THE IMMUNOLOGICAL CONSEQUENCES OF EXTRAUTERINE DEVELOPMENT OF ALLOGENEIC MOUSE BLASTOCYSTS

Abstract

Repeated transfer of allogeneic blastocysts to extrauterine sites of male mice results in (1) the progressive diminution and, in some cases, total inhibition of blastocyst development, and (2) the prolonged survival of challenge grafts of skin taken from the strain donating the blastocysts. Syngeneic blastocysts subsequently transplanted to these mice also failed to develop normally, thereby leading to the conclusion that the recipient mice had become immunized against embryo specific (trophoblast?) antigens. The extended survival of the allogeneic skin grafts is probably due to the “extrauterine pregnancies” which are inducing a state of immunological enhancement. A similar condition is known to follow normal intrauterine pregnancy.