Failure of suckling to transfer immunity to a syngeneic rat sarcoma.

Young born to and suckled by mothers rendered immune to a syngeneic sarcoma showed no acquired resistance to challenge with tumour. Whilst other workers had found that allograft immunity could be transferred by milk, we conclude (1) that lymphocytes present in the milk cannot transfer immunity to tumour-specific antigens when absorbed by suckling, and (2) that transfer of maternal immunoglobulins either pre- or postnatally also does not protect against s.c. inoculated tumour.