Expression of stress-response protein 60 in iritis associated with experimental autoimmune encephalomyelitis.

PURPOSE To study the expression of stress-response proteins in the inflamed iris of rats with experimental autoimmune encephalomyelitis (EAE). METHODS EAE was induced in Lewis rats by immunization with homogenized spinal cord of the guinea pig emulsified in complete Freund's adjuvant (CFA) (group EAE). Control rats included those immunized with only CFA (group CFA) and those that were untreated (group Normal). Immunohistochemical study for the localization of stress-response protein (srp) 27, srp 60, srp 72, ubiquitin, and alphaB-crystallin was performed. RESULTS All rats in group EAE developed iritis, whereas none of the rats in group CFA and group Normal developed iritis. No expression of ubiquitin, alphaB-crystallin, srp 27, srp 60, or srp 72 was seen in the epithelium of the iris in group CFA rats. In the eyes of rats in group EAE, srp 60 was expressed in the epithelium of the iris in 20 of 22 (90.9%), ubiquitin in 4 of 22 (18.2%), and alphaB-crystallin in 3 of 22 (13.6%). In the group Normal rats, only ubiquitin was expressed in the epithelium of the iris in 1 of 6 (16.7%) eyes examined. CONCLUSIONS These results suggest that srp 60 may be a potential uveitogenic antigen in the iris in EAE.