The Tox Gene Encodes Two Proteins with Distinct and Shared Roles in Gene Regulation.

Here we report that the murine Tox gene encodes two proteins from a single mRNA, and we investigate the mechanism of production and function of these proteoforms. The annotated thymocyte selection-associated HMG-box protein (TOX) coding sequence is predicted to produce a 526-aa protein (TOXFL). However, Western blots reveal two bands. We found that the lower band consists of an N-terminally truncated variant of TOX (TOXΔN), whereas the slower-migrating band is TOXFL. The TOXΔN proteoform is alternatively translated via leaky ribosomal scanning from an evolutionarily conserved translation initiation site downstream of the annotated translation initiation site. When expressed exogenously from a cDNA in murine CD8 T cells or HEK cells, or endogenously from the murine Tox locus, both forms are translated, although the ratio of TOXFL/TOXΔN significantly varies with cellular context. This includes regulation of proteoform production during development of murine CD4 T cells in the thymus, where the positive selection of CD4+CD8+ cells and subsequent differentiation to CD4+CD8lo transitional and CD4SP cell subsets is associated with both an increase in total TOX protein and increased TOXΔN production relative to TOXFL. Finally, we found that sole expression of TOXFL had a greater effect on gene regulation during chronic stimulation of murine CD8 T cells in culture mimicking exhaustion than did TOXΔN, including uniquely regulated cell cycle and other genes.

PedsQL™ Gastrointestinal Symptoms Scales and Gastrointestinal Worry Scales in pediatric patients with functional and organic gastrointestinal diseases in comparison to healthy controls.

OBJECTIVE: The primary objective was to compare the gastrointestinal (GI) symptoms and worry of pediatric patients with functional GI disorders (FGIDs) and organic GI diseases to healthy controls utilizing the Pediatric Quality of Life Inventory™ (PedsQL™) Gastrointestinal Symptoms and Worry Scales for patient self-reports ages 5-18 years and parent proxy-reports for ages 2-18 years. The secondary objective was to compare FGIDs and organic GI diseases to each other. METHODS: The PedsQL™ Gastrointestinal Symptoms and Worry Scales were completed in a 9-site study by 587 pediatric patients with GI disorders and 685 parents of patients. Patients had physician-diagnosed GI disorders (chronic constipation, functional abdominal pain, irritable bowel syndrome, functional dyspepsia, Crohn's disease, ulcerative colitis, and gastroesophageal reflux disease). Ten Gastrointestinal Symptoms Scales measuring Stomach Pain, Stomach Discomfort When Eating, Food and Drink Limits, Trouble Swallowing, Heartburn and Reflux, Nausea and Vomiting, Gas and Bloating, Constipation, Blood, and Diarrhea were administered along with two Gastrointestinal Worry Scales. Five hundred and thirteen healthy children and 337 parents of healthy children completed the PedsQL™ Gastrointestinal Scales in an Internet panel survey. RESULTS: The PedsQL™ Gastrointestinal Symptoms and Worry Scales distinguished between pediatric patients with FGIDs and organic GI diseases in comparison with healthy controls, supporting known-groups validity. Patients with FGIDs reported more GI symptoms and worry than patients with organic GI diseases. CONCLUSIONS: The PedsQL™ Gastrointestinal Symptoms and Worry Scales may be utilized as common metrics across pediatric patient groups with FGIDs and organic GI diseases and healthy samples to measure GI-specific symptoms in clinical research and practice.

PedsQL gastrointestinal symptoms module: feasibility, reliability, and validity.

OBJECTIVE: The objective of this study was to report on the measurement properties of the Pediatric Quality of Life Inventory (PedsQL) Gastrointestinal Symptoms Module for patients with functional gastrointestinal (GI) disorders (FGIDs) and organic GI diseases, hereafter referred to as "GI disorders," for patient self-report ages between 5 and 18 and parent proxy-report for ages between 2 and 18 years. METHODS: The 74-item PedsQL GI Module and 23-item PedsQL Generic Core Scales were completed in a 9-site study by 584 patients and 682 parents. Patients had physician-diagnosed GI disorders (such as chronic constipation, functional abdominal pain, irritable bowel syndrome, functional dyspepsia, Crohn disease, ulcerative colitis, gastroesophageal reflux disease). RESULTS: Fourteen unidimensional scales were derived measuring stomach pain, stomach discomfort when eating, food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood, diarrhea, worry, medicines, and communication. The PedsQL GI Module Scales evidenced excellent feasibility, excellent reliability for the Total Scale Scores (patient self-report α = 0.97, parent proxy-report α = 0.97), and good-to-excellent reliability for the 14 individual scales (patient self-report α = 0.67-0.94, parent proxy-report α = 0.77-0.95). Intercorrelations with the Generic Core Scales supported construct validity. Individual Symptoms Scales known-groups validity across 7 GI disorders was generally supported. Factor analysis supported the unidimensionality of the individual scales. CONCLUSIONS: The PedsQL GI Module Scales demonstrated acceptable-to-excellent measurement properties and may be used as common metrics to compare GI-specific symptoms in clinical research and practice both within and across patient groups for FGIDs and organic GI diseases.

