Kita, H

INTRODUCTION: We aimed to assess the diagnostic utility of eosinophil peroxidase (EPX) staining on Cytosponge (CS) samples in eosinophilic esophagitis (EoE). METHODS: Esophageal biopsy (BX) samples from adult subjects with EoE were assessed using peak eosinophils per high-power field (eos/hpf), EPX, and the EoE histologic scoring system. EPX staining and eos/hpf were compared (BX vs CS). RESULTS: CS EPX positivity correlated with eos/hpf (CS [ r = 0.82, P < 0.0001]; BX [ r = 0.65, P < 0.0001]) and EoE histologic scoring system (grade [ r = 0.62, P < 0.00001]; stage [ r = 0.61, P < 0.0001]). CS EPX identified subjects with active EoE (area under the curve = 0.86, P < 0.0001). DISCUSSION: The correlation of CS EPX with eosinophilic inflammation and histologic disease severity supports its diagnostic utility in EoE.

Abstract Background Risk factors for the pathogenesis of chronic rhinosinusitis (CRS) remain largely undetermined, which is likely due to the heterogeneity of the disease. White blood cell counts have been largely unexplored as a risk factor for CRS even though different types of white blood cells are involved in the inflammatory process of CRS. Objective To investigate causal associations between different types of white blood cells on risk of CRS utilizing a Mendelian randomization (MR) analysis. Methods A two-sample MR analysis was performed using respective GWAS summary statistics for the exposure traits (neutrophil count, eosinophil count, basophil count, lymphocyte count, and monocyte count) and outcome trait (CRS). For the exposure traits, the European Bioinformatics Institute database of complete GWAS summary data was used. For the outcome trait, summary statistics for CRS GWAS were obtained from FinnGen. Primary analysis for MR was performed using inverse-variance weighted two-sample MR. Sensitivity analyses included weighted median, MR-Egger, and MR-PRESSO (raw and outlier-corrected). Results Eosinophils were associated with CRS (OR = 1.55 [95%CI 1.38,1.73]; p = 4.3E-14). Eosinophil results were similar across additional MR methods. MR results did not demonstrate significant causal relationships between neutrophils, lymphocytes, monocytes, or basophils with CRS. No significant pleiotropic bias was observed. Conclusions In a two-sample MR analysis, a potential causal link between blood eosinophil counts and CRS has been demonstrated. In addition, causal relationships between blood counts among other white blood cell types and CRS were not found. Further studies involving genetic variation in CRS are needed to corroborate genetic causal effects for CRS.

AbstractBackgroundEosinophilic esophagitis (EoE) is a chronic allergic disease associated with type 2 inflammation and epithelial barrier dysfunction. The etiology is unknown, however, genetic heritability studies suggest environmental factors play a key role in pathogenesis. Detergents, such as sodium dodecyl sulfate (SDS), are common ingredients in household products such as dish soap and toothpaste. We hypothesized detergent exposure decreases epithelial barrier function and induces esophageal inflammation.MethodsImmortalized esophageal epithelial cells (EPC2) were cultured in air‐liquid interface (ALI) and exposed to SDS. Barrier function/activity was assessed by transepithelial electrical resistance (TEER), FITC‐dextran flux, and RT‐PCR. Additionally, SDS‐treated mouse esophageal organoids were evaluated for morphology. To investigate the effects of SDS in vivo, mice were treated with 0.5% SDS in drinking water for 14 days. Esophagi were assessed by gross morphology, histopathology, protein expression, and bulk RNA sequencing.ResultsWhen EPC2 cells were exposed to SDS (5 μg/ml) for 96 h, TEER decreased (p = 0.03), and FITC‐dextran flux increased (p = 0.0002). mRNA expression of IL‐33 increased 4.5‐fold (p = 0.02) at 6 h and DSG1 decreased (p < 0.0001) by 72 h. Disrupted epithelial integrity was noted in SDS‐treated esophageal organoids. When mice were exposed to SDS, they showed increased esophageal width, chemokine, and metalloprotease levels. Mice treated with SDS also showed increased IL‐33 protein expression, basal zone hyperplasia, CD4+ cell infiltration, and esophageal eosinophilia. RNA sequencing revealed upregulation of immune response pathway genes.ConclusionExposure to SDS decreases esophageal barrier integrity, stimulates IL‐33 production, and promotes epithelial hyperplasia and tissue eosinophilia. Detergents may be a key environmental trigger in EoE pathogenesis.

