title: House dust exposure mediates gut microbiome Lactobacillus enrichment and airway immune defense against allergens and virus infection.
abstract: Exposure to dogs in early infancy has been shown to reduce the risk of childhood allergic disease development, and dog ownership is associated with a distinct house dust microbial exposure. Here, we demonstrate, using murine models, that exposure of mice to dog-associated house dust protects against ovalbumin or cockroach allergen-mediated airway pathology. Protected animals exhibited significant reduction in the total number of airway T cells, down-regulation of Th2-related airway responses, as well as mucin secretion. Following dog-associated dust exposure, the cecal microbiome of protected animals was extensively restructured with significant enrichment of, amongst others, Lactobacillus johnsonii. Supplementation of wild-type animals with L. johnsonii protected them against both airway allergen challenge or infection with respiratory syncytial virus. L. johnsonii-mediated protection was associated with significant reductions in the total number and proportion of activated CD11c(+)/CD11b(+) and CD11c(+)/CD8(+) cells, as well as significantly reduced airway Th2 cytokine expression. Our results reveal that exposure to dog-associated household dust results in protection against airway allergen challenge and a distinct gastrointestinal microbiome composition. Moreover, the study identifies L. johnsonii as a pivotal species within the gastrointestinal tract capable of influencing adaptive immunity at remote mucosal surfaces in a manner that is protective against a variety of respiratory insults.
authors.affiliation: Divisions of Gastroenterology and Pulmonary and Critical Care Medicine, University of California, San Francisco, CA 94143.
authors.forename: Kei E
authors.initials: KE
authors.lastname: Fujimura
authors.forename: Tine
authors.initials: T
authors.lastname: Demoor
authors.forename: Marcus
authors.initials: M
authors.lastname: Rauch
authors.forename: Ali A
authors.initials: AA
authors.lastname: Faruqi
authors.forename: Sihyug
authors.initials: S
authors.lastname: Jang
authors.forename: Christine C
authors.initials: CC
authors.lastname: Johnson
authors.forename: Homer A
authors.initials: HA
authors.lastname: Boushey
authors.forename: Edward
authors.initials: E
authors.lastname: Zoratti
authors.forename: Dennis
authors.initials: D
authors.lastname: Ownby
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Lukacs
authors.forename: Susan V
authors.initials: SV
authors.lastname: Lynch
mesh_terms: D000818:Animals; D016535:Bronchial Hyperreactivity / Q000276:immunology* / Q000517:prevention & control; D004285:Dogs; D004391:Dust / Q000276:immunology*; D004781:Environmental Exposure; D005434:Flow Cytometry; D005453:Fluorescence; D041981:Gastrointestinal Tract / Q000382:microbiology*; D007778:Lactobacillus / Q000254:growth & development* / Q000276:immunology; D008168:Lung / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D064307:Microbiota / Q000235:genetics*; D010047:Ovalbumin / Q000276:immunology; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology* / Q000517:prevention & control; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018418:Th2 Cells / Q000276:immunology
chemical_list: D004391:Dust; D010047:Ovalbumin
keywords: Lactobacilliaceae; airway adaptive immunity; gastrointestinal bacterial community; house environment