Induction of immunological tolerance to the chemical carcinogens in early ontogenesis.

It is postulated that the induction of immunological tolerance to chemical carcinogens is due to the penetration of carcinogens and its albumin and DNA adducts from the maternal organism into the embryo. Maternal serum lgG-antibodies to carcinogens promote the transportation of carcinogens and adducts into the embryo through placenta and thus stimulate the tolerance induction. On the contrary, maternal secretory lgA-antibodies to carcinogens protect maternal, embryonal and new-born organisms from environmental carcinogens and thus inhibit the tolerance induction. The low individual maternal secretory lgA/serum lgG ratio leads to the immunological tolerance to carcinogens both in embryos and children.