Idiotypes on galactan binding myeloma proteins and anti-galactan antibodies in mice.

Antibodies with specificity for beta1,6 linked D-galactoses were induced in mice by immunization with gum ghatti. Idiotypic antisera were prepared in rabbits and mice by immunization with 8 BALB/c IgA(k), beta1,6D-galactan binding myeloma proteins (beta6GALBMP). Two kinds of idiotypic sera were obtained: cross-specific sera that reacted with two or more beta6GALBMP but not other BALB/c myeloma proteins, and individual idiotypic sera that reacted with only the beta6GALBMP used in the immunization. Antibodies with specificity for beta1,6 linked D-galactans shared cross-specific idiotypes with beta6GALBMP. Only one of seven individual idiotypes associated with beta6GALBMP was found on galactan antibodies. Since all beta6GALBMP thus far have the same Vk and VH isotope composition the results indicate an extensive heterogeneity among galactan-binding immunoglobulins in BALB/c mice. It is speculated that some of this diversity may arise from somatic rather than germ line gene mutations.