Insoluble DNA-like phosphorylated polystyrene: specific interactions with anti-DNA antibodies from systemic lupus erythematosus patients

Abstract

Systemic lupus erythematosus (SLE) is an autoimmune disease. Antibodies directed mainly against DNA and/or phospholipids are present in the serum of SLE patients. Therefore phosphorylated polystyrene derivatives acting as DNA-like polymers should be able to interact with the SLE anti-DNA antibodies. Such functional polymers were synthesized and subsequently their interactions with the anti-DNA antibodies studied. Adsorption experiments performed with both anti-DNA antibodies and normal immunoglobulins showed high affinity constants of the phosphorylated polymer for anti-DNA antibodies (4 × 10 9 M −1) whereas for normal IgG the affinity was low (2 × 10 5 M −1). Moreover, the interaction was specific involving the idiotypic moiety of the anti-DNA antibodies and an array of phosphoester groups at the surface of this biomaterial.