title: Heat-killed Lactobacillus gasseri TMC0356 protects mice against influenza virus infection by stimulating gut and respiratory immune responses.
abstract: This study investigated whether heat-killed Lactobacillus protects host animal against influenza virus infection and stimulates their immunity. Heat-killed Lactobacillus gasseri TMC0356 was orally administered to BALB/c mice for 19 days; the mice were intranasally infected with Flu A/PR/8/34 (H1N1) 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 Peyer's patch (PP) were analysed. Clinical symptom scores of mice orally fed TMC0356 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.
authors.affiliation: Technical Research Laboratory, Takanashi Milk Products Co., Ltd, Yokohama, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kawase
authors.forename: Fang
authors.initials: F
authors.lastname: He
authors.forename: Akira
authors.initials: A
authors.lastname: Kubota
authors.forename: Kazutoyo
authors.initials: K
authors.lastname: Yoda
authors.forename: Kenji
authors.initials: K
authors.lastname: Miyazawa
authors.forename: Masaru
authors.initials: M
authors.lastname: Hiramatsu
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006651:Histocytochemistry; D053118:Influenza A Virus, H1N1 Subtype; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology; D007778:Lactobacillus; D008168:Lung / Q000276:immunology* / Q000382:microbiology / Q000473:pathology / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000276:immunology / Q000517:prevention & control*; D010581:Peyer's Patches / Q000821:virology; D019936:Probiotics / Q000008:administration & dosage*; D013154:Spleen / Q000166:cytology / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D019562:Viral Load / Q000187:drug effects
chemical_list: D016207:Cytokines