Purification of bovine interphotoreceptor retinoid-binding protein and its uveitogenicity in Lewis rats.

Interphotoreceptor retinoid-binding protein, IRBP, not only functioning as a shuttle to carry the retinoid between photoreceptor cells and pigment epithelium, but also inducing experimental autoimmune uveoretinitis (EAU), was purified by ConA Sepharose affinity chromatography from the fractions containing IRBP obtained in the course of ion-exchange chromatography by which the bovine retinal S-antigen was purified. This much simplified method allows more rapid purification of the two kinds of protein. EAU was successfully induced with injecting 50 micrograms of IRBP emulsified with Freund's complete adjuvant into the right hind footpads of Lewis rats. It was characterized by panophthalmia or endophthalmia with the severest damage in the posterior retina. Lymphocytes, mononuclear and polymorphonuclear cells were found to be the inflammatory cells of infiltration, with lymphocytes being predominant.