Homologous monoclonal antibodies induce idiotope-specific suppression in neonates through maternal influence and in adults exposed during fetal and neonatal life.

The fine specificity of idiotype suppression induced early in ontogeny was investigated in the murine A/J anti-azophenylarsonate (Ar) response. Suppression was induced with two hapten-inhibitable, homologous monoclonal anti-idiotopic antibodies, AI and MB, that recognize partially overlapping sets of Ar-immune antibodies. Suppression was found to be idiotope-specific when adult mice were exposed to anti-idiotope as neonates; suppression was also idiotope specific when adult mice were exposed to anti-idiotope during fetal (through maternal inoculation) and neonatal life. Of particular interest, anti-idiotope, administered maternally, induced suppression in offspring first immunized with Ar as neonates, and this suppression was idiotope specific too. Thus, AI and MB induce idiotope-specific suppression in mice exposed to anti-idiotope early in ontogeny. These results parallel previous findings in adult mice and suggest that the mechanism of suppression in very young mice is the same as that in adults.