Plasmacytoid dendritic cell is getting a lot of attention as a “commander in chief” which regulates anti-viral immune system. In this study, we screened for lactic acid bacteria which are able to stimulate plasmacytoid dendritic cell. Lactococcus lactis subsp. lactis JCM 5805 was selected by the screening using murine bone marrow-derived plasmacytoid dendritic cell. It was suggested that the strain JCM 5805 was recognized by plasmacytoid dendritic cell and TLR9-dependent activation was induced by its DNA. Effects of L. lactis JCM 5805 on human pDC are also introduced.

View full abstract

Probiotics exhibit beneficial effects on human health. We examined the effect of 59 strains of heat-killed Lactobacillus brevis on their ability to skew Th1/Th2 balance toward Th1 dominant. L. brevis SBC8803 was selected as a potent inhibitor of IgE production. We had previously demonstrated that this strain showed anti-allergic property, prevention of alcoholic liver disease and fortification of intestinal barrier function. In this study, we aimed to isolate the cytoprotective compound from this strain. A culture supernatant of SBC8803 was fractionated by ammonium sulfate precipitation, DEAE anion exchange chromatography, gel filtration, and HPLC, and then targeted components were screened by evaluating cytoprotective HSP27 expression from Caco2/bbe cells. Finally, we identified that the HSP27-inducible fraction was polyphosphate (poly P). Then, poly P was synthesized by polyphosphate kinase. The synthesized poly P significantly suppressed the oxidant-induced intestinal permeability in the mouse small intestine and pharmacological inhibitors of p38 MAPK and integrins counteract its protective effect. Daily intrarectal administration of polyphosphate (10μg) improved the survival rate in 4% sodium dextran sulfate-administered mice. Selection of high poly P producing strain and unravelling the mechanism of its poly P production will lead to therapeutic development to intestinal barrier related various gut disorder.

View full abstract

Next-generation sequencing (NGS) technology is a fundamental means of studying genome, transcriptome, and microbiome. We can analyze NGS data of bacteria such as Lactobacillus using laptop computer nowadays. However, for many non-bioinformaticians, it is difficult to construct an environment for analyzing NGS data. In this review, we describe educational programs, websites, application softwares, programming languages, and webtools. An example of genome analysis of Lactobacillus casei 12A is also provided.

View full abstract