Immunochemical Study of Antigenic Specificity in Delayed Hypersensitivity v. Immunization with Monovalent Low Molecular Weight Conjugates* by Sidney Leskowitz, Ph.d.,

Arsanilic acid conjugated to poorly antigenic carriers was shown to be capable of producing good hapten-specific delayed hypersensitivity but poor haptenspecific antibody production (1). This hapten-specific delayed hypersensitivity was only transiently suppressed by intravenous injections of monovalent conjugates of arsanilic acid and N-acetyltyrosine (2). On the other hand , intramuscular, intradermal, and intraperitoneal injections of such conjugates into newborn guinea pigs produced an unresponsiveness in respect to haptendirected delayed hypersensitivity lasting for many weeks (3). Because of this ability to produce tolerance, it became of interest to determine whether these simple monovalent conjugates could also function as complete antigens in the production of hapten-specific delayed hypersensitivity. The results demonstrate that the azobenzenearsonate (ABA) group conjugated to a variety of simple aromatic compounds is capable of acting as a complete antigen in the production of delayed hypersensitivity but rarely, if at all, in respect to antibody production.