Heat shock factor 1 drives regulatory T-cell induction to limit murine intestinal inflammation.

The heat shock response is a critical component of the inflammatory cascade that prevents misfolding of new proteins and regulates immune responses. Activation of clusters of differentiation (CD)4+ T cells causes an upregulation of heat shock transcription factor, heat shock factor 1 (HSF1). We hypothesized that HSF1 promotes a pro-regulatory phenotype during inflammation. To validate this hypothesis, we interrogated cell-specific HSF1 knockout mice and HSF1 transgenic mice using in vitro and in vivo techniques. We determined that while HSF1 expression was induced by anti-CD3 stimulation alone, the combination of anti-CD3 and transforming growth factor ß, a vital cytokine for regulatory T cell (Treg) development, resulted in increased activating phosphorylation of HSF1, leading to increased nuclear translocation and binding to heat shock response elements. Using chromatin immunoprecipitation (ChIP), we demonstrate the direct binding of HSF1 to foxp3 in isolated murine CD4+ T cells, which in turn coincided with induction of FoxP3 expression. We defined that conditional knockout of HSF1 decreased development and function of Tregs and overexpression of HSF1 led to increased expression of FoxP3 along with enhanced Treg suppressive function. Adoptive transfer of CD45RBHigh CD4 colitogenic T cells along with HSF1 transgenic CD25+ Tregs prevented intestinal inflammation when wild-type Tregs did not. Finally, overexpression of HSF1 provided enhanced barrier function and protection from murine ileitis. This study demonstrates that HSF1 promotes Treg development and function and may represent both a crucial step in the development of induced regulatory T cells and an exciting target for the treatment of inflammatory diseases with a regulatory T-cell component. SIGNIFICANCE STATEMENT: The heat shock response (HSR) is a canonical stress response triggered by a multitude of stressors, including inflammation. Evidence supports the role of the HSR in regulating inflammation, yet there is a paucity of data on its influence in T cells specifically. Gut homeostasis reflects a balance between regulatory clusters of differentiation (CD)4+ T cells and pro-inflammatory T-helper (Th)17 cells. We show that upon activation within T cells, heat shock factor 1 (HSF1) translocates to the nucleus, and stimulates Treg-specific gene expression. HSF1 deficiency hinders Treg development and function and conversely, HSF1 overexpression enhances Treg development and function. While this work, focuses on HSF1 as a novel therapeutic target for intestinal inflammation, the findings have significance for a broad range of inflammatory conditions.

Markers of Hypoxia Correlate with Histologic and Endoscopic Severity of Colitis in Inflammatory Bowel Disease.

BACKGROUND: Inflammation results in significant shifts in tissue metabolism. Recent studies indicate that inflammation and hypoxia occur concomitantly. We examined whether circulating and tissue markers of hypoxia could serve as surrogate indicators of disease severity in adult and pediatric patients with inflammatory bowel disease (IBD). METHODS: Serum and colonic biopsies were obtained from pediatric subjects with active IBD colitis and adult subjects with active and inactive ulcerative colitis, along with healthy non-colitis controls of all ages. Disease activity was evaluated by endoscopy and histopathology. Levels of serum hypoxia markers (macrophage inflammatory protein-3α [MIP-3α], vascular endothelial growth factor [VEGF], and erythropoietin [EPO]) were measured. RESULTS: Children with active IBD colitis had higher levels of serum MIP-3α and VEGF compared to non-colitis controls (p<0.01 and p<0.05, respectively). In adult subjects with endoscopically active ulcerative colitis, serum MIP-3α and EPO were significantly elevated compared to non-colitis controls (both p<0.01). In parallel, analysis of colon tissue MIP-3α mRNA and protein in pediatric subjects revealed increased expression in those with IBD colitis compared to controls (p<0.05 and p<0.01 for mRNA and protein, respectively). Serum MIP-3α and VEGF significantly increased with histology grade. CONCLUSION: Peripheral blood hypoxia markers may be useful indicators of disease activity for pediatric and adult IBD patients.

Rapid infliximab infusions in pediatric inflammatory bowel disease.

The manufacturer of infliximab recommends infusion over 2 to 3 hours. In 16 children who received 133 standard 2- to 3-hour infusions, followed by fifty 1-hour infusions, chart review revealed a frequency of infusion reactions of 2% with both infusion protocols (3/133 and 1/50). The first reaction with the rapid infusion occurred in a patient who had experienced an identical reaction with the longer infusion, but was mistakenly not premedicated. Our data suggest rapid infusion over 1 hour in selected pediatric patients is safe and cost-effective. Compared with reported adult data, our data suggest similar or lower frequency of adverse events.

Alternative activation generates IL-10 producing type 2 innate lymphoid cells.

