Epithelial overexpression of IL-33 induces eosinophilic esophagitis dependent on IL-13.

BACKGROUND: Eosinophilic esophagitis (EoE) is an increasingly common inflammatory condition of the esophagus; however, the underlying immunologic mechanisms remain poorly understood. The epithelium-derived cytokine IL-33 is associated with type 2 immune responses and elevated in esophageal biopsy specimens from patients with EoE. OBJECTIVE: We hypothesized that overexpression of IL-33 by the esophageal epithelium would promote the immunopathology of EoE. METHODS: We evaluated the functional consequences of esophageal epithelial overexpression of a secreted and active form of IL-33 in a novel transgenic mouse, EoE33. EoE33 mice were analyzed for clinical and immunologic phenotypes. Esophageal contractility was assessed. Epithelial cytokine responses were analyzed in three-dimensional organoids. EoE33 phenotypes were further characterized in ST2-/-, eosinophil-deficient, and IL-13-/- mice. Finally, EoE33 mice were treated with dexamethasone. RESULTS: EoE33 mice displayed ST2-dependent, EoE-like pathology and failed to thrive. Esophageal tissue remodeling and inflammation included basal zone hyperplasia, eosinophilia, mast cells, and TH2 cells. Marked increases in levels of type 2 cytokines, including IL-13, and molecules associated with immune responses and tissue remodeling were observed. Esophageal organoids suggested reactive epithelial changes. Genetic deletion of IL-13 in EoE33 mice abrogated pathologic changes in vivo. EoE33 mice were responsive to steroids. CONCLUSIONS: IL-33 overexpression by the esophageal epithelium generated immunopathology and clinical phenotypes resembling human EoE. IL-33 may play a pivotal role in the etiology of EoE by activating the IL-13 pathway. EoE33 mice are a robust experimental platform for mechanistic investigation and translational discovery.

Machine learning-based identification and characterization of mast cells in eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is diagnosed and monitored using esophageal eosinophil levels; however, EoE also exhibits a marked, understudied esophageal mastocytosis. OBJECTIVES: Using machine learning, we localized and characterized esophageal mast cells (MCs) to decipher their potential role in disease pathology. METHODS: Esophageal biopsy samples (EoE, control) were stained for MCs by anti-tryptase and imaged using immunofluorescence; high-resolution whole tissue images were digitally assembled. Machine learning software was trained to identify, enumerate, and characterize MCs, designated Mast Cell-Artificial Intelligence (MC-AI). RESULTS: MC-AI enumerated cell counts with high accuracy. During active EoE, epithelial MCs increased and lamina propria (LP) MCs decreased. In controls and EoE remission patients, papillae had the highest MC density and negatively correlated with epithelial MC density. MC density in the epithelium and papillae correlated with the degree of epithelial eosinophilic inflammation, basal zone hyperplasia, and LP fibrosis. MC-AI detected greater MC degranulation in the epithelium, papillae, and LP in patients with EoE compared with control individuals. MCs were localized further from the basement membrane in active EoE than EoE remission and control individuals but were closer than eosinophils to the basement membrane in active EoE. CONCLUSIONS: Using MC-AI, we identified a distinct population of homeostatic esophageal papillae MCs; during active EoE, this population decreases, undergoes degranulation, negatively correlates with epithelial MC levels, and significantly correlates with distinct histologic features. Overall, MC-AI provides a means to understand the potential involvement of MCs in EoE and other disorders.

Abnormalities in esophageal smooth muscle induced by mutations in collagen XIX.

