Molecular mimicry of parasite antigens using anti-idiotypic antibodies.

Abstract

Current interest in the molecular mimicry of microbial, transplantation, and tumor antigens using anti-idiotypic (anti-Id) antibodies is theoretically grounded in Jerne’s network model (1974), which argues the following: The antigen- combining site, designated paratope, of every antibody molecule recognizes the idiotope of some other antibody molecule. This requires that external (non- immunoglobulin) epitopes and internal idiotopes must be largely overlapping, since they are each recognized by the same set of paratopes. Therefore, for each foreign epitope there must be an idiotope which bears its internal image. In order to obtain antibody molecules which bear epitope-related conformational structures, the strategy has been to immunize with antibody molecules, designated Abl, expressing a paratope for a given epitope, with the intent of inducing a population of antibodies, designated Ab2, some of which share with the epitope a complementary structure to the Abl paratope (Fig. 1). This subpo- pulation of paratope-induced, anti-Abl antibodies has been termed Ab2β, to distinguish it from the more classically considered population pf anti-Id antibodies, termed Ab2α, which are induced by Abl idiotopes and therefore lack any epitope-related structures (Jerne et al. 1982). Assuming that the interaction with receptors through either their paratopes or idiotopes can provide identical signals to the cells which bear them, then both Ab2 populations should be induced by Abl.