Inhibition of the Development of Delayed Hypersensitivity by Treatment with Antiserum

Abstract

Daily i.p. injections in mice of homologous or heterologous antiserum to chicken ovalbumin performed during the period of initial sensitization specifically suppressed development and hastened waning of immediate and delayed hypersensitivities to this antigen. This suppressive effect was considerably more effective against delayed hypersensitivity than against immediate. Intensive antiserum treatments usually were employed to elicit this type of suppression, but it could be induced with as little as 1.2 µl of antiserum given in 12 daily equal aliquots, or by a single injection of nonisogenic immune lymphoid cells. Immunologic suppression by antiserum treatments affects production of antibodies but does not interfere with the initial events of antigen recognition necessary for development of anamnestic responsiveness. These findings indicate that although immediate and delayed hypersensitivities may be different mechanistically they cannot be considered independent of each other, for the presence or absence of one can influence development of the other. The implications of this conclusion for interpreting such general phenomena as antiseruminduced resistance to autoimmune diseases, immunologic enhancement, the pathogenesis of certain infectious diseases, tolerance and mechanisms of adjuvant activity are discussed.