Immunological studies of mouse decidual cells. I. Membrane markers of decidual cells in the days after implantation.

Mouse decidual cell suspensions from day 6 to day 8 of gestation were prepared by enzymatic treatment with collagenase and trypsin and tested for various membrane markers. (a) Besides H-2 antigens, Thy-1 antigens are present on about 50% of the cells; this may reflect the fibroblastic origin of decidual cells or be a marker expressed on some decidual cells possibly under hormonal control. (b) T or B lymphocytes, as defined by four Lyt antigens or surface immunoglobulins, are not present in significant amounts. (c) A substantial number of cells bearing receptors for the Fc portion of IgG (FcR) is detectable in the decidua, probably closely connected with trophoblast cells; these FcR-bearing cells may act in preventing excessive invasion of uterine tissue by trophoblast or could contribute to the protection of the embryo by interacting with maternal blocking antibodies and trophoblast. No receptors for for complement were detected, even after 16-20 h in culture after trypsin treatment.