Περίληψη:
Anti-Ro60KD autoantibodies are commonly found in sera from patients with
primary Sjogren’s syndrome (SS) and systemic lupus erythematosus (SLE).
In order to identify the epitopes of this autoantigen, 22-mer, synthetic
peptides overlapping by eight residues, and covering the entire sequence
of the Ro60KD autoantigen were prepared. Three groups of sera were
evaluated according to their autoantibody specificities. The first group
consisted of monospecific anti Ro60KD sera from four patients with SLE
and one with SS, the second one was composed of anti-Ro60KD +
anti-La(SSB)-positive sera from four patients with SS and the third
group included three normal sera and one anti Ro52KD serum. It was found
that sera from SLE patients interact with a common antigenic site
spanning the sequence TKYKQRNGWSHKDLLRSHLKP (169-190) of the Ro60KD
protein. On the other hand, sera from SS patients recognise the
ELYKEKALSVETEKLLKYLEAV (211-232) region of this autoantigen.
Determination of the minimal required peptide length for optimal
antibody recognition showed that the defined epitopes can be shortened
to the NGWSHKDLLR (175-184) and KALSVETEKLLKYLEAV (216-332) sequences
respectively. Inhibition experiments using the Ro60KD antigen and
soluble peptides corresponding to the 175-184 and 216-232 segments
further confirmed the specific antibody binding. These results, although
only a small number of sera were used, indicate that the Ro60KD
autoantigen, which is not characterized by disease specificity, contains
two discrete epitopes specifically recognized from SLE and SS patient
sera. Finally, the sequence similarity of the NGWSHKDLLR (175-184)
epitope with some of the HLA haplotypes, associated with anti-lie
response, deserves to be noted.
Συγγραφείς:
Routsias, JG
Tzioufas, AG
SakarellosDaitsiotis, M and
Sakarellos, C
Moutsopoulos, HM
