Open AccessHeat‐killed L actobacillus gasseri TMC 0356 protects mice against influenza virus infection by stimulating gut and respiratory immune responses
Author(s) -
Kawase Manabu,
He Fang,
Kubota Akira,
Yoda Kazutoyo,
Miyazawa Kenji,
Hiramatsu Masaru
Publication year - 2012
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2011.00903.x
Subject(s) - lactobacillus gasseri , immune system , biology , immunology , virus , influenza a virus , nasal administration , immunity , microbiology and biotechnology , lactobacillus , genetics , bacteria
This study investigated whether heat‐killed L actobacillus protects host animal against influenza virus infection and stimulates their immunity. Heat‐killed L actobacillus gasseri TMC 0356 was orally administered to BALB /c mice for 19 days; the mice were intranasally infected with F lu A / PR /8/34 ( H1N 1) on day 14, and clinical symptoms were monitored. After 6 days, the mice were sacrificed, and pulmonary virus titres were determined. Splenic activation of natural killer ( NK ) cells and the mRNA expression of cytokines and other immune molecules in the lung and P eyer's patch ( PP ) were analysed. Clinical symptom scores of mice orally fed TMC 0356 ameliorated significantly ( P < 0.01); their pulmonary virus titres decreased significantly compared with those of control mice ( P < 0.05); their mRNA expression of interleukin ( IL )‐12, IL ‐15 and IL ‐21 in PP and the pulmonary mRNA expression of IFN ‐γ, TNF , IL ‐12a, IL ‐12rbl, IL ‐2rb and perforin 1 increased significantly ( P < 0.05). Oral administration of heat‐killed lactobacilli may protect against influenza virus infection by stimulating local and systemic immune responses. Cellular components of lactobacilli may be pivotal in protecting against viral infection by enhancing gut and respiratory immune responses.