11 - Idiotypic Specificities of Immunoglobulins

Abstract

This chapter reviews idiotypic specificities of immunoglobulins. Monotypic immunoglobulins, such as myeloma and Bence Jones proteins, and antibody populations from individual animals possess individually specific antigenic determinants. For example, one can prepare an antiserum in a rabbit that when appropriately absorbed will react with the human myeloma protein used as immunogen but, with rare exceptions, not with any other myeloma protein or immunoglobulin. Alternatively, one can immunize a rabbit with antibody from an individual human or rabbit and elicit specific anti-antibodies. The restriction of idiotypic determinants to antibodies of a single specificity from an individual donor clearly differentiates idiotypy from allotypy, as allotypic determinants are shared by various antibodies of an individual. A contribution of the constant region of a polypeptide chain to an idiotypic determinant is conceivable, but idiotypic differences among proteins must reflect differences in the variable regions. Anti-idiotypic antibodies can be prepared against antibodies from an individual donor, despite the heterogeneity of the immunogen.