Idiotypes on Galactan Binding Myeloma Proteins and Anti-Galactan Antibodies in Mice

Abstract

Antibodies with specificity for β1,6 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), β1,6D-galactan binding myeloma proteins (β6GALBMP). Two kinds of idiotypic sera were obtained: cross-specific sera that reacted with two or more β6GALBMP but not other BALB/c myeloma proteins, and individual idiotypic sera that reacted with only the β6GALBMP used in the immunization. Antibodies with specificity for β1,6 linked D-galactans shared cross-specific idiotypes with β6GALBMP. Only one of seven individual idiotypes associated with β6GALBMP was found on galactan antibodies. Since all β6GALBMP thus far have the same V_k and V_H isotype 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.