title: Activation of Neutrophils via IP3 Pathway Following Exposure to Demodex-Associated Bacterial Proteins.
abstract: Rosacea is a chronic inflammatory condition that predominantly affects the skin of the face. Sera from rosacea patients display elevated reactivity to proteins from a bacterium (Bacillus oleronius) originally isolated from a Demodex mite from a rosacea patient suggesting a possible role for bacteria in the induction and persistence of this condition. This work investigated the ability of B. oleronius proteins to activate neutrophils and demonstrated activation via the IP3 pathway. Activated neutrophils displayed increased levels of IP1 production, F-actin formation, chemotaxis, and production of the pro-inflammatory cytokines IL-1β and IL-6 following stimulation by pure and crude B. oleronius protein preparations (2 μg/ml), respectively. In addition, neutrophils exposed to pure and crude B. oleronius proteins (2 μg/ml) demonstrated increased release of internally stored calcium (Ca(2+)), a hallmark of the IP3 pathway of neutrophil activation. Neutrophils play a significant role in the inflammation associated with rosacea, and this work demonstrates how B. oleronius proteins can induce neutrophil recruitment and activation.
authors.affiliation: Department of Biology, Maynooth University, Co. Kildare, Ireland.
authors.forename: Fred
authors.initials: F
authors.lastname: McMahon
authors.affiliation: Respiratory Research Division, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: Nessa
authors.initials: N
authors.lastname: Banville
authors.affiliation: Respiratory Research Division, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: David A
authors.initials: DA
authors.lastname: Bergin
authors.affiliation: Mabtech AB, Nacka Strand, Sweden.
authors.forename: Christian
authors.initials: C
authors.lastname: Smedman
authors.affiliation: Mabtech AB, Nacka Strand, Sweden.
authors.forename: Staffan
authors.initials: S
authors.lastname: Paulie
authors.affiliation: Respiratory Research Division, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: Emer
authors.initials: E
authors.lastname: Reeves
authors.affiliation: Department of Biology, Maynooth University, Co. Kildare, Ireland. kevin.kavanagh@nuim.ie.
authors.forename: Kevin
authors.initials: K
authors.lastname: Kavanagh
mesh_terms: D000818:Animals; D001407:Bacillus / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D007295:Inositol Phosphates / Q000378:metabolism; D053583:Interleukin-1beta / Q000276:immunology; D015850:Interleukin-6 / Q000276:immunology; D008925:Mites / Q000382:microbiology*; D018375:Neutrophil Activation / Q000276:immunology*; D020556:Neutrophil Infiltration / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology; D012393:Rosacea / Q000276:immunology* / Q000382:microbiology; D012867:Skin / Q000382:microbiology / Q000473:pathology
chemical_list: D001426:Bacterial Proteins; C508585:IL1B protein, human; C508600:IL6 protein, human; D007295:Inositol Phosphates; D053583:Interleukin-1beta; D015850:Interleukin-6; C002647:inositol 1-phosphate; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium
keywords: Bacillus; Demodex; inflammation; neutrophils; rosacea