Genome-based phylogenetic analysis of the <i>L. casei</i> group.

<p>(<b>A</b>) Phylogenetic relationships between the genomes of sequenced lactobacilli inferred from 34 concatenated ribosomal protein amino acid sequences. The scale bar represents an evolutionary distance. Sequences were aligned with ClustalW with a bootstrap trial of 1,000 and bootstrap values (%) are indicated at the nodes. An unrooted tree was generated using NJplot. The chromosome size is shown in parentheses. (<b>B</b>) Three-way comparisons between <i>L. casei</i> ATCC 393 with <i>L. rhamnosus</i> ATCC 53103 and <i>L. paracasei</i> ATCC 334. The 2,191 genes shared by the three strains were classified into three categories on the basis of the BLAST score ratio analysis <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0075073#pone.0075073-Rasko1" target="_blank">[23]</a>. (<b>C</b>) Venn diagram comparing the gene inventories of four strains of the <i>L. casei</i> group. Data resulted from reciprocal BLASTP analysis. The numbers of shared and unique genes are shown.</p

Circular representations of the chromosomes of <i>L. rhamnosus</i> ATCC 53103, <i>L. paracasei</i> JCM 8130, and <i>L. casei</i> ATCC 393.

<p>From the outside: circles 1 and 2 of the chromosome show the positions of protein-coding genes on the positive and negative strands, respectively. Circle 3 shows the positions of protein-coding genes that are shared among the 10 completely sequenced genomes of the <i>L. casei</i> group. Circle 4 shows the positions of tRNA genes (orange) and rRNA genes (blue). Circle 5 shows a plot of GC skew [(G − C)/(G+C); orange indicates values >0; blue indicates values <0]. Circle 6 shows a plot of G+C content (outward: higher values than the average). The genomic islands in each strain are boxed: regions including carbohydrate utilization gene cluster (pink), prophage-like regions (green), and the others (blue).</p

Genomic islands in <i>L. rhamnosus</i> ATCC 53103, <i>L. paracasei</i> JCM 8130, and <i>L. casei</i> ATCC 393.

<p>Genomic islands in <i>L. rhamnosus</i> ATCC 53103, <i>L. paracasei</i> JCM 8130, and <i>L. casei</i> ATCC 393.</p

<i>Bifidobacterium longum</i> Alleviates Dextran Sulfate Sodium-Induced Colitis by Suppressing IL-17A Response: Involvement of Intestinal Epithelial Costimulatory Molecules

<div><p>Although some bacterial strains show potential to prevent colitis, their mechanisms are not fully understood. Here, we investigated the anti-colitic mechanisms of <i>Bifidobacterium longum</i> subsp. <i>infantis</i> JCM 1222^T, focusing on the relationship between interleukin (IL)-17A secreting CD4⁺ T cells and intestinal epithelial costimulatory molecules in mice. Oral administration of JCM 1222^T to mice alleviated dextran sulfate sodium (DSS)-induced acute colitis. The expression of type 1 helper T (Th1)- and IL-17 producing helper T (Th17)-specific cytokines and transcriptional factors was suppressed by JCM 1222^T treatment. Intestinal epithelial cells (IECs) from colitic mice induced IL-17A production from CD4⁺ T cells in a cell-cell contact-dependent manner, and this was suppressed by oral treatment with JCM 1222^T. Using blocking antibodies for costimulatory molecules, we revealed that epithelial costimulatory molecules including CD80 and CD40, which were highly expressed in IECs from colitic mice, were involved in IEC-induced IL-17A response. Treatment of mice and intestinal epithelial cell line Colon-26 cells with JCM 1222^T decreased the expression of CD80 and CD40. Collectively, these data indicate that JCM 1222^T negatively regulate epithelial costimulatory molecules, and this effect might be attributed, at least in part, to suppression of IL-17A in DSS-induced colitis.</p> </div

Oral treatment of <i>B. longum</i> JCM 1222^T (<i>B.l</i>) suppresses Th17-specific cytokines and transcription factors.

