Auto-antibody to an Ig VH region allotype: induction of anti-a1 antibody in an a1-suppressed a1a2 heterozygous rabbit.

Two a1a2 heterozygous sibling rabbits were first suppressed for the paternally inherited a1 VH region allotype and then immunized with a1 IgG. Anti-a1 antibody was detected in the serum of one of the rabbits. The anti-a1 auto-antibody reacted with the same amount of a1 IgG as did a conventional anti-a1 allo-antibody. Most of the IgG and IgM of this rabbit was of the a2 allotype and no significant amount of the a1 allotype was detected as would be expected for an a1 suppressed a1a2 heterozygous rabbit. However, allotype suppression in this rabbit is maintained by endogenous anti-allotype antibody. Rabbits with anti-allotype auto-antibody may be exploited to produce litters of heterozygous and homozygous rabbits efficiently suppressed for selected allotypes.