• Immune suppression;
  • nucleated chicken erythrocytes;
  • maternal influence;
  • passive antibody

ABSTRACT: Effects of immunization of pregnant AKR mice with nucleated chicken erythrocytes (CRBC) on immune responses of their offspring were examined. Antigen-specific reduction of generation of cytotoxicity and plaque forming cells (PFC) was demonstrated in the offspring at 8 weeks after birth, and lasted for 15 weeks. Cross-fostering experiments and cell transfer experiments showed that such suppression would be induced by antibody contained in the milk of immunized mothers rather than suppressor cells. Activities to enhance opsonization and to mediate antibody-dependent cell-mediated cytotoxicity (AI)CC) were demonstrated in the serum of such offspring before challenge with CRBC. Delayed footpad reaction (DFR) was maintained at the normal level in such offspring of immunized mice.