title: Immunomodulating and anti-infective effects of a novel strain of Lactobacillus paracasei that strongly induces interleukin-12.
abstract: Several studies have demonstrated that some strains of lactic acid bacteria (LAB) can elicit natural killer (NK) cell activities via interleukin-12 (IL-12) induction and protect against influenza virus (IFV) infection. LAB strains that strongly induce IL-12 are expected to be effective in protecting against IFV infection. In this study, we screened 85 strains for their ability to induce the in vitro production of IL-12, and Lactobacillus paracasei MoLac-1 most strongly induced IL-12. To examine the immunomodulating effects of MoLac-1, we have performed in vitro studies using murine splenocytes. Heat-killed MoLac-1 cells induced IL-12 and interferon-γ (IFN-γ) production by murine splenocytes. Experiments using splenocytes depleted of various cell populations indicated that macrophages might be a major source of MoLac-1-induced IL-12 secretion. Intracellular staining of IFN-γ suggested that MoLac-1 activated NK cells and induced IFN-γ production by NK cells in vitro. Oral administration of heat-killed MoLac-1 increased the proportion of NK cells in spleen, and ameliorated the symptoms of IFV infection in mice. These results suggest that heat-killed MoLac-1 has the potential to modulate innate immunity and is useful for alleviation of the symptoms of IFV infection.
authors: Food Science and Technology Institute, Morinaga Milk Industry Co., Ltd., Zama, Kanagawa, Japan. n-iwabuchi@morinagamilk.co.jp
authors: Noriyuki
authors: N
authors: Iwabuchi
authors: Sumiko
authors: S
authors: Yonezawa
authors: Toshitaka
authors: T
authors: Odamaki
authors: Tomoko
authors: T
authors: Yaeshima
authors: Keiji
authors: K
authors: Iwatsuki
authors: Jin-Zhong
authors: JZ
authors: Xiao
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D007371:Interferon-gamma / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000276:immunology / Q000382:microbiology; D007778:Lactobacillus / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000382:microbiology*; D008264:Macrophages / Q000276:immunology / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D009975:Orthomyxoviridae / Q000276:immunology; D009976:Orthomyxoviridae Infections / Q000473:pathology / Q000628:therapy; D013154:Spleen / Q000276:immunology
chemical_list: D018664:Interleukin-12; D007371:Interferon-gamma