Targeting of MIST to Src-family kinases via SKAP55–SLAP-130 adaptor complex in mast cells11The rat SKAP55 cDNA nucleotide sequence has been deposited in DDBJ database under accession number AB092812.

AbstractMIST (mast cell immunoreceptor signal transducer; also termed Clnk) is an adaptor protein structurally related to SLP-76-family hematopoietic cell-specific adaptor proteins. We demonstrate here that two major MIST-associated phosphoproteins expressed in mast cell lines are SLAP-130 and SKAP55, adaptors known to interact with the Src-homology (SH) 2 domain of Src-family protein tyrosine kinases (PTKs). MIST directly associated with SLAP-130 via its SH2 domain, and collaboration of SLAP-130 with SKAP55 was required for the recruitment of MIST to Lyn. Furthermore, MIST was preferentially recruited to Fyn rather than Lyn, which is regulated by higher affinity binding of SLAP-130 and SKAP55 with the Fyn-SH2 domain than the Lyn-SH2 domain. Our results suggest that the MIST–SLAP-130–SKAP55 adaptor complex functions downstream of high-affinity IgE receptor-associated Src-PTKs in mast cells

Role of SDF1/CXCR4 Interaction in Experimental Hemiplegic Models with Neural Cell Transplantation

Much attention has been focused on neural cell transplantation because of its promising clinical applications. We have reported that embryonic stem (ES) cell derived neural stem/progenitor cell transplantation significantly improved motor functions in a hemiplegic mouse model. It is important to understand the molecular mechanisms governing neural regeneration of the damaged motor cortex after the transplantation. Recent investigations disclosed that chemokines participated in the regulation of migration and maturation of neural cell grafts. In this review, we summarize the involvement of inflammatory chemokines including stromal cell derived factor 1 (SDF1) in neural regeneration after ES cell derived neural stem/progenitor cell transplantation in mouse stroke models

Bifidobacteria Abundance-Featured Gut Microbiota Compositional Change in Patients with Behcet's Disease.

Gut microbiota compositional alteration may have an association with immune dysfunction in patients with Behcet's disease (BD). We conducted a fecal metagenomic analysis of BD patients. We analyzed fecal microbiota obtained from 12 patients with BD and 12 normal individuals by sequencing of 16S ribosomal RNA gene. We compared the relative abundance of bacterial taxa. Direct comparison of the relative abundance of bacterial taxa demonstrated that the genera Bifidobacterium and Eggerthella increased significantly and the genera Megamonas and Prevotella decreased significantly in BD patients compared with normal individuals. A linear discriminant analysis of bacterial taxa showed that the phylum Actinobacteria, including Bifidobacterium, and the family Lactobacillaceae exhibited larger positive effect sizes than other bacteria in patients with BD. The phylum Firmicutes and the class Clostridia had large effect sizes in normal individuals. There was no significant difference in annotated species numbers (as numbers of operational taxonomic unit; OTU) and bacterial diversity of each sample (alpha diversity) between BD patients and normal individuals. We next assigned each sample to a position using three axes by principal coordinates analysis of the OTU table. The two groups had a significant distance as beta diversity in the 3-axis space. Fecal sIgA concentrations increased significantly in BD patients but did not correlate with any bacterial taxonomic abundance. These data suggest that the compositional changes of gut microbes may be one type of dysbiosis (unfavorable microbiota alteration) in patients with BD. The dysbiosis may have an association with the pathophysiology of BD

Propionate-producing bacteria in the intestine may associate with skewed responses of IL10-producing regulatory T cells in patients with relapsing polychondritis.

