idiotype–anti-idiotype network

a regulatory mechanism mounted in response to the unique or idiotypic determinants of lymphocytes or antibodies upon antigenic stimulation. Activation of a B cell results in a clone of plasma cells producing immunoglobulin of a single idiotype, which, because it was previously present in very small quantities, can be recognized as “nonself” and results in the production of anti-idiotypic antibodies directed against its idiotypic determinants. There can also be anti–anti-idiotypic antibodies directed against the second antibodies, antibodies directed against them, and so forth. These antibodies react with antigen receptors on B cells and T helper and suppressor cells, as well as with circulating antibodies, to enhance or suppress production of the initial antibody by various mechanisms.