Abstract
PURPOSE: To explore the role of Th2 signaling pathway in allergic conjunctivitis (AC). METHODS: Serum Th2 cytokines IL-4 or IL-13 of patients with AC were detected using the Meso scale discovery assay to verify the correlation of Th2 immunity and AC pathogenesis. Wistar Han rats were intraperitoneally and subcutaneously injected with ovalbumin (OVA) to establish an experimental AC model and the Th2 signaling pathway was blocked by an investigational neutralizing antibody (CM310). Serum IgE and OVA-specific IgE were detected by ELISA. Conjunctivitis inflammation, infiltration of eosinophils, and mast cell degranulation were detected by histological examination. Immortalized human conjunctival epithelial cells, a conjunctival epithelial cell line, and peripheral blood mononuclear cells of patients with AC were used as the target cells to study the impact of IL-4 or IL-13 on AC progression. Finally, a STAT6 reporter gene system was constructed using immortalized human conjunctival epithelial cells to confirm whether the downstream signaling pathway activated by IL-4 or IL-13. RESULTS: Serum IL-4 or IL-13 were increased in patients with AC versus healthy individuals. In an OVA-induced rat experimental AC model, blocking the Th2 signaling pathway with CM310, an investigational neutralizing antibody, alleviated the conjunctival symptoms, and decreased serum IgE, suppressed infiltration of eosinophils and mast cell degranulation. Further, an in vitro model showed CM310 suppressed the secretion of inflammatory cytokine from both immune cells and epithelial cells in both patients peripheral blood mononuclear cells and cell line. CONCLUSIONS: Blocking Th2 signaling pathway alleviates the clinical symptoms and inflammation in AC.