Effects of Anti-Idiotypic Sera (Ab-2) and Monoclonal Idiotypic Antibody (Ab-1) on the Immune Response to a Simple Polypeptide Antigen with only Two Immunologically Active Epitopes. Analysis of the Response at the Unideterminant Level

Abstract

It is now well recognized that the specific selection of B cell subclones is mediated by way of cell surface immunoglobulins exhibiting the V domains which that cell is programmed to produce as secretory Ig when it undergoes division and differentiation. Thus, there is no ambiguity in designating Ig as the B cell receptor which as such will exhibit dependence on the molecular configuration of the epitope to which it binds. Although an enormous amount of work has, in the past decade, gone into the elucidation of the molecular properties of the equally specific receptor on the T cell, many questions still remain unanswered. It is not yet clear whether the T cell receptor and the antigen specific factors secreted by subpopulations of T cells constitute the same or distinct molecular species. Although it is generally accepted that V_L markers can be found on T cells, no V_H markers have yet been detected and the role of V_L in antigen recognition has not been clarified. The most definitive work in this area has utilized small haptenic molecules (azobenzene arsonate, NIP, etc.) as antigens rather than the more natural polypeptides. With use of these haptens it has been shown quite convincingly that specific T cells bear idiotypic determinants which react with anti-idiotypic antisera raised against the major idiotypes expressed in the serum of immunized animals.