Immunostimulatory effects ofBacillus coagulansSANK70258

Abstract

AbstractSpecific intestinal bacteria modulate immunoresponses through various pathways, and several probiotic bacteria have been identified as immunostimulants by screening. In the present study, we evaluated the immunomodulating effects ofBacillus coagulansSANK70258 (B. coagulansSANK70258), a spore-forming and lactic acid-producing bacterium usable as food supplement for human and animals. We found that treatment of mouse splenocytes with γ-ray irradiatedB. coagulansSANK70258 induced high amount of IFN-γ in comparison with 7 kinds of typical lactic acid bacteria. Further analyses using splenocytes revealed that NK cell is a major source of IFN-γ, andB.coagulansSANK70258-induced IFN-γ production was inhibited by neutralization of IL-12 or IL-23, depletion of CD11c+cells, and inhibition of NFκB.B. coagulansSANK70258 also induced release of IFN-γ from activated CD8+T cells, and increased expression of chemokine receptors in CD8+T cells.B. coagulansSANK70258-treatment induced production of cytokines from bone marrow-derived dendritic cells, which is reduced by knockdown ofTlr2andNod2. B. coagulansSANK70258-treatment also induced IgA production from Peyer’s patch cells with high level among tested lactic bacteria. The oral intake of γ-ray irradiatedB. coagulansSANK70258 significantly increased intestinal IgA levels and IgA-expressing B cells in the Peyer’s patch of mice. Taken together, we conclude thatB. coagulansSANK70258 possesses high activity as immunostimulant inducing production of IFN-γ and IgA.