Specific Homograft Tolerance Induced by Successive Matings and Implications Concerning Choriocarcinoma2

Abstract

Immunologic tolerance to the male antigen(s) in C57BL/An mice was induced in adult females of this strain by repeated matings with C57BL/An males. The tolerance was demonstrated by successful skin grafts from male donors to the females. The degree of tolerance was roughly proportional to the number of prior pregnancies. A partial tolerance may also have been induced by matings with sterile males. The observation that specific immunologic tolerance can be produced by successive matings of appropriate specificity offers an experimental model for explaining the apparent association of parity with the incidence of human choriocarcinoma and the apparent rarity of human erythroblastosis fetalis.