Collagen XIX is a nonfibrillar collagen that localizes in restricted tissues at very low amounts. A previous study on Col19a1 null mice revealed that collagen XIX is involved in esophageal muscle physiology and morphogenesis. Here, we use histological analysis to show that mice with a Col19a1 mutant lacking the NC3 domain and seven collagen triplets display abnormal transition of smooth to striated muscle in the abdominal segment of esophagus, and a widened esophagus with age. With two newly prepared antibodies, we analyzed the expression of collagen XIX in the mouse esophagus and show that collagen XIX colocalizes with α-smooth muscle actin. By immunoelectron microscopy, we confirmed the localization of collagen XIX in esophageal smooth muscle cells. Col19a1 mutant mice contained reduced levels of mutated Col19a1 mRNA. Interestingly, hepatocyte growth factor, which has an important role in esophageal striated muscle development, was reduced in the esophagus of the Col19a1 mutant mice. These findings suggest that collagen XIX may be critical for the function of esophageal smooth muscle cells as a scaffold for anteroposterior migration of esophagus-striated muscle cells.

Salivary Trefoil Factor Family (TFF) Peptides and Their Roles in Oral and Esophageal Protection: Therapeutic Potential.

Human saliva is a complex body fluid with more than 3000 different identified proteins. Besides rheological and lubricating properties, saliva supports wound healing and acts as an antimicrobial barrier. TFF peptides are secreted from the mucous acini of the major and minor salivary glands and are typical constituents of normal saliva; TFF3 being the predominant peptide compared with TFF1 and TFF2. Only TFF3 is easily detectable by Western blotting. It occurs in two forms, a disulfide-linked homodimer (Mr: 13k) and a high-molecular-mass heterodimer with IgG Fc binding protein (FCGBP). TFF peptides are secretory lectins known for their protective effects in mucous epithelia; the TFF3 dimer probably has wound-healing properties due to its weak motogenic effect. There are multiple indications that FCGBP and TFF3-FCGBP play a key role in the innate immune defense of mucous epithelia. In addition, homodimeric TFF3 interacts in vitro with the salivary agglutinin DMBT1gp340. Here, the protective roles of TFF peptides, FCGBP, and DMBT1gp340 in saliva are discussed. TFF peptides are also used to reduce radiotherapy- or chemotherapy-induced oral mucositis. Thus, TFF peptides, FCGBP, and DMBT1gp340 are promising candidates for better formulations of artificial saliva, particularly improving wound healing and antimicrobial effects even in the esophagus.

Correlation of clinical symptoms, endoscopic features and density of oesophageal eosinophilia in children with newly-diagnosed eosinophilic esophagitis.

INTRODUCTION AND OBJECTIVE: Eosinophilic esophagitis (EoE) is an inflammatory immune-mediated oesophageal disease of growing prevalence. The aim of this study is to characterise the clinical symptoms, endoscopic features and histological findings, as well as their possible correlations, in newly-diagnosed EoE paediatric patients. MATERIAL AND METHODS: Between 2009-2018, the clinical records of patients diagnosed with EoE at the Paediatric Hospital in Warsaw, Poland, were retrospectively reviewed. Inclusion criteria were upper gastrointestinal tract symptoms in association with oesophageal mucosal biopsy specimens containing not less than 15 intraepithelial eosinophils per hpf. The prevalence and the possible correlations between symptoms, endoscopic features and the density of eosinophilic infiltration were analysed; the medical history of the comorbidities were also assessed. RESULTS: The study included 47 children (median age 9.5 years). The most common clinical symptoms were abdominal pain (53%) and GERD-like symptoms (26%). The most common macroscopic changes were white plaques and exudates in 47% and furrows in 34%. A macroscopically normal oesophagus was observed in 28% of the children. The median number of eosinophils was estimated to be 45 eosinophils/hpf (IQR: 30-60), and no significant differences were found between the density of eosinophil infiltration and clinical symptoms or endoscopic features. Moreover, 70% of the children had a history of an allergy disease, older children (>3 years) tended to have pollen allergy more often than younger children (p<0.05). CONCLUSIONS: The density of oesophageal eosinophilia does not correlate with symptoms or endoscopic findings in children with newl-diagnosed EoE.

Race-specific characteristics in pediatric eosinophilic esophagitis in an urban inner-city clinic.

