Novel functional activities of anti-DNA autoantibodies from sera of patients with lymphoproliferative and autoimmune diseases

DNA-hydrolyzing activity of IgG autoantibodies from sera of patients with v arious types of lymphoproliferative diseases was investigated. The associat ion of DNA-hydrolyzing activity with the antibody (Ab) fraction has been pr oved by newly developed affinity-capture assay. Study of abzyme incidence i n blood tumors and systemic lupus erythematosis (SLE) revealed linkage of a nti-DNA Ab catalysts to mature B-cell tumors, and increased probability of DNA-abzymes formation on the background of autoimmune manifestations. These data suggest possible similarity between mechanisms of abzyme formation in SLE and B-cell lymphomas. A new mechanism of formation of DNA-specific cat alytic Abs has been proposed based on the increased crossreactivity of poly clonal DNA-abzymes to DNA-depleted nuclear matrix proteins. The possibility of the abzyme production as Ab to the energetically destabilized ground st ate of the antigen has been discussed. Preliminary results were obtained th at indicate the complement-independent cytotoxicity of anti-DNA autoantibod ies isolated from blood of patients with SLE and chronic lymphocytic leukem ia.