The uveitogenic potential of retinal S–antigen in horses

Abstract

Abstract: : Purpose: To investigate the uveitogenic potential of retinal S–antigen (S–Ag) in horses. Methods: Horses were immunized subcutaneously with S–Ag or BSA as control antigen, emulsified in complete Freund's adjuvant. Simultaneously, B. pertussis was given intravenously. Antigen specific T and B cell responses were analysed in a 3 day interval. Disease development was judged clinically and histopathologically. Two identical booster immunizations were given every four weeks in order to test induction of recurrences. Results: T and B cell responses specific for S–Ag were observed in all immunized horses but were absent in control animals. However, only one of 5 animals developed uveitis. Reimmunization with S–Ag did not lead to a uveitic relapse in this horse. All other horses of the S–Ag and BSA–treated group did neither develop any signs of uveitis, nor had inflammatory infiltrates of the inner eye. Conclusions: Here we show that, in contrast to IRBP, S–Ag is a weak autoantigen in horses. Even though S–Ag immunization leads to the activation of autoreactive T and B–cells, infiltration of the inner eye and induction of uveitis is controlled in the majority of horses.

Keywords: uveitis–clinical/animal model • autoimmune disease