Experimental autoimmune uveo-retinitis and specificity of retinal antigens

Chorio-retinal lesions induced in guinea pigs after one inoculation of bovine rod outer segments (ROS) with complete Freund's adjuvant are described with light and electron microscopy. The auto-antigenic activity of different preparations from bovine retina and uvea is compared for their efficacy to induce the disease. ROS are much more active than total retina homogenate. Pigment epithelium is active, and the effect of choroid is impaired after removal of pigment epithelium from the surface of the choroid. Purification of ROS by several sucrose flotations does not reduce their activity. Almost complete extraction of soluble antigens from pure ROS by buffer washings, controlled with isoelectrofocusing and immunodiffusion, decreases only slightly their pathogenicity. Rhodopsin, extracted using cetyltrimethylammonium bromide from pure washed ROS, induced prominent chorio-retinal damage at the dose of 500 mug. It seems likely that besides soluble retinal auto-antigens, outer segments contain a pathogenic insoluble antigen which seems to be linked to rhodopsin or to be rhodopsin itself.