Suppression of delayed hypersensitivity by antigen and antibody. Is a common precursor cell responsible for both delayed hypersensitivity and antibody formation?

Abstract

Delayed-type hypersensitivity and antibody formation to sheep erythrocytes (SRBC) was studied in rats. Two immunologically specific suppressive effects on the primary induction of delayed hypersensitivity were found: one was short-lasting and due to a direct action of intravenous antigen; the other was mediated by anti-SRBC antibody and demonstrable both as a later-occurring and indirect effect of active immunization and as occurring consequent to passive immunization. Either of these two forms of suppression only partially prevented primary induction of delayed hypersensitivity, but used together their effects were synergistic and completely suppressed development of delayed hypersensitivity. The secondary delayed hypersensitivity response was insusceptible to antibody inhibition.