title: Control of Pseudomonas aeruginosa skin infections in mice is mast cell-dependent.
abstract: Mast cells (MCs) have recently been shown to be essential for the elicitation of efficient immune responses in murine sepsis. To explore whether MCs also contribute to the control of bacterial skin infections, we studied skin lesions induced by Pseudomonas aeruginosa (PA) in genetically MC-deficient Kit(W)/Kit(W-v) mice, normal Kit(+/+) mice, and MC-reconstituted Kit(W)/Kit(W-v) mice. PA injections resulted in strikingly (>2-fold) larger skin lesions in Kit(W)/Kit(W-v) mice than in Kit(+/+) mice, which exhibited pronounced MC degranulation at infection sites. In addition, neutrophil recruitment following PA injections and bacterial clearance from sites of infection was significantly impaired in Kit(W)/Kit(W-v) mice compared with Kit(+/+) mice. Notably, the adoptive transfer of MCs to the skin of Kit(W)/Kit(W-v) mice before PA infection resulted in normal neutrophil accumulation as well as skin lesions comparable with those in Kit(+/+) mice in both bacterial burden and size. These findings demonstrate for the first time that activated MCs are crucial for the induction of protective innate immune responses to bacterial skin infections.
authors.affiliation: Department of Dermatology and Allergy, Allergie-Centrum-Charité, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Siebenhaar
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Syska
authors.forename: Karsten
authors.initials: K
authors.lastname: Weller
authors.forename: Markus
authors.initials: M
authors.lastname: Magerl
authors.forename: Torsten
authors.initials: T
authors.lastname: Zuberbier
authors.forename: Martin
authors.initials: M
authors.lastname: Metz
authors.forename: Marcus
authors.initials: M
authors.lastname: Maurer
mesh_terms: D000818:Animals; D006801:Humans; D008407:Mast Cells / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009504:Neutrophils / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D011552:Pseudomonas Infections / Q000276:immunology* / Q000473:pathology; D011550:Pseudomonas aeruginosa; D012867:Skin / Q000166:cytology / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D012874:Skin Diseases, Infectious / Q000276:immunology / Q000382:microbiology / Q000473:pathology
chemical_list: D019009:Proto-Oncogene Proteins c-kit