Sequence 168 to 177 of interphotoreceptor retinoid-binding protein (IRBP) is an antigenic epitope for autoreactive CD8 T cells in the B10RIII mouse

We previously demonstrated that a significant proportion of interphotoreceptor retinoid-binding protein (IRBP)-specific uveitogenic T cells in the C57BL/6 mouse and Lewis rat express CD8. The aims of this study were to determine whether some of the IRBP-specific T cells in the B10RIII mouse also express CD8 and whether CD8 and CD4 IRBP-specific T cells in the B10RIII mouse recognize a different or the same antigenic epitope. Our results show that autoreactive CD8 T cells were abundant in B10RIII mice immunized with the uveitogenic peptide IRBP161–180. Using multimers of recombinant H-2Dr molecules, we also showed that the binding of the H-2Dr fusion protein to IRBP161–180-expanded CD8 T cells was dependent on the peptide complexed with the recombinant molecules. The use of a panel of truncated peptides showed that the truncated 10-mer peptide, IRBP168–177, retained the ability to bind to, and stimulate, IRBP161–180-specific CD8 T cells after complexing with a dimeric MHC class I (H-2Dr) molecule. Finally, adoptive transfer of IRBP161–180-specific T cells stimulated with IRBP168–177 consistently induced mild, but significant, EAU in naïve B10RIII mice.