Epitope mapping on Wegener's granulomatosis autoantigen proteinase 3.
OBJECTIVE
To map the epitopes on Wegener's granulomatosis autoantigen proteinase 3.


METHODS
Antigenicity of proteinase 3 was studied with Western blot analysis in which proteinase 3 was prepared under reducing and non-reducing conditions. Two anti-proteinase 3 monoclonal antibodies, HZ1F12 and HZ1H3, were used to inhibit each other and to inhibit 22 anti-proteinase 3 positive sera from patients with Wegener's granulomatosis in competitive inhibition enzyme-linked immunosorbent assays (ELISA) and Western blot analysis.


RESULTS
All monoclonal antibodies and patient sera recognized proteinase 3 under non-reducing conditions in Western blot analysis. ZH1F12 was inhibited 74% by HZ1H3. 10/22 (46%) sera were completely or partially inhibited by HZ1F12; 9/22 (41%) sera were partially inhibited by HZ1H3; and 6/22 (27%) were inhibited by both monoclonal antibodies. In inhibition Western blot analysis, the binding of patient sera to proteinase 3 could be inhibited by HZ1F12.


CONCLUSIONS
The epitopes of Wegener's granulomatosis autoantigen were conformational. Anti-proteinase 3 monoclonal HZ1F12 and HZ1H3 recognized similar or overlapping epitopes on the proteinase 3 molecule. Epitopes of proteinase 3 recognized by anti-proteinase 3 positive sera were not restricted.
Huang
Z
Z
Department of Physical Medicine and Rehabilitation, First Medical School, Beijing Medical University, Beijing 100034, China.
Lockwood
C M
CM
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D014890:Granulomatosis with Polyangiitis / Q000276:immunology*; D006801:Humans; D051379:Mice; D053146:Myeloblastin; D012697:Serine Endopeptidases / Q000276:immunology*
D000911:Antibodies, Monoclonal; D001324:Autoantigens; D012697:Serine Endopeptidases; D053146:Myeloblastin