MOLECULAR CHARACTERIZATION OF ANTI-DNA ANTIBODIES INDUCED IN NORMAL MICE BY IMMUNIZATION WITH BACTERIAL-DNA - DIFFERENCES FROM SPONTANEOUS ANTI-DNA IN THE CONTENT AND LOCATION OF V(H) CDR3 ARGININES

Immunization of normal mice with bacterial DNA induces a significant a nti-DNA response that includes antibodies resembling some lupus anti-D NA in their binding properties, although lacking specificity for mamma lian dsDNA. To determine the structure of these induced antibodies and their relationship to anti-DNA from lupus mice, we have characterized the clonality and selected V-region sequences of a panel of 20 anti-D NA antibodies from 3 BALB/c mice immunized with ssDNA from Escherichia coli. Southern blot analysis of H and L chain rearrangements indicate d that two of the animals expressed pairs of clonally related antibodi es. Amino acid sequences of 10 of the induced antibodies demonstrated predominant utilization of J558 family V(H) genes and J(H)4 in associa tion with various D(H), Jkappa and Vkappa genes. Among the V(H) CDR3 o f these 10 antibodies, 4 displayed arginine residues as a result of N region additions. None of these antibodies, however, had more than one arginine residue in V(H) CDR3 nor arginines at positions 100 or 100a, characteristic features of lupus antibodies to dsDNA. These results s uggest that normal mice immunized with bacterial DNA display certain f acets of DNA Ag drive, although lacking the mechanisms for the product ion of antibodies to mammalian dsDNA.