Experimental autoimmune uveoretinitis was induced in rats after one injection of purified retinal S antigen mixed with adjuvants. Lewis and PVG/c rat strains were highly sensitive. S antigens isolated from bovine, human, swine and guinea pig retinas had a high pathogenicity in Lewis rats, whereas allogenic S antigen did not induce the disease. Mycobacterial adjuvant was effect in both disease and antibody production but H. pertussis adjuvant strongly increased the severity of the ocular reaction, giving a hyperacute Arthus-type inflammation, even with low doses of antigen. No disease was found after immunization without bacteria (incomplete Freund's adjuvant or alum). With any bacterial adjuvant, the histological pattern was in agreement with the hypothesis of early reagin-mediated phenomena acting on the blood-retinal barrier, as suggested by previous experiments.

A single injection of 100 μg of lipopolysaccharide from Salmonella typhimurium in the foot pads of Lewis rats induced acute inflammation of the eye. Clinically, the disease started as early as 0.5 h and peaked 18 h after the inoculation. The aqueous protein concentration was increased after the inoculation. Histopathologically, cellular infiltrates and proteinaceous exudates were observed in the anterior segment (anterior chamber, iris and ciliary body). In addition to those changes described in previous reports, the examination of the posterior segment showed retinal vasculitis, hemorrhagic exudates, focal destruction of photoreceptor cells and choroidal infiltration.

Hybridomas producing monoclonal antibodies to the retinal S antigen were obtained by fusion of spleen cells from a BALB/c mouse immunized with purified bovine S antigen and NS-1 myeloma cells. Six cloned hybridomas were selected and expanded as large scale cultures and as ascites in mice. The specificity of the antibodies produced by these hybridomas was assessed by ELISA and immunofluorescence. All were specific for S antigen, except one which showed slight reactivity with other proteins. One antibody was specific for bovine S antigen, whereas the others showed cross reactivity with purified S antigens from various mammals. Immunofluorescence allowed to demonstrate the presence of common epitopes of S antigen in the retinal photoreceptor cells of species representative of every class of Vertebrates.