Open AccessEpitope‐specific recognition of type II collagen by rheumatoid arthritis antibodies is shared with recognition by antibodies that are arthritogenic in collagen‐induced arthritis in the mouse
Author(s) -
Burkhardt Harald,
Koller Tobias,
Engström Åke,
Nandakumar Kutty Selva,
Turnay Javier,
Kraetsch Hans G.,
Kalden Joachim R.,
Holmdahl Rikard
Publication year - 2002
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.10472
Subject(s) - epitope , autoantibody , type ii collagen , autoimmunity , arthritis , antibody , immunology , rheumatoid arthritis , monoclonal antibody , medicine , autoimmune disease , epitope mapping
Objective To analyze the fine specificity of IgG autoantibodies in sera from rheumatoid arthritis (RA) patients for type II collagen (CII) epitopes that are arthritogenic in collagen‐induced arthritis (CIA), a relevant murine model of RA. Methods For enzyme‐linked immunosorbent assay (ELISA) analysis of conformation‐dependent autoantibody binding, recombinant chimeric collagens that harbor the respective CII epitopes as an insertion within the frame of a constant type X collagen triple helix were constructed. In addition, synthetic peptides mimicking the native collagen structures were applied for the first time in the ELISA assessment of humoral CII autoimmunity. Results The pathogenicity of IgG responses to certain CII determinants in CIA was demonstrated by arthritis development in BALB/c mice upon the combined transfer of 2 mouse monoclonal antibodies specific for precisely mapped conformational CII epitopes (amino acid residues 359–369 [C1 III ] and 551–564 [J1]), whereas antibodies to another epitope (F4) were not arthritogenic. To test whether human autoimmune responses are similarly directed to these conserved CII determinants, serum IgG was analyzed. The prevalence of sera with increased IgG binding to the C1 III epitope was significantly higher in RA compared with sera from healthy donors or from patients with other rheumatic conditions, e.g., osteoarthritis (OA), systemic lupus erythematosus (SLE), or relapsing polychondritis (RP), whereas levels of antibodies specific for the nonarthritogenic F4 epitope were associated with OA rather than RA. Conclusion Autoimmunity to CII, although detectable in different rheumatic conditions, differs in fine specificity between distinct disease entities. In RA, in contrast to degenerative joint disease, RP, and SLE, autoantibody responses are directed to an evolutionary conserved CII structure that is also targeted by pathogenic autoimmune responses in murine models of arthritis.