The induction of delayed hypersensitivity by macrophage-associated antigen. The role of macrophage cytophilic antibody.

Abstract

The regulation of the immune responses by antibody administered passively on peritoneal exudate cells (PEC) was studied in guinea-pigs. The immunogenicity of sheep red blood cells (SRBC) associated with PEC for the induction of delayed hypersensitivity (DH) to soluble erythrocyte antigen was enhanced when PEC were incubated with anti-SRBC antibody. In contrast, the antibody response to SRBC was depressed. This phenomenon was only observed with specific antibody and was partially blocked when PEC covered with anti-SRBC antibody were incubated with rabbit anti-guinea-pig globulin serum. Comparable amounts of anti-SRBC antibody injected separately had no enhancing effect. Anti-SRBC sera from which the cytophilic antibody activity had been removed were inactive. PEC-associated SRBC were usually more immunogenic than the same amount of `free' SRBC for the induction of delayed hypersensitivity and always more immunogenic for antibody production.