/chemokine production in macrophages, but not in monocytes and dendritic cells. Suboptimal stimulatory doses (5-10 μM) of apidaecin partially inhibited the lipopolysaccharide (LPS)-induced increase in major histocompatibility complex class II (MHCII) and CD86 in macrophages, and the release of selected cytokines/chemokines by both macrophages [interleukin (IL)-6 and tumor necrosis factor (TNF)-α] and monocytes [IL-6, TNF-α, basic fibroblast growth factor (FGF) and eotaxin]. Apidaecin had a double-edged effect: at low concentrations it partially antagonized LPS-stimulatory effects on both macrophages and monocytes while it stimulated pro-inflammatory and pro-immune functions of macrophages at higher concentrations.
authors.affiliation: Centro di Ricerca Interdipartimentale per le Biotecnologie Innovative, Padova, Italy. regina.tavano@unipd.it
authors.forename: Regina
authors.initials: R
authors.lastname: Tavano
authors.forename: Daniela
authors.initials: D
authors.lastname: Segat
authors.forename: Marina
authors.initials: M
authors.lastname: Gobbo
authors.forename: Emanuele
authors.initials: E
authors.lastname: Papini
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D001516:Bees / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D004306:Dose-Response Relationship, Immunologic; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D006801:Humans; D056747:Immunomodulation; D008070:Lipopolysaccharides / Q000276:immunology / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D009000:Monocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D021381:Protein Transport
chemical_list: D015703:Antigens, CD; D023181:Antimicrobial Cationic Peptides; D016207:Cytokines; D008070:Lipopolysaccharides; C061361:apidaecin