House dust exposure mediates gut microbiome Lactobacillus enrichment and airway immune defense against allergens and virus infection

作者：Fujimura Kei E; Demoor Tine; Rauch Marcus; Faruqi Ali A; Jang Sihyug; Johnson Christine C; Boushey Homer A; Zoratti Edward; Ownby Dennis; Lukacs Nicholas W^*; Lynch Susan V

来源：Proceedings of the National Academy of Sciences, 2014, 111(2): 805-810.

DOI：10.1073/pnas.1310750111

• house environment
• airway adaptive immunity
• gastrointestinal bacterial community
• Lactobacilliaceae

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.

• 出版日期2014-1-14