Invariant natural killer T-cell neutralization is a possible novel therapy for human eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a recently recognized inflammatory disorder that needs a potential therapeutic strategy. We earlier showed that iNKT cell-deficient mice are protected from allergen-induced EoE. Therefore, we now tested the hypothesis that iNKT cells are induced in the human EoE and is a novel possible target for the treatment of human EoE. Accordingly, we examine number of iNKT cells and eosinophils and expression of iNKT-associated cell surface receptors and chemokines by performing immunofluorescence, qPCR and ELISA in the esophageal biopsies and blood samples of normal subjects (comparison control) and EoE patients. Herein, we show that iNKT cell number, their receptor subcomponents Vα24 and Vβ11 expression, and associated chemokine CXCL16 levels (or expression) are induced significantly in EoE patients compared with normal individuals. In addition, we show that CXCL16 levels (or expression) correlate with the mRNA levels of Vα24 receptor but not well with esophageal eosinophilia in human EoE. Of note, we show that in vivo activation of iNKT cells is sufficient to induce EoE in mice. Furthermore, we show that anti-mCD1d- and anti-hVα24Jα18-neutralizing antibody treatment protects allergen-induced experimental EoE. Taken together, we have shown first time that iNKT cells have a critical pathogenic role in human and experimental EoE. iNKT cell neutralization by humanized anti-CD1d and anti-Vα24Jα18 antibodies might be a novel and potential therapy for human EoE.

Pathogenic role of mast cells in experimental eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic allergic disease characterized by esophageal intraepithelial eosinophils, extracellular eosinophil granule deposition, induced mast cell accumulation, and epithelial cell hyperplasia. However, the processes involved in the development of a number of these characteristics are largely unknown. Herein, we tested the hypothesis whether induced mast cell accumulation in the esophagus has a role in promoting EoE pathogenesis. Accordingly, we induced experimental EoE in wild-type mice, mast cell-deficient WWv mice, and mast cell-reconstituted WWv mice. We report that esophageal mast cell numbers increase in parallel with eosinophils in a dose- and time-dependent manner following the induction of allergen-induced EoE. The induced mast cells are localized in the esophageal lamina propria and muscular mucosa but have no influence on promoting esophageal eosinophilia. The 5'-bromodeoxyuridine (BrdU) incorporation analysis indicated that mast cells have a significant role in muscle cell hyperplasia and hypertrophy. In addition, the wild-type and mast cell-reconstituted WWv mice showed a comparable number of BrdU⁺ cells in the esophageal muscular mucosa following allergen-induced EoE. In conclusion, we provide for the first time direct evidence that mast cell promotes muscle cell hyperplasia and hypertrophy and may have a significant role in promoting esophageal functional abnormalities in EoE.