Antigen binding characteristics of antibodies induced against nitric oxidemodified plasmid DNA

Nitric oxide (NO) generated by the reduction of sodium nitrite with sodium dithionite caused damage to plasmid Bluescript DNA leading to strand breaks and base modifications. The NO-plasmid DNA was highly immunogenic in rabbi ts, The antibody activity was inhibited to the extent of 86% with the immun ogen as inhibitor, indicating the induction of immunogen specific antibodie s. However, delineating the antigenic specificity of anti-NO-plasmid DNA an tibodies by competition ELISA, multiple cross-reactivity was observed. The antibodies recognised B-, A- and allied conformations. The visual detection of immune complex formation with native and NO-plasmid DNA reiterated pref erential binding with modified plasmid DNA. DNA modified by nitric oxide pr esents unique epitopes. which may be one of the factors in antigen-driven a utoimmune response in systemic lupus erythematosus. (C) 2001 Elsevier Scien ce B.V. All rights reserved.