Immunological analysis of epitopes on hCG.

The heterodimeric glycoprotein hormone, human chorionic gonadotropin, has been extensively characterized in terms of its recognition by mouse monoclonal antibodies. A number of different approaches have led to the definition of several epitope clusters on the surface of the molecule. These include epitopes located solely on the alpha- or beta-chain, some of which are masked when the two chains associate to form the holo-hormone. Additional epitopes comprise amino acids contributed by both the chains. In contrast to the extensive knowledge regarding B cell epitopes, the characterization of T cell epitopes on hCG has only recently begun to be explored.