Abstract The impact of microbes on restraining the immune response to allergens has been extensively studied and is a key element of the hygiene hypothesis. Lung type 2 innate lymphoid cell responses to airway allergens can be inhibited by administration of a number of microbial products; however, it is unclear whether such an effect would be observed with natural infections and how sustained any observed inhibitory effects would be. To answer these questions, we used a murine model of physiological microbial exposures through cohousing SPF laboratory mice with pet store mice and examined the acute type 2 response to intranasally delivered fungal allergen extract Alternaria alternata. We found laboratory mice cohoused with pet store mice for two weeks display a suppressed ILC2 response to A. alternata which resulted in reduced eosinophilia. By comparison, mice cohoused for at least two months had ILC2 and eosinophil responses similar to SPF mice despite dramatic changes to the composition of the immune cell populations in the lungs. Lung ILC2 in two-month cohoused mice were still sensitive to subsequent inflammatory cues, as administration of poly(I:C) was able to suppress ILC2 activation and eosinophilia equally well in SPF and two-month cohoused animals. These findings suggest ILC2 dynamically respond to their environment and are not easily desensitized long-term.

Polyethyleneimine (PEI) induced immune responses were investigated in human bronchial epithelial (hBE) cells and mice. PEI rapidly induced ATP release from hBE cells and pretreatment with glutathione (GSH) blocked the response. PEI activated two conductive pathways, VDAC-1 and pannexin 1, which completely accounted for ATP efflux across the plasma membrane. Moreover, PEI increased intracellular Ca2+ concentration ([Ca2+]i), which was reduced by the pannexin 1 inhibitor, 10Panx (50 μM), the VDAC-1 inhibitor, DIDS (100 μM), and was nearly abolished by pretreatment with GSH (5 mM). The increase in [Ca2+]i involved Ca2+ uptake through two pathways, one blocked by oxidized ATP (oATP, 300 μM) and another that was blocked by the TRPV-1 antagonist A784168 (100 nM). PEI stimulation also increased IL-33 mRNA expression and protein secretion. In vivo experiments showed that acute (4.5 h) PEI exposure stimulated secretion of Th2 cytokines (IL-5 and IL-13) into bronchoalveolar lavage (BAL) fluid. Conjugation of PEI with ovalbumin also induced eosinophil recruitment and secretion of IL-5 and IL-13 into BAL fluid, which was inhibited in IL-33 receptor (ST2) deficient mice. In conclusion, PEI-induced oxidative stress stimulated type 2 immune responses by activating ATP-dependent Ca2+ uptake leading to IL-33 secretion, similar to allergens derived from Alternaria.

Background Recent investigations suggest that inflammation and autoimmunity might have a role in the pathophysiology of atrial fibrillation (AF). Given that abnormal ventriculovascular coupling often coexists with AF, we hypothesize that autoimmune vasculitis plays a significant role in the pathogenetic mechanism of AF. Methods and Results A standardized retrospective population‐based case–control study was conducted to evaluate the association between autoimmune vasculitis and AF, and all‐cause mortality. The study included 8459 patients with a new diagnosis of AF and 8459 age‐, sex‐, and registration calendar year–matched controls in Olmsted County, Minnesota, between January 1, 1980 and December 31, 2010. The association of each clinical characteristic, diagnosis, and treatment was assessed using conditional logistic regression to account for the matched case–control study design. Cox proportional hazards regression models and Kaplan‐Meier curves were used to detect independent predictors of mortality and examine cumulative survival. Of a total of 16 918 patients (mean age 72.3+14.4 years; 48.7% women), 320 (1.9%) were diagnosed with autoimmune vasculitis before the index date during the 30‐year period. Among the cases, the prevalence of any autoimmune vasculitis was 2.3%, whereas the frequency of autoimmune vasculitis in controls was 1.5% ( P <0.001). After adjusting for potential confounders, the odds of autoimmune vasculitis in AF cases was 1.5 times higher than in controls (odds ratio, 1.47; 95% CI, 1.04–2.01; P =0.03). Patients with AF and autoimmune vasculitis had worse 5‐year survival than those without autoimmune vasculitis or AF (44.7% versus 77.2%; log‐rank P <0.001). Conclusions Autoimmune vasculitis is significantly associated with AF and independently confers worse survival. These observations may represent one mechanism linking autoimmunity and inflammation to the pathogenesis and prognosis of AF.