BACKGROUND: Manifestations of pediatric eosinophilic esophagitis (EoE) are varied and dictated by multiple factors. The influence of race is limited to small observational cohorts of dichotomized data (Whites vs non-Whites) or single-racial analysis. OBJECTIVE: To better understand phenotypic variability in the manifestation and atopic sensitization of pediatric EoE, from the perspective of race. METHODS: Retrospective observational cohort study performed at a tertiary referral center. Subjects were included if less than 21 years old, with suggestive clinical features and histopathologic (>15 eosinophils/high-power field [hpf]) confirmation of EoE. Statistical computation was performed using Stata/IC 11 on variables of interest. RESULTS: A total of 34 subjects were included in the analysis. The median (interquartile range [IQR]) age for initial atopy was 2 (1-5) years. The median (IQR) age for EoE diagnosis was 5 (3-8) years. Age of EoE diagnosis was higher for Black or African Americans than non-Black or African Americans (P = .01). Between the racial groups, there was no difference in the total number of food sensitizations (P = .13), yet environmental allergy testing revealed that Black or African Americans were more likely to be sensitized for weeds (P = .03), dog (P = .009), and mold (P = .006). On histopathologic analysis, Black or African American subjects were found to have more prominent midesophageal eosinophilia at median 50/hpf (20-80/hpf), whereas Hispanic or LatinXs have more prominent lower esophageal eosinophilia at median 40/hpf (IQR, 20-40/hpf), compared with the other races (P = .04 and P = .04, respectively). CONCLUSION: Black or African Americans are more likely to present at an older age, have aeroallergen sensitization, and have more prominent midesophageal eosinophilia.

A unique esophageal extracellular matrix proteome alters normal fibroblast function in severe eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is a chronic TH2 disorder complicated by tissue fibrosis and loss of esophageal luminal patency. The fibrostenotic esophagus does not respond well to therapy, but profibrotic therapeutic targets are largely unclear. OBJECTIVE: Our aim was to utilize proteomics and primary cells as a novel approach to determine relevant profibrotic factors. METHODS: We utilized primary esophageal EoE and normal fibroblasts, their derivative extracellular matrixes (ECMs), an approach of fibroblast culture on autologous versus nonautologous ECM, and proteomics to elucidate EoE ECM proteins that dysregulate cellular function. RESULTS: We cultured esophageal fibroblasts from normal esophagi and esophagi from patients with severe EoE on autologous versus nonautologous ECM. The EoE ECM proteome shifted normal esophageal fibroblast protein expression. Proteomic analysis demonstrated that thrombospondin-1 is detected only in the EoE ECM, is central in the EoE ECM protein-protein interactome, is found at significantly elevated levels in biopsy specimens from patients with active EoE, and induces fibroblast collagen I production. CONCLUSION: Fibroblasts from patients with EoE secrete a unique ECM proteome that reflects their in vivo state and induces collagen I and α-smooth muscle actin protein expression from normal fibroblasts. Thrombospondin-1 is a previously unappreciated profibrotic molecule in EoE.

Conserved IFN Signature between Adult and Pediatric Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is an allergic inflammatory disease of the esophagus that occurs in both children and adults. Previous studies of affected tissue from pediatric cohorts have identified prominent signatures of eosinophilia and type 2 inflammation. However, the details of the immune response in adults with EoE are still being elucidated. To determine whether EoE in adults shares inflammatory profiles with those observed in children, we performed RNA sequencing of paired human esophageal biopsies and blood samples from adults with EoE or gastroesophageal reflux disease. Unbiased analysis of differentially expressed genes in tissue revealed a strong IFN signature that was significantly enriched in EoE patients as compared with patients with gastroesophageal reflux disease. Both type I and type II IFN-responsive genes were upregulated in adult biopsies, but not in blood. A similar increase in expression of IFN gene sets was observed in pediatric EoE biopsies as compared with non-EoE samples, and in public pediatric and adult RNA-sequencing data. Finally, we found that human peripheral CD4+ T cells from children with EoE produce IFN-γ upon activation with EoE-causal allergens. Together, this work identifies a conserved IFN signature in pediatric and adult EoE, highlighting a role for non-type 2 inflammatory networks in the disease process in humans.

