Antigenic competition in vitro between heterologous erythrocytes

Abstract

The phenomenon of antigenic competition between different heterologous red cells has been studied in vitro using the Mishell‐Dutton technique of cultivating mouse spleen cells. If spleen cells from animals heavily pre‐immunized in vivo against one antigen are cultured together with this antigen and a second antigen, the antibody response against the second antigen is depressed. The number of antigen sensitive cells was found to be normal during antigenic competition. Competition is transferrable from one population of lymphoid cells to another. Thus, heavily preimmunized cells cultivated in the presence of normal cells suppressed the antibody response of the latter. However, no soluble mediator of this suppression could be recovered from media of cultures displaying antigenic competition or from the serum of animals the spleens of which showed antigenic competition in vitro. A thymus‐independent antigen could not give rise to antigenic competition, but the response to such an antigen was subjected to competition. The finding suggests that intensive specific stimulation of lymphoid cells under thymic influence causes expression of antigenic competition. The phenomenon could either be due to a production of inhibitory factors active over a short distance, only, or to a direct inhibitory cell‐to‐cell interaction between antigen‐activated cells and precursor cells for antibody production.