Retinal S-antigen induced experimental autoimmune uvettis (EAU) is a severe, predominantly T-cell mediated inflammatory disease of the uveal tract and retina of the eye. Pretreatment of LEW rats with the monoclonal antibody, MAbS2.4.C5, which defines an epitope in S-antigen, has been shown to effectively inhibit the subsequent induction of EAU with S-antigen. Using synthetic peptides and cyanogen bromide fragments of S-anligen we found the binding site of MAbS2.4.C5 to be located at the carboxy terminus of the molecule corresponding to amino acid positions 375 to 380. Limited Staphylococcus aweus V8 protease digestion yielded several polypeptide fragments including one large 43 kD fragment which retained antibody binding to a variety of both polyclonal and monoclonal antibodies which identify epitopes that span the length of the S-antigen. This treatment, however, completely destroys the MAbS2.4.C5 binding site and dramatically reduces uveitopathogenicity. Limited trypsin and papain digestion, on the other hand, had little effect on pathogenicity or on MAbS2.4.C5 binding to S-antigen or its peptide fragments. These results indicate that the carboxy-terminus of S-antigen plays a predominant role in the pathogenesis of EAU.
Bibliographical noteFunding Information:
Supported in part by the Grampian Health Board, Aberdeen, Scotland, the Retina Service, Wills Eye Hospital, National Institutes of Health Grant EY5095 and BRSG5510, the Pennsylvania Lions Sight Conservation and Eye Research Foundation, the Crippled Children’s Vitreo-Retinal Research Foundation (David Meyer, Director), and Research to Prevent Blindness Inc. H. S. Dua is the Henry and Corinne Bower Retina Research Scholar; John V. Forrester is the Cockbum Professor of Ophthalmology, Aberdeen University; Larry A. Donoso, is the Thomas D. Duane Professor of Ophthalmology and the recipient of a Manpower Award from Research to Prevent Blindness Inc. Dale S. Gregerson is a Research to Prevent Blindness Senior Scientific Investigator.
- Monoclonal antibody