title: Effect of antimicrobial peptides from Apis mellifera hemolymph and its optimized version Api88 on biological activities of human monocytes and mast cells.
abstract: Apidaecin peptides are produced by the honeybee Apis mellifera as a major part of its non-specific defense system against infections. Having verified that the peptides apidaecin 1b and Api88-a designer peptide based on the native apidaecin 1b sequence-are highly active against Gram-negative bacteria, we studied their ability to modulate biological activities of human monocytes and mast cells (MC), two important cell types of the human innate immune system. We could show that both peptides are nontoxic and fairly resistant to degradation in cell culture medium containing 10% FBS. Among the peptides tested we found Api88 to inhibit LPS-induced TNF-α production in a concentration-dependent manner. Resting monocytes did not respond to Api88. Whilst Api88 neither induced migration nor affected the phagocytic activity of monocytes it partially inhibited the generation of reactive oxygen intermediates produced in response to LPS. In human MC, however, Api88 triggered degranulation and the mobilization of intracellular Ca(2+)-ions. Taken together these data clearly indicate that Api88 is a multifunctional molecule that can modulate biological responses of human monocytes and MC in addition to its antimicrobial activity.
authors.affiliation: Institute of Biology, Universität Leipzig, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Keitel
authors.forename: Erik
authors.initials: E
authors.lastname: Schilling
authors.forename: Daniel
authors.initials: D
authors.lastname: Knappe
authors.forename: Moath
authors.initials: M
authors.lastname: Al-Mekhlafi
authors.forename: Frank
authors.initials: F
authors.lastname: Petersen
authors.forename: Ralf
authors.initials: R
authors.lastname: Hoffmann
authors.forename: Sunna
authors.initials: S
authors.lastname: Hauschildt
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001516:Bees / Q000737:chemistry*; D020013:Calcium Signaling; D015550:Cell Degranulation; D002478:Cells, Cultured; D006458:Hemolymph / Q000378:metabolism; D006801:Humans; D019476:Insect Proteins / Q000138:chemical synthesis / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000276:immunology; D008407:Mast Cells / Q000187:drug effects* / Q000276:immunology; D009000:Monocytes / Q000187:drug effects* / Q000276:immunology; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology*; D055550:Protein Stability; D017382:Reactive Oxygen Species / Q000378:metabolism; D017385:Sequence Homology
chemical_list: D023181:Antimicrobial Cationic Peptides; D019476:Insect Proteins; D008070:Lipopolysaccharides; D010446:Peptide Fragments; D017382:Reactive Oxygen Species; C061361:apidaecin
keywords: Apidaecin; TNF-α; lipopolysaccharide; mast cells; monocytes; phagocytosis; reactive oxygen species