Topical Application of Interleukin-28A Attenuates Allergic Conjunctivitis in an Ovalbumin-Induced Mouse Model

PURPOSE. Allergic conjunctivitis (AC) is an immunoglobulin E (IgE)-mediated and helper T cell 2 (Th2)-cell-mediated disease characterized by conjunctival eosinophilic infiltration. Previous study shows that IL-28A had anti-allergic activity in airway disease. In this study, we examined the effect of IL-28A on a mouse model of ovalbumin (OVA)-induced experimental allergic conjunctivitis (EAC). METHODS. Mouse EAC was induced by topical application of OVA after intraperitoneal (IP) sensitization with OVA in aluminum hydroxide (ALUM). Interleukin-28A was administered 1 hour before OVA challenge. Allergic conjunctivitis symptoms, eosinophil infiltration in the conjunctiva, antigen-specific IgE in the serum, and Th2 cytokine production by lymph node cells and splenocytes were subsequently analyzed. RESULTS. Topical application of IL-28A to OVA-induced EAC reduced clinical symptoms, serum OVA-specific IgE, and the infiltration of eosinophils in the conjunctiva. In addition, topical administration of IL-28A suppressed the expression of IL-4, IL-5, and IL-13 (Th2-type cytokine) but promoted the expression of IFN-c (Th1-type cytokine) by splenocytes and cervical lymph node cells in EAC mice. Immunofluorescence staining showed decrease expression of IL-4 and IL-5 in IL-28A-treated EAC conjunctiva. CONCLUSIONS. Interleukin-28A shows therapeutic potential for allergic conjunctival inflammation.