Mite Antigen–Induced Perennial Allergic Conjunctivitis in Mice

Abstract

Abstract: : Purpose: To establish a mouse model for allergic conjunctivitis using a mite antigen, which is a common antigen for perennial allergic conjunctivitis in human. Methods: In active immunization model, C57BL/6J mice were sensitized with subcutaneous injection in two regions, left hind footpad and base of tail. Each injection composed of 50 µl containing 5 µg of soluble mite extract antigen (Df) emulsified with alum. Ten days later, mice were challenged with 50 µg of Df in eye drops. Twenty four hours after the challenge, they were sacrificed to harvest their eyes, blood, and spleen. Eyes were analysed histologically by counting eosinophils infiltrating into the conjunctiva. Total IgE in serum were measured. Splenocytes were cultured for proliferation analysis and cytokine assay. In passive immunization model, splenocytes harvested from actively immunized mice were stimulated in vitro with Df and then, 2x10⁷ in vitro stimulated cells were transferred intraperitoneally into C57BL/6J mice. Four days after the transfer, recipient mice were challenged and evaluated histologically as above. As a control, naive mice were challenged with Df and evaluated histologically. Results: Mice actively immunized with Df had higher infiltrating eosinophil numbers (average=17.1) in the conjunctiva than did passively immunized mice (average=7.5) or the control mice (average=3.7). Total IgE in serum was higher in actively immunized mice than the control mice. Df had a capacity to induce the proliferation of Df–sensitized splenocytes in a dose–dependent manner. Df–sensitized splenocytes produced both IFN–γ and IL–4 by stimulation of Df. Conclusions: Experimental PAC model induced by a soluble mite antigen was established in mice. From the finding that infiltrating eosinophils were more in actively immunized mice than passively immunized mice, it could be suggested that involvement of T cells during the effector phase is not remarkable in this PAC model.

Keywords: conjunctivitis • inflammation • pathology: experimental