CHARACTERIZATION OF SOMATICALLY MUTATED S107 VH11-ENCODED ANTI-DNA AUTOANTIBODIES DERIVED FROM AUTOIMMUNE (NZB X NZW)F1 MICE

We have studied 19 S107 heavy chain variable region gene (V(H)11)-encoded monoclonal antibodies from NZBWF1 mice. These studies show that a single V(H) gene can encode both antibodies to foreign antigens (anti-phosphorylcholine) and to self antigens (anti-double-stranded DNA) in the same animal. All of the anti-DNA antibodies contain many somatic mutations compared with the relevant germline genes. Since the anti-DNA antibodies were extensively somatically mutated and had undergone isotype switching, the response seems to be T cell dependent. While some of the antibodies appear to be the products of an antigen-driven and antigen-selected response, a number of characteristics of the antibodies suggest that forces other than antigen are contributing to the stimulation and selection of this response.