Somatic Diversification of the S107 (T15) VH11 Germ-Line Gene that Encodes the Heavy-Chain Variable Region of Antibodies to Double-Stranded DNA in (NZB × NZW)F1 Mice

A variety of studies suggest that members of the S107 (T15) heavy-chain variable-region gene family contribute to the autoimmune response of mice and humans to DNA. To identify the germ-line gene(s) involved and the degree of somatic diversification that occurs in such autoantibodies, we determined the mRNA sequence of the heavy and light chains of a group of monoclonal anti-DNA antibodies encoded by the S107 VH11 germ-line gene in (NZB × NZW)F1 mice. We also cloned and sequenced the VH11 germ-line gene of the NZB and NZW parental strains. The VH11 coding sequences of the two strains were identical. Comparison with this heavy-chain germ-line sequence showed that the variable regions of the monoclonal antibodies had undergone considerable somatic diversification.