Characterization of Clinical and Immune Responses in an Experimental Chronic Autoimmune Uveitis Model

Autoimmune uveitis is a sight-threatening intraocular inflammatory disease. For >30 years, the mouse model of experimental autoimmune uveitis has been employed to investigate disease mechanisms and test immunotherapeutic approaches. However, inflammation in this model is self-limited, and does not replicate the chronic, insidious nature prevalent in the human disease. Herein, a robust and reliable model of chronic autoimmune uveitis was developed and characterized in two strains of wild-type mice by modifying interphotoreceptor retinoid-binding protein dose and peptide fragments from conventional experimental autoimmune uveitis models. In both of these murine strains, immunization with our modified protocols resulted in a slowly progressive uveitis, with retinal scars and atrophy observed in the chronic stage by fundoscopy. Optical coherence tomography demonstrated decreased retinal thickness in chronic autoimmune uveitis mice, and electroretinography showed significantly reduced amplitudes of dark-adapted a- and b-waves and light-adapted b-waves. Histologic examination revealed prominent choroiditis with extensive retinal damage. Flow cytometry analysis showed substantially increased numbers of CD44^hiIL-17⁺IFN-γ^- memory T-helper 17 (Th17) cells in the retina, cervical lymph nodes, inguinal lymph nodes, and spleen. These data establish new modified protocols for inducing chronic uveitis in wild-type mice, and demonstrate a predominant memory Th17 cell response, suggesting an important role for memory Th17 cells in driving chronic inflammation in autoimmune uveitis.