title: Intranasal administration of Lactobacillus rhamnosus GG protects mice from H1N1 influenza virus infection by regulating respiratory immune responses.
abstract: OBJECTIVE
  To investigate whether intranasal Lactobacillus administration protects host animals from influenza virus (IFV) infection by enhancing respiratory immune responses in a mouse model.
  
  
  RESULTS
  After 3 days of intranasal exposure to Lactobacillus rhamnosus GG (LGG), BALB/c mice were infected with IFV A/PR/8/34 (H1N1). Mice treated with LGG showed a lower frequency of accumulated symptoms and a higher survival rate than control mice (P < 0.05). The YAC-1 cell-killing activity of lung cells isolated from mice treated with LGG was significantly greater than those isolated from control mice (P < 0.01). Intranasal administration of LGG significantly increased mRNA expression of interleukin (IL)-1 beta, tumour necrosis factor (TNF) and monocyte chemotactic protein (MCP)-1 (P < 0.01).
  
  
  CONCLUSIONS
  These results suggest that intranasal administration of LGG protects the host animal from IFV infection by enhancing respiratory cell-mediated immune responses following up-regulation of lung natural killer (NK) cell activation.
  
  
  CONCLUSIONS
  We have demonstrated that probiotics might protect host animals from viral infection by stimulating immune responses in the respiratory tract.
authors.affiliation: Technical Research Laboratory, Takanashi Milk Products Co., Ltd.,Yokohama, Kanagawa, Japan.
authors.forename: G
authors.initials: G
authors.lastname: Harata
authors.forename: F
authors.initials: F
authors.lastname: He
authors.forename: N
authors.initials: N
authors.lastname: Hiruta
authors.forename: M
authors.initials: M
authors.lastname: Kawase
authors.forename: A
authors.initials: A
authors.lastname: Kubota
authors.forename: M
authors.initials: M
authors.lastname: Hiramatsu
authors.forename: H
authors.initials: H
authors.lastname: Yausi
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology / Q000502:physiology*; D007251:Influenza, Human / Q000235:genetics / Q000276:immunology* / Q000517:prevention & control* / Q000821:virology; D053583:Interleukin-1beta / Q000235:genetics / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D052201:Lacticaseibacillus rhamnosus / Q000276:immunology*; D008168:Lung / Q000276:immunology / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D012137:Respiratory System / Q000276:immunology* / Q000821:virology
chemical_list: D053583:Interleukin-1beta