Suppression of delayed hypersensitivity by antigen and antibody

摘要

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.The data concerning delayed hypersensitivity to SRBC in the rat were in some ways analogous to previous findings concerning induction of haemolytic plaque-forming cells to SRBC in the same animal. The interpretation that delayed hypersensitivity and humoral antibody formation could represent alternative responses of potential antibody-forming cells to immunological induction was considered.