Blocking of the Lymphocyte Antigen Receptor Site with Anti-immunoglobulin Sera in vitro

Abstract

ALTHOUGH the events occurring during the induction of an antibody response are not clearly understood, it is evident that antigen must react with some type of receptor which is either free in serum or present at a cell surface. Various experiments^1–3 in which labelled antigen is allowed to react in vitro with lymphocytes suggest that a very small proportion of all lymphocytes does in fact have the ability to recognize and bind a given antigen. The specificity of this binding reaction between antigen and lymphocyte was demonstrated in both adoptive transfer experiments⁴ and in vivo³. Electron microscopic studies indicate that the reactive lymphocytes possess localized receptor sites for antigen on their surface⁵. Preliminary studies² showed that pretreatment of these cells with a polyvalent anti-immunoglotaulin serum inhibited antigen binding and suggested that the antigen receptor site involves some type of immunoglobulin molecule. We now report in more detail on the nature of the receptor sites on lymphocytes and suggest that interaction of antigen with these sites is crucial in the induction of the antibody response.