Maternal determinants of neonatal immune response to ovalbumin: effect of breast feeding on development of anti-ovalbumin antibody in the neonate.

Inbred Brown-Norway female rats were immunized intraperitoneally with ovalbumin (OVA) or sham-immunized 14 days before and 10 days after mating. In subsequent studies with OVA, babies fed by immunized mothers, regardless of whether they were born from immunized or sham-immunized mothers, showed suppression of IgG, IgM and IgE anti-OVA responses. In additional studies, these babies developed OX-8-positive but W3/25-negative phenotypic suppressor T-cells specific for anti-OVA antibody production. However, these regulatory cells did not react with OVA itself when tested for in vitro proliferative response to OVA. Subsequent immunization of the neonates with OVA appeared to abrogate suppression of IgG and IgM antibody responses. However, maternally induced suppression of IgE persisted and was not influenced by subsequent immunization.