title: CD11c+ cells are required for antigen-induced increase of mast cells in the lung.
abstract: Patients with allergic asthma have more lung mast cells, which likely worsens the symptoms. In experimental asthma, CD11c(+) cells have to be present during the challenge phase for several features of allergic inflammation to occur. Whether CD11c(+) cells play a role for Ag-induced increases of lung mast cells is unknown. In this study, we used diphtheria toxin treatment of sensitized CD11c-diphtheria toxin receptor transgenic mice to deplete CD11c(+) cells. We demonstrate that recruitment of mast cell progenitors to the lung is substantially reduced when CD11c(+) cells are depleted during the challenge phase. This correlated with an impaired induction of endothelial VCAM-1 and led to a significantly reduced number of mature mast cells 1 wk after challenge. Collectively, these data suggest that Ag challenge stimulates CD11c(+) cells to produce cytokines and/or chemokines required for VCAM-1 upregulation on the lung endothelium, which in turn is crucial for the Ag-induced mast cell progenitor recruitment and the increase in mast cell numbers.
authors.affiliation: Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 23 Uppsala, Sweden.
authors.forename: Joakim S
authors.initials: JS
authors.lastname: Dahlin
authors.forename: Ricardo
authors.initials: R
authors.lastname: Feinstein
authors.forename: Yue
authors.initials: Y
authors.lastname: Cui
authors.forename: Birgitta
authors.initials: B
authors.lastname: Heyman
authors.forename: Jenny
authors.initials: J
authors.lastname: Hallgren
mesh_terms: D000818:Animals; D039521:CD11c Antigen / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D002465:Cell Movement / Q000276:immunology*; D018925:Chemokines / Q000096:biosynthesis / Q000502:physiology; D004167:Diphtheria Toxin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008168:Lung / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D008212:Lymphocyte Depletion; D008297:Male; D008407:Mast Cells / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D020545:Respiratory Mucosa / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology*; D019010:Vascular Cell Adhesion Molecule-1 / Q000096:biosynthesis
chemical_list: D039521:CD11c Antigen; D018925:Chemokines; D004167:Diphtheria Toxin; D019010:Vascular Cell Adhesion Molecule-1