Elimination of NF-κB signaling in Vimentin+ stromal cells attenuates tumorigenesis in a mouse model of Barrett's Esophagus.

Chronic inflammation induces Barrett's Esophagus (BE) which can advance to esophageal adenocarcinoma. Elevated levels of interleukin (IL)-1b, IL-6 and IL-8 together with activated nuclear factor-kappaB (NF-κB), have been identified as important mediators of tumorigenesis. The inflammatory milieu apart from cancer cells and infiltrating immune cells contains myofibroblasts (MFs) that express aSMA and Vimentin. As we observed that increased NF-κB activation and inflammation correlates with increased MF recruitment and an accelerated phenotype we here analyze the role of NF-κB in MF during esophageal carcinogenesis in our L2-IL-1B mouse model. To analyze the effect of NF-κB signaling in MFs, we crossed L2-IL-1B mice to tamoxifen inducible Vim-Cre (Vim-CreTm) mice and floxed RelA (p65fl/fl) mice to specifically eliminate NF-κB signaling in MF (IL-1b.Vim-CreTm.p65fl/fl). The interaction of epithelial cells and stromal cells was further analyzed in mouse BE organoids and patient-derived human organoids. Histological scoring of IL-1b.Vim-CreTm.p65fl/fl mice showed a significantly attenuated phenotype compared with L2-IL-1B mice, with mild inflammation, decreased metaplasia and no dysplasia. This correlated with decreased proliferation and increased differentiation in cardia tissue of IL-1b.Vim-CreTm.p65fl/fl compared with L2-IL-1B mice. Distinct changes of cytokines and chemokines within the local microenvironment in IL-1b.Vim-CreTm.p65fl/fl mice reflected the histopathological abrogated phenotype. Co-cultured NF-κB inhibitor treated MF with mouse BE organoids demonstrated NF-κB-dependent growth and migration. MFs are essential to form an inflammatory and procarcinogenic microenvironment and NF-κB signaling in stromal cells emerges as an important driver of esophageal carcinogenesis. Our data suggest anti-inflammatory approaches as preventive strategies during surveillance of BE patients.

A study of the immune infiltrate and patient outcomes in esophageal cancer.

OBJECTIVES: Cancer patient outcomes and selection for novel therapies are heavily influenced by the immune contexture of the tumor microenvironment. Esophageal cancer is associated with poor outcomes. In contrast to colorectal cancer, where the immunoscore is increasingly used in prognostic staging, little is known about the immune cell populations in esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (SCC), and their clinical significance. METHODS: Tissue microarrays were constructed from resected tumor tissue of 72 EAC patients and 23 SCC patients. Immunohistochemical staining of CD3, CD8, CD56, CD68, CD45RO, CD69, IFN-γ, IL-10, IL-4, IL-17, TGF-ß, FOXP3 and CD107a was performed. Positivity was examined in both the stromal and epithelial compartments. Statistical analysis was performed to identify differences in immune cell infiltration and functional phenotypes between cancer subtypes and tissue compartments. RESULTS: This study identified that esophageal tumors are enriched with CD45RO+ and CD8+ cells and such positivity is significantly higher in SCC compared with EAC. Furthermore, the expression of CD45RO positively correlates with that of CD8 within the tumors of both patient cohorts, suggesting a dominance of memory cytotoxic T cells. This is supported by strong positivity of degranulation marker CD107a in the stromal compartment of EAC and SCC tumors. Cytokine staining revealed a mixed pro- and anti-inflammatory profile within EAC tumors. CONCLUSIONS: Esophageal tumors are enriched with memory cytotoxic T cells. Applying these measurements to a larger cohort will ascertain the clinical utility of assessing specific lymphocyte infiltrates in EAC and SCC tumors with regards to future immunotherapy use, patient prognosis and outcomes.

