Abstract | OBJECTIVE: METHODS:
PCNA complexes were purified from rabbit thymus extract by affinity chromatography using anti- PCNA monoclonal antibodies (TOB7, TO17, and TO30); monomeric and trimeric PCNA forms (AK- PCNA) were purified using anti- PCNA serum AK. The reactions to these antigens of 10 anti- PCNA-positive and 40 anti- PCNA-negative sera selected from 560 lupus patients were tested by immunoblotting, immunoprecipitation, and enzyme-linked immunosorbent assays (ELISAs). RESULTS: With one exception (serum OK), anti- PCNA-positive sera reacted exclusively with only the 34-kd polypeptide. In contrast, 14 of 40 anti- PCNA-negative sera reacted with multiple proteins within PCNA complexes. Most anti- PCNA-positive sera probably recognize as epitopes the binding sites for other proteins on PCNA, which are likely hidden when PCNA is complexed with other proteins. As a consequence, only serum OK reacted with the PCNA complex in a series of ELISAs. Using AK- PCNA as a competitive inhibitor, it was determined that serum OK reacts with both the 58-kd polypeptide and the 34-kd PCNA within complexes. Together with the results of a longitudinal analysis, these results suggest that the immune system of patient OK likely recognized the complexed PCNA protein, after which the autoimmune response spread to other elements of the complexes. CONCLUSION: Intermolecular-intrastructural help, leading to the spread of autoimmune response from PCNA to other proteins associated with its biologic function, plays a crucial role in the induction of the autoimmune response seen in lupus patients.
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Authors | Toshiaki Kogure, Yoshinari Takasaki, Ken Takeuchi, Hirofumi Yamada, Masuyuki Nawata, Keigo Ikeda, Masakazu Matsushita, Ran Matsudaira, Kazuhiko Kaneda, Katsutoshi Terasawa, Hiroshi Hashimoto |
Journal | Arthritis and rheumatism
(Arthritis Rheum)
Vol. 46
Issue 11
Pg. 2946-56
(Nov 2002)
ISSN: 0004-3591 [Print] United States |
PMID | 12428236
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Antibodies, Monoclonal
- Proliferating Cell Nuclear Antigen
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Topics |
- Antibodies, Monoclonal
- Autoimmunity
(immunology)
- Enzyme-Linked Immunosorbent Assay
- Epitope Mapping
- Humans
- Immunoblotting
- Lupus Erythematosus, Systemic
(immunology)
- Precipitin Tests
- Proliferating Cell Nuclear Antigen
(immunology)
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