IgE isotype suppression in anti-epsilon-treated mice

Two groups of CBA/J mice received a total of eight intraperitoneal (i.p.) injections of heavy-chain-specific rabbit anti-IgE or rabbit gammaglobulin within 48 hr of birth through day 38. A third group of animals was untreated. All mice were subsequently immunized with four i.p. injections of castor allergen plus aluminum hydroxide. Results indicate that anti-treatments severely suppressed murine serum IgE levels as compared with control mice. In addition anti-epsilon-treated mice were initially unable to produce detectable reaginic antibody upon immunization with castor bean allergens (CA). Upon further CA immunization, these animals did produce an IgE antibody response, but this was still lower than that detected in control immunized mice. Other immunoglobulin levels in the anti-epsilon-treated mice were not suppressed as compared with those in the control mice. These results suggest that neonatally administered anti-epsilon antisera selectively diminished total IgE levels as well as antigen-induced IgE antibodies in mice.