Infection by Leptospira interrogans has been causally associated with human and equine
uveitis. Studies in our laboratories have demonstrated that leptospiral
lipoprotein LruA and LruB are expressed in the eyes of uveitic horses, and that
antibodies directed against LruA and LruB react with equine lenticular and
retinal extracts, respectively. These reactivities were investigated further by performing immunofluorescent assays on lenticular and
retinal tissue sections. Incubation of lens tissue sections with LruA-antiserum and
retinal sections with LruB-antiserum resulted in positive fluorescence. By employing two-dimensional gel analyses followed by immunoblotting and mass spectrometry,
lens proteins cross-reacting with LruA antiserum were identified to be
alpha-crystallin B and
vimentin. Similarly, mass spectrometric analyses identified
beta-crystallin B2 as the
retinal protein cross-reacting with LruB-antiserum. Purified recombinant human
alpha-crystallin B and
vimentin were recognized by LruA-directed antiserum, but not by control pre-immune serum. Recombinant
beta-crystallin B2 was likewise recognized by LruB-directed antiserum, but not by pre-immune serum. Moreover, uveitic eye fluids contained significantly higher levels of antiibodies that recognized
alpha-crystallin B,
beta-crystallin B2 and
vimentin than did normal eye fluids. Our results indicate that LruA and LruB share immuno-relevant
epitopes with
eye proteins, suggesting that cross-reactive antibody interactions with eye
antigens may contribute to immunopathogenesis of Leptospira-associated recurrent
uveitis.