<p>(a) Cytokine production from colonic tissue culture was measured by ELISA. (b) mRNA expression of transcription factors in LPL was analyzed by quantitative PCR. Levels of mRNA were normalized to β-actin mRNA, and expressed relative to control mice. (c) LPL was analyzed for cytokine-expression profiles by intracellular cytokine staining. The frequency of CD4⁺ T cells expressing the indicated cytokines is shown (n = 3-6). The data are representative of two experiments. Results are expressed as means ± standard error (n = 4). ^*<i>p</i><0.05 and ^**<i>p</i><0.01 versus control mice (Control); ^#<i>p</i><0.05 versus DSS-treated mice (DSS). </p

<i>B. longum</i> JCM 1222^T (B.l) suppresses the expression of costimulatory molecules in Colon-26 cells.

<p>(a) mRNA expression of CD80 and CD40 was analyzed by quantitative real-time PCR in Colon-26 cells after stimulation with IFN-γ. Levels of mRNA were normalized to β-actin mRNA, and expressed relative to before stimulation (0 h). Results are expressed as means ± standard error (n = 4). ^*<i>p</i><0.05 and ^**<i>p</i><0.01 versus before stimulation (0 h). (b) Colon-26 cells were pre-incubated with <i>B. longum</i> JCM 1222^T, and then treated with penicillin and streptomycin and incubated with IFN-γ. Messenger RNA expression of CD80 and CD40 was analyzed after stimulation with IFN-γ for 6 and 72 h, respectively. The data are representative of three experiments. (c) Colon-26 cells were incubated with <i>B. longum</i> JCM 1222^T and IFN-γ. Cell surface protein expression of CD80 and CD40 was analyzed by flow cytometry after stimulation with IFN-γ. Debris was gated out by forward and side scatter. Histograms show a representative experiment (specific antibody stains are shown in filled histograms, and isotype control antibody stains are shown in open histograms) and bar figures are representative of two experiments. ^**<i>p</i><0.01 versus non-treated cells (Control); ^#<i>p</i><0.05 and ^##<i>p</i><0.01 versus IFN-γ-stimulated cells.</p

Oral treatment of <i>B. longum</i> JCM 1222^T (B.l) alleviates DSS-induced acute colitis.

<p>Mice were monitored daily for weight loss (a) and DAI (b). On day 5, the entire colon was removed (c), and the length was measured (d). The data are representative of four experiments. Colonic tissue sections were stained with hematoxylin-eosin for histological examination (e). The data are representative of two experiments. Scale bars represent 100 μm. The data are Results are expressed as means ± standard error (n = 4). ^**<i>p</i><0.01 versus control mice (Control); ^#<i>p</i><0.05 and ^##<i>p</i><0.01 versus DSS-treated mice (DSS). </p

Gene clusters encoding cell surface proteins in <i>L. rhamnosus</i> ATCC 53103.

<p>(<b>A</b>) WxL clusters. (<b>B</b>) Putative glycosylated cell-surface protein clusters. Genes and their orientations are depicted with arrows. Gray bars indicate orthologous regions between <i>L. rhamnosus</i> ATCC 53103 and <i>L. paracasei</i> ATCC 334.</p

Abundance of genes related to carbohydrate transport and metabolism in <i>L. rhamnosus</i> ATCC 53103.

<p>(<b>A</b>) Comparative analysis by functional categories of the gene repertoires of sequenced intestinal lactobacilli. The number of genes assigned to COG category G in each genome is shown. (<b>B</b>) Carbohydrate utilization gene clusters of <i>L. rhamnosus</i> ATCC 53103. Genes and their orientations are depicted with arrows. Regions -5 and -6 are compared with the corresponding genomic locations in <i>L. rhamnosus</i> Lc 705. Gray bars indicate orthologous regions.</p

Putative cell surface adherence proteins of <i>L. rhamnosus</i> ATCC 53103.

*<p>‘+’ indicates that the orthologous gene is present, and ‘−’ indicates that the orthologous gene is absent.</p