No abstract

No abstract

Th17 cells, which all express the chemokine receptor CCR6, are implicated in many immune-mediated disorders such as psoriasis and multiple sclerosis. We found that expression levels of CCR6 on human effector/memory CD4+ T cells reflect a continuum of Th17 differentiation. By evaluating the transcriptome in cells with increasing CCR6, we detected progressive up-regulation of ZBTB16, which encodes the BTB-ZF transcription factor PLZF. Using ChIP for modified histones, p300, and PLZF, we identified enhancer-like sites at −9/−10 kb and −13/−14 kb from the upstream transcription start site of CCR6 that bind PLZF in CCR6+ cells. For Th cells from adult blood, both in the CCR6+ memory population and in naïve cells activated ex vivo, knockdown of ZBTB16 down-regulated CCR6 and other Th17-associated genes. ZBTB16 and RORC (which encodes the “master regulator” RORγt) cross-regulate each other, and PLZF binds at the RORC promoter in CCR6+ cells. In naive Th cells from cord blood, ZBTB16 expression was confined to the CD161+ cells, which are the Th17 cell precursors. ZBTB16 was not expressed in mouse Th17 cells and Th17 cells could be made from luxoid mice, which harbor an inactivating mutation in Zbtb16. These studies demonstrate a role for PLZF as an activator of transcription important both for Th17 differentiation and the maintenance of the Th17 phenotype in human cells, expand the role of PLZF as a critical regulator in the human adaptive immune system, and identify a novel, essential element in a regulatory network that is of significant therapeutic interest.

Background: Wilson’s disease (WD) is a genetic disorder involving the metabolism of copper. WD patients exhibit a wide range of disease phenotypes, including Kayser-Fleischer rings in the cornea, predominant progressive hepatic disease, neurological diseases, and/or psychiatric illnesses, among others. Patients with exon12 mutations of the ATP7B gene have progressive hepatic disease. An ATP7B gene that lacks exon12 retains 80% of its copper transport activities, suggesting that alternative splicing of ATP7B gene may provide alternative therapeutic ways for patients with inherited sequence variants and mutations of this gene. Purpose: We aimed to search for possible Chinese herbs and related compounds for modulating ATP7B premRNA splicing.Methods: We used an ATP7B exon11-12-13 mini-gene vector as a model and screened 18 Chinese herbal extracts and four compounds from Schizonepeta to determine their effects on ATP7B pre-mRNA splicing in vitro.Results: We found that Schizonepeta demonstrated the greatest potential for alternative splicing activity. Specifically, we found that p-coumaric acid from this herb enhanced ATP7B exon12 exclusion through the down-regulation of heterogeneous ribonucleoprotein (hnRNP) A1 protein expressions.Conclusion: These results suggest that there are herbs or herb-related compounds that could modify the alternative splicing of the ATP7B gene via a mechanism that regulates pre-mRNA splicing.

Historically, cholera outbreaks have been linked to V. cholerae O1 serogroup strains or its derivatives of the O37 and O139 serogroups. A genomic study on the 2010 Haiti cholera outbreak strains highlighted the putative role of non O1/non-O139 V. cholerae in causing cholera and the lack of genomic sequences of such strains from around the world. Here we address these gaps by scanning a global collection of V. cholerae strains as a first step towards understanding the population genetic diversity and epidemic potential of non O1/non-O139 strains. Whole Genome Mapping (Optical Mapping) based bar coding produces a high resolution, ordered restriction map, depicting a complete view of the unique chromosomal architecture of an organism. To assess the genomic diversity of non-O1/non-O139 V. cholerae, we applied a Whole Genome Mapping strategy on a well-defined and geographically and temporally diverse strain collection, the Sakazaki serogroup type strains. Whole Genome Map data on 91 of the 206 serogroup type strains support the hypothesis that V. cholerae has an unprecedented genetic and genomic structural diversity. Interestingly, we discovered chromosomal fusions in two unusual strains that possess a single chromosome instead of the two chromosomes usually found in V. cholerae. We also found pervasive chromosomal rearrangements such as duplications and indels in many strains. The majority of Vibrio genome sequences currently in public databases are unfinished draft sequences. The Whole Genome Mapping approach presented here enables rapid screening of large strain collections to capture genomic complexities that would not have been otherwise revealed by unfinished draft genome sequencing and thus aids in assembling and finishing draft sequences of complex genomes. Furthermore, Whole Genome Mapping allows for prediction of novel V. cholerae non-O1/non-O139 strains that may have the potential to cause future cholera outbreaks.

Many mediators and regulators of extravasation by bona fide human memory-phenotype T cells remain undefined. Mucosal-associated invariant T (MAIT) cells are innate-like, antibacterial cells that we found excelled at crossing inflamed endothelium. They displayed abundant selectin ligands, with high expression of FUT7 and ST3GAL4, and expressed CCR6, CCR5, and CCR2, which played non-redundant roles in trafficking on activated endothelial cells. MAIT cells selectively expressed CCAAT/enhancer-binding protein delta (C/EBPδ). Knockdown of C/EBPδ diminished expression of FUT7, ST3GAL4 and CCR6, decreasing MAIT cell rolling and arrest, and consequently the cells’ ability to cross an endothelial monolayer in vitro and extravasate in mice. Nonetheless, knockdown of C/EBPδ did not affect CCR2, which was important for the step of transendothelial migration. Thus, MAIT cells demonstrate a program for extravasastion that includes, in part, C/EBPδ and C/EBPδ-regulated genes, and that could be used to enhance, or targeted to inhibit T cell recruitment into inflamed tissue.

Kawasaki disease (KD) is an acute, inflammatory, and self-limited vasculitis affecting infants and young children. Coronary artery aneurysm (CAA) formation is the major complication of KD and the leading cause of acquired cardiovascular disease among children. To identify susceptible loci that might predispose patients with KD to CAA formation, a genome-wide association screen was performed in a Taiwanese KD cohort. Patients with both KD and CAA had longer fever duration and delayed intravenous immunoglobulin treatment time. After adjusting for these factors, 100 susceptibility loci were identified. Four genes were identified from a single cluster of 35 using the Ingenuity Pathway Analysis (IPA) Knowledge Base. Silencing KCNQ5, PLCB1, PLCB4, and PLCL1 inhibited the effect of lipopolysaccharide-induced endothelial cell inflammation with varying degrees of proinflammatory cytokine expression. PLCB1 showed the most significant inhibition. Endothelial cell inflammation was also inhibited by using a phospholipase C (PLC) inhibitor. The single nucleotide polymorphism rs6140791 was identified between PLCB4 and PLCB1. Plasma PLC levels were higher in patients with KD and CC+CG rs6140791genotypes, and these genotypes were more prevalent in patients with KD who also had CAA. Our results suggest that polymorphism of the PLCB4/B1 genes might be involved in the CAA pathogenesis of KD.

No abstract