Presence of an intrastrain cross-reactive idiotype on A/J antibodies of the IgE class specific for the p-azophenylarsonate group.

An intrastrain cross-reactive idiotype, CRIA, is associated with a large proportion of the anti-p-azophenylarsonate (anti-Ar) antibodies of A/J mice. The present experiments, in which the methods of direct and reverse passive cutaneous anaphylaxis (RPCA) were used, indicate that IgE anti-Ar antibodies are produced in A/J mice upon stimulation with a protein-Ar conjugate and that a large proportion of these antibodies express CRIA. The use of monoclonal anti-CRIA for RPCA eliminated the strong nonspecific reactions previously observed. The results provide a basis for studying factors that regulate the switch to IgE biosynthesis during an immune response.