Type 2 innate lymphoid cells (ILC2) share cytokine and transcription factor expression with CD4+ Th2 cells, but functional diversity of the ILC2 lineage has yet to be fully explored. Here, we show induction of a molecularly distinct subset of activated lung ILC2, termed ILC210. These cells produce IL-10 and downregulate some pro-inflammatory genes. Signals that generate ILC210 are distinct from those that induce IL-13 production, and gene expression data indicate that an alternative activation pathway leads to the generation of ILC210. In vivo, IL-2 enhances ILC210 generation and is associated with decreased eosinophil recruitment to the lung. Unlike most activated ILC2, the ILC210 population contracts after cessation of stimulation in vivo, with maintenance of a subset that can be recalled by restimulation, analogous to T-cell effector cell and memory cell generation. These data demonstrate the generation of a previously unappreciated IL-10 producing ILC2 effector cell population.

p53 Regulates Progenitor Cell Quiescence and Differentiation in the Airway.

Mechanisms that regulate progenitor cell quiescence and differentiation in slowly replacing tissues are not fully understood. Here, we demonstrate that the tumor suppressor p53 regulates both proliferation and differentiation of progenitors in the airway epithelium. p53 loss decreased ciliated cell differentiation and increased the self-renewal and proliferative capacity of club progenitors, increasing epithelial cell density. p53-deficient progenitors generated a pseudostratified epithelium containing basal-like cells in vitro and putative bronchioalveolar stem cells in vivo. Conversely, an additional copy of p53 increased quiescence and ciliated cell differentiation, highlighting the importance of tight regulation of p53 levels. Using single-cell RNA sequencing, we found that loss of p53 altered the molecular phenotype of progenitors and differentially modulated cell-cycle regulatory genes. Together, these findings reveal that p53 is an essential regulator of progenitor cell behavior, which shapes our understanding of stem cell quiescence during homeostasis and in cancer development.

Esophageal microbiome in eosinophilic esophagitis.

OBJECTIVE: The microbiome has been implicated in the pathogenesis of a number of allergic and inflammatory diseases. The mucosa affected by eosinophilic esophagitis (EoE) is composed of a stratified squamous epithelia and contains intraepithelial eosinophils. To date, no studies have identified the esophageal microbiome in patients with EoE or the impact of treatment on these organisms. The aim of this study was to identify the esophageal microbiome in EoE and determine whether treatments change this profile. We hypothesized that clinically relevant alterations in bacterial populations are present in different forms of esophagitis. DESIGN: In this prospective study, secretions from the esophageal mucosa were collected from children and adults with EoE, Gastroesophageal Reflux Disease (GERD) and normal mucosa using the Esophageal String Test (EST). Bacterial load was determined using quantitative PCR. Bacterial communities, determined by 16S rRNA gene amplification and 454 pyrosequencing, were compared between health and disease. RESULTS: Samples from a total of 70 children and adult subjects were examined. Bacterial load was increased in both EoE and GERD relative to normal subjects. In subjects with EoE, load was increased regardless of treatment status or degree of mucosal eosinophilia compared with normal. Haemophilus was significantly increased in untreated EoE subjects as compared with normal subjects. Streptococcus was decreased in GERD subjects on proton pump inhibition as compared with normal subjects. CONCLUSIONS: Diseases associated with mucosal eosinophilia are characterized by a different microbiome from that found in the normal mucosa. Microbiota may contribute to esophageal inflammation in EoE and GERD.

Targeted inhibition of heat shock protein 90 suppresses tumor necrosis factor-α and ameliorates murine intestinal inflammation.

Inflammatory bowel diseases are chronic intestinal inflammatory diseases thought to reflect a dysregulated immune response. Although antibody-based inhibition of tumor necrosis factor-α (TNF-α) has provided relief to many inflammatory bowel diseases patients, these therapies are either ineffective in a patient subset or lose their efficacy over time, leaving an unmet need for alternatives. Given the critical role of the heat shock response in regulating inflammation, this study proposed to define the impact of selective inhibition of heat shock protein 90 (HSP90) on intestinal inflammation. Using multiple preclinical mouse models of inflammatory bowel diseases, we demonstrate a potent anti-inflammatory effect of selective inhibition of the HSP90 C-terminal ATPase using the compound novobiocin. Novobiocin-attenuated dextran sulfate sodium-induced colitis and CD45RB adoptive-transfer colitis through the suppression of inflammatory cytokine secretion, including TNF-α. In vitro assays demonstrate that CD4 T cells treated with novobiocin produced significantly less TNF-α measured by intracellular cytokine staining and by enzyme-linked immunosorbent assay. This corresponded to significantly decreased nuclear p65 translocation by Western blot and a decrease in nuclear factor-κB luciferase activity in Jurkat T cells. Finally, to verify the anti-TNF action of novobiocin, 20-week-old TNFΔ mice were treated for 2 weeks with subcutaneous administration of novobiocin. This model has high levels of circulating TNF-α and exhibits spontaneous transmural segmental ileitis. Novobiocin treatment significantly reduced inflammatory cell infiltrate in the ileal lamina propria. HSP90 inhibition with novobiocin offers a novel method of inflammatory cytokine suppression without potential for the development of tolerance that limits current antibody-based methods.