Immune responses to DNA in normal and aberrant immunity

Because of structural microheterogeneity, DNA can exert powerful effects th at lead to immune system activation as well as antibody induction. These ac tivating effects resemble those of endotoxin and result from sequences that occur much more commonly in bacterial DNA than in mammalian DNA. In contra st, mammalian DNA can inhibit the response to bacterial DNA as well as othe r stimuli and may serve a counterregulatory role during infection. The reco gnition of the immune effects of DNA is relevant to the pathogenesis of a v ariety of infectious and inflammatory diseases including systemic lupus ery thematosus, a prototypic autoimmune disease characterized by anti-DNA autoa ntibodies.