A Mouse Monoclonal Antibody Against Rabbit VH Allotype Shares the Predominant Idiotype with a Rabbit Antibody of the Same Specificity

A monoclonal antibody, termed 3-2F1, is specific for the rabbit VH al allotypic marker. This antibody appears to recognize a common al determinant since it reacts with all of the a1 immunoglobulin (Ig) that is bound by polyclonal rabbit anti-a1, and completely inhibits the binding of polyclonal anti-a1 to a1 Ig. When tested for the predominant IdX-a1 idiotype previously shown to be expressed on virtually all rabbit anti-a1 antibody, it was found that 3-2F1 also bears this idiotype. In fact, sequential absorption and inhibition assays indicate that 3-2F1 displays the entire set of rabbit IdX-a1 determinants. The results are consistent with the concept that the anti-IdX reagent bears a latent internal image of the common VH a1 epitope.