Rabbit allotype a locus subspecificities of homogeneous anti‐streptococcal antibodies

Abstract

Rabbits were immunized with group A-variant (Av) streptococcal vaccine to elicit antisera containing antibodies of "restricted heterogeneity" specific for Av polysaccharide. Antibodies that migrated as single bands in polyacrylamide gel isoelectric focusing were isolated on agarose block electrophoresis and preparative isoelectric focusing. These homogeneous antibodies were analyzed for content of the a locus markers by inhibition of allotype-anti-allotype radioimmunoassays. Both single-band preparations and preparations containing 2--5 bands were deficient in content of the a locus markers. These analyses were strongly influenced by the different anti-allotype antisera used. Single-band preparations, deficient in a 2 or a 3 markers, were further used to produce anti-allotype antisera, and these sera were assayed for reaction with pooled a2 or a3 molecules. The results, in contrast to the a1 allotype, failed to demonstrate common determinants on either a 2 or a 3 molecules indicating that each a allotype consists of a set of different Ig molecules. The data suggest different evolutionary pathways of the a 1, as opposed to the a 2 and a 3 molecules.

Regulation of natural antiallotype antibody responses by idiotype network-induced auto-antiidiotypic antibodies.

“…Another important and relevant difference between determinants specified by a and b loci is the marked heterogeneity of the former, which is recognized through the existence of distinct subsets of molecules (25)(26)(27). If, for example, antibody for one subset ofal molecules is deleted from an anti-al serum, then the remaining antibody, even in excess of antigen, will bind only a portion of the al-bearing Ig molecules.…”