Low Expression of ICAM-1 in Blood Eosinophils in Patients With Active Eosinophilic Esophagitis.

BACKGROUND AND OBJECTIVE: Eosinophilic esophagitis (EoE) is a chronic and isolated inflammation of the esophagus characterized by a marked infiltration of eosinophilic leukocytes. Diagnosis and course of the disease are based exclusively on histopathology. Therefore, patients must undergo several esophageal biopsies, implying a risk associated with the procedure and considerable use of resources. Objective: The presence of active circulating eosinophils, which are quantifiable through the expression of specific cellular activation proteins in their membrane, could be consistent with histopathological findings, which are currently the only valid parameters in studies on EoE. METHODS: The activity of peripheral blood eosinophils from patients with EoE was analyzed by identifying 5 surface molecules (CD69, IL- 5Rα, CD44, ICAM-1, CD63), which are seen to be expressed by the active eosinophils in flow cytometry. The results were compared with the infiltrate of eosinophils present in patients' esophageal biopsies. RESULTS: ICAM-1 levels decreased significantly in patients with active EoE compared with nonactive EoE patients, allergic patients, and healthy controls. In patients with EoE, an inverse correlation was observed between the number of eosinophils in the esophageal biopsy and the percentage of ICAM-1 expression in peripheral blood eosinophils. No differences were observed for the remaining molecules studied. CONCLUSION: Expression of ICAM-1 in blood eosinophils could be a useful noninvasive marker for the diagnosis and assessment of patients with EoE.

A study of multinucleated giant cells in esophageal cancer.

OBJECTIVES: To evaluate the occurrence, abundance, distribution, nature and clinical significance of multinucleated giant cell (MGC) in esophageal cancer. MATERIALS AND METHODS: MGCs were examined with conventional pathology, immunohistochemistry and immunofluorescence in 107 esophageal cancer tissues. The findings were correlated to pathological diagnosis and clinical behavior of the cancers. RESULTS: MGCs were identified in 31.7% (34/107) of the cases. MGCs were positive for CD11c, CD11b, CD32, CD16, HLA-DR and MMP9, and negative for CD163, CD206 and CD64 giving a molecular profile of proinflammatory M1 but not immunosuppressive M2. MGCs were significantly related to decreased lymph node metastasis (p = 0.011), low pTNM stage (p = 0.044), favorable survival (p = 0.04), squamous cell cancer type rather than other histopathological subtypes (p = 0.020) and associated to better differentiation (p = 0.063). CONCLUSIONS: MGCs belong to M1 macrophage and perform phagocytosis and scavenging of cancer cells that would benefit patients' survival and could serve as a prognostic marker.

Eosinophils in Eosinophilic Esophagitis: The Road to Fibrostenosis is Paved With Good Intentions.

Eosinophilic esophagitis (EoE) is an antigen-driven disease associated with epithelial barrier dysfunction and chronic type 2 inflammation. Eosinophils are the defining feature of EoE histopathology but relatively little is known about their role in disease onset and progression. Classically defined as destructive, end-stage effector cells, eosinophils (a resident leukocyte in most of the GI tract) are increasingly understood to play roles in local immunity, tissue homeostasis, remodeling, and repair. Indeed, asymptomatic esophageal eosinophilia is observed in IgE-mediated food allergy. Interestingly, EoE is a potential complication of oral immunotherapy (OIT) for food allergy. However, we recently found that patients with peanut allergy may have asymptomatic esophageal eosinophilia at baseline and that peanut OIT induces transient esophageal eosinophilia in most subjects. This is seemingly at odds with multiple studies which have shown that EoE disease severity correlates with tissue eosinophilia. Herein, we review the potential role of eosinophils in EoE at different stages of disease pathogenesis. Based on current literature we suggest the following: (1) eosinophils are recruited to the esophagus as a homeostatic response to epithelial barrier disruption; (2) eosinophils mediate barrier-protective activities including local antibody production, mucus production and epithelial turnover; and (3) when type 2 inflammation persists, eosinophils promote fibrosis.