Relapsing polychondritis (RP) is an inflammatory disease of unknown causes, characterized by recurrent inflammation in cartilaginous tissues of the whole body. Recently, researchers have reported that, in mouse experiments, altered gut microbe-dependent T cell differentiation occurred in gut associated lymphoid tissues. Here, we investigated whether gut microbe alteration existed, and if so, the alteration affected peripheral T cell differentiation in patients with RP. In an analysis of gut microbiota, we found increased annotated species numbers in RP patients compared with normal individuals. In the RP gut microbiota, we observed several predominant species, namely Veillonella parvula, Bacteroides eggerthii, Bacteroides fragilis, Ruminococcus bromii, and Eubacterium dolichum, all species of which were reported to associate with propionate production in human intestine. Propionate is a short-chain fatty acid and is suggested to associate with interleukin (IL)10-producing regulatory T (Treg) cell differentiation in gut associated lymphoid tissues. IL10 gene expressions were moderately higher in freshly isolated peripheral blood mononuclear cells (PBMC) of RP patients than those of normal individuals. Six hours after the initiation of the cell culture, regardless of the presence and absence of mitogen stimulation, IL10 gene expressions were significantly lower in RP patients than those in normal individuals. It is well known that PBMC of patients with autoimmune and inflammatory diseases show hyporesponsiveness to mitogen stimulation. We suggest that, in RP patients, continuous stimulation of intestinal T cells by excessive propionate leads to the spontaneous IL10 production and a subsequent refractory period of T cells in patients with RP. The hyporesponsiveness of Treg cells upon activation may associate with inflammatory cytokine production of PBMC and subsequently relate to chondritis in RP patients

Comparison of the taxa showing different abundance values in BD patients and normal individuals.

<p>We analyzed the metagenomic data of bacterial taxa using LEfSe to detect major differences between BD patients (BD) and normal individuals (NI). The LEfSe provides us with cladograms of six-level (from kingdom to genus). Significantly enriched bacterial taxa in samples obtained from BD patients were demonstrated using red circles and shadings. Significantly enriched bacterial taxa in samples obtained from normal individuals were demonstrated using green circles and shadings. In patients with BD, the phylum <i>Actinobacteria</i>, namely the classes <i>Actinobacteria</i> and <i>Coriobacteria</i>, the orders <i>Bifidobacteriales</i> and <i>Coriobacteriales</i>, and the genera <i>Bifidobacterium</i>, <i>Eggerthella</i> and <i>Atopobium</i> had large effect sizes. The phylum <i>Firmicutes</i>, the class <i>Clostridia</i>, the order <i>Clostridiales</i>, the family <i>Veillonellaceae</i>, and the genera <i>Megamonas</i> and <i>Phascolarctobacterium</i> had large effect sizes in normal individuals.</p

Demographical and clinical characteristics of patients with Behcet’s disease and normal individuals.

<p>Demographical and clinical characteristics of patients with Behcet’s disease and normal individuals.</p

Direct comparison of bacterial taxonomic abundance between BD patients and normal individuals.

<p>We compared directly the relative abundance (expressed as parts per unit) between BD patients (BD) and normal individuals (NI). We conducted Wilcoxon rank sum test for the differences in every taxon, followed by Tukey’s honestly significant difference (HSD) test. We considered that bacterial taxa increased or decreased significantly in patients with BD as compared with those in normal individuals by fulfilling the following criteria simultaneously; #1: bacterial taxa showing significant differences by the Wilcoxon rank sum test, and #2: bacterial taxa showing positive Tukey’s HSD values. We found that there were significant differences in 11 bacterial taxa (also shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153746#pone.0153746.g002" target="_blank">Fig 2</a> with asterisks). “p__”, “c__”, “o__”, “f__” and “g__” indicate phylum, class, order, family and genus, respectively. Relative abundance of bacterial taxa in BD patients and normal individuals were displayed with dot plots. A box-plot and a mean level (green line) of each group of BD patients and normal individuals were indicated.</p

Comparison of fecal secretory IgA concentrations and bacterial diversity between BD patients and normal individuals.

<p>(A) We evaluated the secretory IgA (sIgA) concentrations of fecal supernatants using ELISA. We observed a significant increase in sIgA concentrations of patients with BD (BD) compared with those of normal individuals (NI). (B) We counted OTU numbers (annotated species numbers) and estimated alpha diversity score (Chao 1 and Shannon indexes) of each sample. We compared the titers between BD patients and normal individuals. We did not find significant differences in the parameters between BD patients and normal individuals. These biological parameters of BD patients and normal individuals were displayed with dot plots. A box-plot and a mean level (green line) of each group of BD patients and normal individuals were indicated. (C) We estimated beta diversity between BD patients and normal individuals using PCoA of QIIME software with linear conversion formulas. We visualized the PCoA plots in a three dimensional structure where three axes and each contribution ratio (principal coordinate, PC1–3, %) were depicted. We calculated the distance between the distribution of BD patients and that of normal individuals using a two-sided Student's two-sample t-test as an exploratory analysis. We obtained a significant P value of the test of beta diversity between BD patients and normal individuals.</p