Monoclonal antibodies to the acetylcholine receptor by a normally functioning auto-anti-idiotypic mechanism

Abstract

Recently we described a procedure for preparing antibodies to the acetylcholine receptor (AChR) based on immunoglobulin idiotypes and on the hypothesis that, regardless of functional differences, macromolecules of the same specificity will show structural homologies in their binding sites. Antibodies were prepared in rabbits to a structurally constrained agonist of AChR, trans-3,3'-bis[alpha-(trimethylammonio)methyl]azobenzene bromide (BisQ). These antibodies mimicked the binding specificity of AChR in its activated state--agonists were bound with affinities that were in accord with their biological activities and antagonists were bound poorly. Rabbits were then immunized with a specifically purified preparation of anti-BisQ to elicit a population of antibodies specific for the binding sites of anti-BisQ. A portion of the anti-idiotypic antibodies produced in the second set of rabbits cross-reacted with determinants on AChR preparations from Torpedo californica, Electrophorus electricus and rat muscle. Moreover, several of the rabbits showed signs of experimental myasthenia gravis, in which circulating AChR antibodies are typically found. To devise a more direct route to monoclonal anti-receptor antibodies we based our strategy on acceptance of the concept of the anti-idiotypic network theory of Jerne. According to this theory, injection of an antigen elicits, in addition to antibodies to the antigen, other populations that include anti-idiotypic antibodies directed at the combining sites of the antigen-specific antibodies. If the antigen-specific antibodies recognize a ligand of a receptor, then the anti-idiotypic antibodies should bind receptor. Thus, when a mouse is immunized with a bovine serum albumin conjugate of BisQ (BisQ-BSA), it should be possible to expand populations of spleen cells that secrete antibodies which bind anti-BisQ and AChR, in addition to populations specific for BisQ. Fusion of the spleen cells with an appropriate myeloma line should yield monoclonal anti-AChR antibodies. Here we report the success of this approach and its implications.

Anti-idiotypic antibodies as probes of protein active sites: application to cholera toxin subunit B.

“…The strategy for the preparation of monoclonal anti-IdAb follows Cleveland et al (19). Eight-week-old female'BALB/c mice were immunized i.p.…”

Crime and Punishment in the Society of Lymphocytes: A Speculation on the Structure of the Putative Idiotypic Network

“…Experimental evidence for auto-anti-Ids is sparse, but most studies have depended on serological methods (61). Very recent studies using mono clonal antibody technology suggest that auto-anti-Ids are readily detectable (62)(63)(64)(65)(66) Since the mechanism of symmetrical stimulation is antibody dependent, it is necessary to consider the possible breaking of symmetry by S-antigens in cases where Id or anti-Id has an anti-S specificity. It will be recalled that the breaking of symmetry by S-antigens is a crucial factor in the an tagonism of Id-anti-Id pairs.…”

Glucose transport protein is structurally and immunologically related to band 3 and senescent cell antigen.

“…According to the anti-idiotypic network theory of Jerne (32), injection of an antigen elicits antibodies to the antigen and, in addition, anti-idiotypic antibodies directed at the antigen-combining site (Fab hypervariable region) of the antigen-specific antibodies. It has been shown that production of antigen-specific antibodies against a ligand of a receptor results in anti-idiotypic antibodies that bind to the receptor itself (24,33,34). For example, immunization with insulin results in the production not only of antibodies to insulin (idiotypes) but also of antibodies that recognize the insulin receptor (anti-idiotypes) which are produced against the anti-insulin antibodies (35,36).…”