The common idiotypic specificity of anti-a2 allotype antibodies: contribution of H and L chains to idiotype expression

Abstract

Previously an idiotypic specificity common to anti-a2 allotype Ab from 15 rabbits was detected and characterized. The contribution of H and L chains to the expression of this common idiotypic specificity was determined. Two types of recombinant IgG were prepared: (1) H chains from anti-a2 Ab with L chains from normal a3b4 IgG. and (2) L chains from anti-a2 Ab with H chains from normal a3b4 IgG. By inhibition of binding radioimmunoassay, recombinant IgG having either H or L chains from anti-a2 did not inhibit the binding between anti-a2 Ab and anti-idiotype Ab. By direct binding radioimmunoassay, recombinant IgG of H chains from anti-a2 Ab with L chains from a3b4 IgG reacted with anti-idiotype Ab whereas recombinant IgG with H chains from normal a3b4 IgG and L chains from anti-a2 Ab did not react. These results indicate that the common idiotypic specificity of anti-a2 Ab is determined primarily by the H chain; however, the full expression of the common idiotypic specificity requires the interaction of both H and L chains from anti-a2 Ab.