title: Fungal chitin from asthma-associated home environments induces eosinophilic lung infiltration.
abstract: Development of asthma and allergic inflammation involves innate immunity, but the environmental contributions remain incompletely defined. Analysis of dust collected from the homes of asthmatic individuals revealed that the polysaccharide chitin is environmentally widespread and associated with β-glucans, possibly from ubiquitous fungi. Cell wall preparations of Aspergillus isolated from house dust induced robust recruitment of eosinophils into mouse lung, an effect that was attenuated by enzymatic degradation of cell wall chitin and β-glucans. Mice expressing constitutively active acidic mammalian chitinase in the lungs demonstrated a significant reduction in eosinophil infiltration after fungal challenge. Conversely, chitinase inhibition prolonged the duration of tissue eosinophilia. Thus, fungal chitin derived from home environments associated with asthma induces eosinophilic allergic inflammation in the lung, and mammalian chitinases, including acidic mammalian chitinase, limit this process.
authors.affiliation: Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Van Dyken
authors.forename: Daniel
authors.initials: D
authors.lastname: Garcia
authors.forename: Paul
authors.initials: P
authors.lastname: Porter
authors.forename: Xiaozhu
authors.initials: X
authors.lastname: Huang
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Quinlan
authors.forename: Paul D
authors.initials: PD
authors.lastname: Blanc
authors.forename: David B
authors.initials: DB
authors.lastname: Corry
authors.forename: Richard M
authors.initials: RM
authors.lastname: Locksley
mesh_terms: D000818:Animals; D001230:Aspergillus / Q000737:chemistry / Q000276:immunology; D001249:Asthma / Q000276:immunology / Q000382:microbiology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000276:immunology / Q000382:microbiology; D002469:Cell Separation; D002686:Chitin / Q000276:immunology* / Q000302:isolation & purification; D002688:Chitinases / Q000276:immunology; D004391:Dust / Q000032:analysis / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D011657:Pulmonary Eosinophilia / Q000276:immunology* / Q000382:microbiology; D012129:Respiratory Function Tests
chemical_list: D004391:Dust; D002686:Chitin; D002688:Chitinases