CENP-O, a protein localized at the centromere throughout the cell cycle, is a novel target antigen in systemic sclerosis.

OBJECTIVE:CENP-A, -B, and -C are major centromere components and the main targets of anticentromere antibodies (ACA). Many other proteins are also assembled around CENP-A nucleosomes in interphase nuclei to form the interphase centromere complex (ICEN). The CENP-O protein is a component of the ICEN that localizes at the centromere throughout the cell cycle. We investigated whether CENP-O is also targeted by sera from patients with systemic autoimmune diseases. METHODS:Sera from 114 patients with ACA and 142 patients without ACA were analyzed. Western blotting and an ELISA with bacterially expressed recombinant CENP-O protein were performed to screen for the presence of anti-CENP-O antibodies. In addition, anti-CENP-O antibody-positive sera were tested by Western blotting HeLa cell extracts to examine reactivity with the major centromere antigens. RESULTS:Four female patients with ACA had anti-CENP-O antibodies. There was no correlation of anti-CENP-O antibodies with specific clinical features or other serological features. However, one of the 4 patients, who showed a unique clinical course of scleroderma, had sera with markedly high reactivity to CENP-O. CONCLUSION:CENP-O protein is a novel centromere antigen that is recognized by a very minor population of ACA-positive patients with scleroderma. Because CENP-O is an ICEN component, ICEN may be a large antigenic structure in systemic autoimmunity.

KEYWORDS: {{ getKeywords(articleDetailText.words) }}