Abstract The cyclooxygenase (COX) metabolic pathway regulates immune responses and inflammation. The effect of the COX pathway on innate pulmonary inflammation induced by protease-containing fungal allergens, such as Alternaria alternata, is not fully defined. In this study, we tested the hypothesis that COX inhibition augments Alternaria-induced pulmonary group 2 innate lymphoid cell (ILC2) responses and IL-33 release. Mice were treated with the COX inhibitors indomethacin, flurbiprofen, or vehicle and challenged intranasally with Alternaria extract for four consecutive days to induce innate lung inflammation. We found that indomethacin and flurbiprofen significantly increased the numbers of ILC2 and IL-5 and IL-13 expression by ILC2 in the lung. Indomethacin also increased ILC2 proliferation, the percentages of eosinophils, and mucus production in the lung. Both indomethacin and flurbiprofen augmented the release of IL-33 in bronchoalveolar lavage fluid after Alternaria challenge, suggesting that more IL-33 was available for ILC2 activation and that a COX product(s) inhibited IL-33 release. This is supported by the in vitro finding that the COX product PGE2 and the PGI2 analogs cicaprost decreased Alternaria extract–induced IL-33 release by human bronchial epithelial cells. Although contrasting effects of PGD2, PGE2, and PGI2 on ILC2 responses have been previously reported, the overall effect of the COX pathway on ILC2 function is inhibitory in Alternaria-induced innate airway inflammation.

Abstract Background Group 2 innate lymphoid cells (ILC2) are stimulated by IL‐33 to increase IL‐5 and IL‐13 production and airway inflammation. While sex hormones regulate airway inflammation, it remained unclear whether estrogen signaling through estrogen receptor‐α (ER‐α, Esr1 ) or ER‐β ( Esr2 ) increased ILC2‐mediated airway inflammation. We hypothesize that estrogen signaling increases allergen‐induced IL‐33 release, ILC2 cytokine production, and airway inflammation. Methods Female Esr1 ‐/‐ , Esr2 ‐/‐ , wild‐type (WT), and IL33 fl/fl eGFP mice were challenged with Alternaria extract (Alt Ext) or vehicle for 4 days. In select experiments, mice were administered tamoxifen or vehicle pellets for 21 days prior to challenge. Lung ILC2, IL‐5 and IL‐13 production, and BAL inflammatory cells were measured on day 5 of Alt Ext challenge model. Bone marrow from WT and Esr1 ‐/‐ female mice was transferred (1:1 ratio) into WT female recipients for 6 weeks followed by Alt Ext challenge. hBE33 cells and normal human bronchial epithelial cells (NHBE) were pretreated with 17β‐estradiol (E2), propyl‐pyrazole‐triol (PPT, ER‐α agonist), or diarylpropionitrile (DPN, ER‐β agonist) before allergen challenge to determine IL‐33 gene expression and release, extracellular ATP release, DUOX‐1 production, and necrosis. Results Alt Ext challenged Esr1 ‐/‐ , but not Esr2 ‐/‐ , mice had decreased IL‐5 and IL‐13 production, BAL eosinophils, and IL‐33 release compared to WT mice. Tamoxifen decreased IL‐5 and IL‐13 production and BAL eosinophils. IL‐33eGFP + epithelial cells were decreased in Alt Ext challenged Esr1 ‐/‐ mice compared to WT mice. 17β‐E2 or PPT, but not DPN, increased IL‐33 gene expression, release, and DUOX‐1 production in hBE33 or NHBE cells. Conclusion Estrogen receptor ‐α signaling increased IL‐33 release and ILC2‐mediated airway inflammation.

Abstract Peanut allergy is a growing public concern; however, little is known about the immunological mechanism(s) that initiate the disease process. Our knowledge is also limited regarding the role of group 2 innate lymphoid cells (ILC2s) in regulating humoral immunity. To fill these major gaps in our knowledge, we investigated the immunological mechanisms involved in peanut allergen sensitization by using mouse models. To mimic environmental exposure in humans, naive BALB/c mice were exposed to peanut flour by inhalation without any exogenous adjuvants. When exposed to peanut flour, naive mice developed T follicular helper (Tfh) cells in their lung draining lymph nodes and produced IgE Abs to peanuts. Mice deficient in IL-13 showed decreased numbers of Tfh cells and germinal center B cells and produced significantly fewer IgE Abs. IL-13 was necessary and sufficient for induction of CD11c+ MHC class IIhi dendritic cells that are implicated in Tfh cell development. Importantly, lung ILC2s served as a predominant early source of IL-13 when naive mice were exposed to peanut flour. Furthermore, mice that are deficient in lung ILC2s by bone marrow transfer from Rorasg/sg mice or by genetic manipulation produced significantly fewer IgE Abs to peanuts compared with control mice. These findings suggest lung ILC2s that serve as a rapid source of IL-13 upon allergen exposure play a major role in Tfh cell development, IgE Ab production, and initiation of peanut allergy.