CROSS-REACTIVITY OF ANTI-DNA ANTIBODIES WITH PROTEOGLYCANS

Abstract

Ten sera of patients with systemic lupus erythematosus (SLE) were tested in an enzyme linked immunosorbent assay [ELISA] for their ability to react with glycosaminoglycans, constituents of proteoglycans, in relation to their anti-DNA reactivity. The SLE sera reacted with hyaluronic acid and chondroitin sulfate, and this reactivity correlated with the anti-DNA activity of these sera. Sera obtained from patients with other autoimmune diseases or normal sera lacked any of these reactivities. Anti-DNA antibodies purified by affinity chromatography with either oligo DT cellulose or Cibracon blue F3Ga Sepharose reacted with DNA as well as with hyaluronic acid. The cross-reactivity of anti-DNA antibodies was confirmed by the reaction of a mouse monoclonal anti-DNA antibody with DNA, hyaluronic acid and chondroitin sulfate. This pattern of cross-reactivities of anti-DNA antibodies suggests that several compounds can function as antigenic targets for these antibodies provided that their structures contain repeating negatively charged groups.