Idiotypic mimicry of a cell surface DNA receptor: evidence for anti‐DNA antibodies being a subset of anti‐anti‐DNA receptor antibodies

SUMMARY Anti‐idiotypic anti‐DNA antibodies (anti‐anti‐DNA) have previously been described in both patients with systemic lupus erythematosus and healthy individuals. Jerne's hypothesis predicts that such antibodies would bear a paratope reactive with non‐sequence specific DNA binding proteins. Here we have explored the notion of a molecular mimicry between anli‐anti‐DNA antibodies and antibodies to a previously described 28–29 kD cell surface DNA binding molecule. It was shown that affinity purified anti‐anti‐DNA antibodies inhibit the binding of DNA to cells and that MoAb to the 28–29 kD receptor react with anti‐DNA antibodies. These findings indicate that a subset of anti‐anti‐DNA antibodies are idiotypically related to antibodies reactive with a cell surface DNA binding molecule. It is hypothesized that anti‐DNA antibodies may arise when a convergence of genetic and environmental influences favours an unrestrained anti‐idiotypic response to cell surface DNA binding molecule(s).