Diagnosis of oesophageal mucormycosis managed with medical therapy alone.

Mucormycosis is an invasive mould that can cause aggressive infection, particularly in immunocompromised patients. Though oesophageal mucormycosis is relatively rare, it remains an elusive and devastating manifestation of this disease. The management is also challenging, due to surgical morbidity and contraindications such as thrombocytopenia in immunocompromised hosts. In this report, we present the case of a 60-year-old Lebanese man with newly diagnosed acute myeloid leukaemia who developed oesophageal mucormycosis after induction chemotherapy with idarubicin/cytarabine (7+3). The diagnosis was made when the patient developed febrile neutropenia and odynophagia. CT scan of the chest revealed a thickened oesophagus. Oesophagogastroduodenoscopy with biopsy, histopathology and PCR were performed, resulting in the diagnosis of Rhizopus microsporus The patient was successfully treated with liposomal amphotericin B and salvage posaconazole therapy without surgical intervention. We reviewed the clinical characteristics of the six published oesophageal mucormycosis reports from the literature.

Gastric Juice Expression of Th-17 and T-Reg Related Cytokines in Scleroderma Esophageal Involvement.

BACKGROUND: Systemic sclerosis (SSc) is a connective tissue disorder which key feature is a fibrotic process. The role of Endothelin-1 (ET-1) and T-helper (Th)-1 cells in lung and skin fibrosis is well known, although Th17- and Treg-cells were found to be involved. However, no studies analyzed cytokines expression in gastric-juice of SSc patients. Our study aimed to evaluate proinflammatory and profibrotic cytokines in gastric-juice of SSc patients and to investigate their correlations with esophageal dysmotility. METHODS: Patients performed upper-gastrointestinal-endoscopy with gastric-juice collection, esophageal manometry and thoracic CT-scan. GM-CSF, ET-1, Th-1 (IFN-γ, IL-1ß, TNF-α, IL-2, IL-6, IL-9), Th-17 (IL-17, IL-21, IL-22, IL-23) and T-reg (IL-10, TGF-ß) related cytokines were measured in 29 SSc-patients and 20 healthy-controls. RESULTS: Patients showed significant lower levels of IL-6, IL-17, IL-22 and ET-1 (p < 0.005) compared with controls. Patients with atrophic gastritis presented significant lower levels of IL-2, IL-9, IL-6, TGF-ß, GM-CSF, IL-17 and ET-1 (p < 0.005) compared to patients without gastritis. Increased values of IL-2, IL-9, IL-1ß, IL-17, ET-1 and GM-CSF (p < 0.005) were observed in patients with esophageal impairment. This is the first report of cytokines measurement in gastric juice of patients with SSc. The high IL-17 concentrations in gastric-juice of scleroderma patients with esophageal dysmotility support the signature of Th-17 cells in scleroderma esophageal fibrosis.

Inflammatory conditions of the esophagus: an update.

A variety of inflammatory disorders involve the esophagus. This commentary discusses the pathology of some forms of esophagitis, with an emphasis on recent developments. The initial section focuses on some common forms of nonreflux esophagitis, including lymphocytic esophagitis and eosinophilic esophagitis. Recent studies suggest that lymphocytic esophagitis may be associated with esophageal motility disorders and gastroesophageal reflux disease. Immunophenotypic features of intraepithelial lymphocytes may be helpful in distinguishing these conditions. Updates on the criteria and the limitations of histologic approach to the diagnosis of eosinophilic esophagitis are presented and new diagnostic adjuncts are discussed. In the remaining section, novel entities, such as IgG4-related esophagitis, are discussed. IgG4-related esophagitis has been recognized as a cause of esophageal lymphoplasmacytic inflammation. Increased understanding of esophageal inflammation remains an important goal that likely will lead to new approaches in the therapy of inflammatory esophageal diseases.