La tolérance immunologique fœto-placentaire

Embryo implantation in uterine mucosa is the same phenomenon as an allogenic tissue graft, involving complex tolerance mechanisms developed in the maternal tissue. Foetal trophoblasts and uterine mucosa are the principal actors of tolerance phenomenon. Non classical HLA-G antigen expressed on trophoblast cells and CD56+CD16- Natural Killer cells (NK cells) are directly involved to maintain tolerance together with cytokines secreted by decidual cells and trophoblast. In this article, we describe the immunological cellular and biochemical mechanisms involved in foeto-maternal tolerance, essential for embryo survival.