Data are shown as means SEM (normal group, = 3; control group, = 10; LH2171-administered group, = 10). in the development of EAE, an animal model of MS (Goverman, 2009). The pathogenesis of both MS and EAE is associated with the overexpression of cytokines, including IL-12, IFN-, IL-6, IL-1, IL-21, and IL-23, which function in part to promote the differentiation of effector Th1 and Th17 cells (Bhat and Steinman, 2009; Goverman, 2009; Domingues et al., 2010; Segal, 2010). It has recently been reported that LAB have the Sulcotrione beneficial effects on human health not only to improve the environment of the intestine, but also to PTCH1 have an influence on immune functions. For instance, the intake of SBT2055 increased hemagglutination- inhibition titers against influenza viruses (IFVs) after vaccination as compared to the intake of placebo by healthy volunteers (Nishihira et al., 2016). SBT2055 was found to effectively protect against influenza A virus infection by suppressing viral replication through induction of the expression of antiviral genes in mice (Nakayama et al., 2014; Miyazaki, 2015). Oral administration of KB290 to mice also alleviates clinical symptoms following influenza virus infection by the enhancement of IFN- production and augmentation of IFV-specific IgA production (Waki et al., 2014). Moreover, the beneficial effects of LAB on allergy symptoms have recently been reported. The intake of L-92 reduced subjective symptoms in adult patients with atopic dermatitis (Yamamoto et al., 2016). strain Shirota suppresses systemic anaphylaxis in a food allergy model mice (Shida et al., 2002), and modifies allergen-induced immune responses in allergic rhinitis in human (Ivory et al., 2008). In addition, some reports have demonstrated the effect of LAB on autoimmune diseases (Kato et al., 1998; So et al., 2008; Lavasani et al., 2010; Amdekar et al., 2011; Berer et al., 2011) including MS and EAE, although the specific mechanisms by which LAB exert these alleviative effects remain to be elucidated. Here, we focused on the immune-regulatory activity of the LAB, LH2171. LH2171, a strain of lactobacilli that originates from dairy products, exhibits high protease activity, and is a common starter bacterial strain in the production of a Gouda-type cheese (Sasaki et al., 1996). In our previous study, LH2171 strongly inhibited the proliferation of primary murine immune cells among 41 species of LAB strains, and suppressed the production of LPS-stimulated inflammatory cytokines (IL-6 and IL-1) from the immune cells (Yamashita et al., 2014). Furthermore, administration of LH2171 suppressed the incidence and development of rheumatoid arthritis, one of the major autoimmune diseases, in a murine model (Hosoya et al., 2014; Yamashita et al., 2017). In the present study, to discover a further beneficial property of LH2171 for an excessive immune function, we investigated its alleviating effects in an EAE model. These findings could help to elucidate the mechanisms by which LAB regulate immune function and should contribute to the promotion and development of LAB-based prevention or treatment strategies for immunological diseases. Materials and Methods Bacterial Strain SBT2171 (LH2171) was isolated by Megmilk Snow Brand (Tokyo, Japan). LH2171 was inoculated into Lactobacilli MRS broth (BD Biosciences, San Jose, CA, United States) and cultivated for 16 h at 37C. Following incubation, the cells were harvested by centrifugation at 8,000 for 10 min. The cells Sulcotrione were washed twice with saline and once with distilled water and freeze-dried. Freeze-dried bacterial cells were resuspended in phosphate buffered saline (PBS) at 10 mg/mL and heat-killed at Sulcotrione 80C for 30 min. Induction of EAE and Administration of LH2171 Female SJL/J mice (5 weeks old) were used to assess Sulcotrione the immunosuppressive effect of LH2171 on EAE. The mice (Charles River Japan, Yokohama, Japan) received sterile water and standard chow (Labo MR Stock; Nosan Corporation, Yokohama, Sulcotrione Japan).