History of Reproductive Immunology:Nobel Prize

I thought it would be interesting to discuss briefly what started reproductive immunology and how the early scientists figured out the significant contribution the immune system plays in accepting the "fetal allograft"

Medewar and his associates back in the 1940's discovered when mice were pregnant they never rejected transplants of any tissue from the male that got them pregnant. whether it was skin graft or other organ transplant they did not reject it , even though the male partner did not match their genetics in any way. Its also interesting that they did reject all other transplants from other males showing that they only became "tolerant" to their partners genetics while pregnant and no other males.

After the pregnancy was over, they went back to rejecting the grafts from the male partner.

Medewar undestood that the only explanation for this (and he of course was right) was that the pregnancy itself did something to make the mothers immune system accept the husbands genitics(i.e. those genetics that the mother was exposed to from the male genetics on the embryo), and that this ability to accept those genetics ends when the pregnancy ends.

What we know today and they didnt know then is that the development of the T regulator cells(those T cells that are developed during the pregnancy) turns off all the immune response to the paternal(fathers genetics) only during the pregnancy, allowing the pregnancy to survive(when all is working ok) and for the mother to accept transplants from the father (but only while she is pregnant).

This is what started the research that has brought the field to where we know it today.,!!! It won the Nobel Prize.