They were obtained by ttyptic digestion of villous tissue from term placentae of 15 healthy women and purified on a Percoll gradient. Contaminating cells were selectively removed by employing a monoclonal anti-HLA class-I antibody. The remaining cells stained with PKKr and anti-transferrin receptor antibodies and exhibited the structural and phenotypical characteristics of intermediateand syncy-tiotrophoblasts. The mean glycogen content of the cells cultured in D-MEM with 5.5 mu glucose was 17.7 + 3.2 pg/mg protein; it remained constant from day 1 to day 4 and was unaltered by higher medium glucose concentrations (17 mu; 28 mu). Between 2-5 h after a medium change, the cells contained 50 per cent more glycogen than at the time of replacement. Short term (O-5 h) as well as long-term incubations (24 h) with both pathological (lo-* M) and physiological (1 O-” M) concentrations of insulin had no influence, with respect either to the rate of increase of glycogen or to the maximum level. We conclude that the glycogen content of isolated syncytiotrophoblasts in vitro is invariant to extracellular glucose concentrations and is not regulated by insulin. This suggests that cells other than syncytiotrophoblasts and their immediate precursors account for the reported alterations of glycogen content in normal human term placenta in vitro under hyperglycemic or hyperinsulinemic conditions.
IMMUNOHISTOCHEMICAL STUDY OF HUMAN DECIDUA J. Died, H.-P. Horny, P. Ruck, K. Marzusch, E. Kaiserling & E. Kabelitz (Department of Obstetrics/Gynaecology and Pathology, University of Tiibingen and Department of Immunology, University of Heidelberg, Germany) Lymphoreticular cells in decidual tissue obtained from 12 patients undergoing therapeutic abortion of an intact pregnancy at 6-10 weeks gestation were investigated in this study. Immunophenotypingwith a broad panel of monoclonal antibodies revealed various subpopulations of lymphoreticular cells. Macrophages (Ki-M6+, Ki-M7+, Ki-MS+, KPl +, Mac 387+ and Ki-MlP+) represented the largest fraction ofintradecidual lymphoreticular cells. The majority of the intradecidual lymphoid cells exhibited an unusual phenotype (CD7+, CD2+, CD56+, triple negative [CD3-, CD4-, CDS-]). The distribution of these unusual lymphocytes mirrored that of the so-called endometrial stromal granulocytes. A few of these stromal granulocytes reacted with the macrophage-associated antibody KPl, but not with Ki-MlP another macrophage marker. This was confirmed by immuno-electron microscopy. The finding that intradecidual CD3 + lymphocytes express neither the o/P nor the ,u/6 heterodimer of the T cell antigen receptor (TCR) was unexpected. However, these cells did express the a/P heterodimer after in vitro culture with PHA-P and recombinant exogenous interleukin 2 (IL-2). No stimulated T lymphocytes expressing activation antigens could be detected. B lymphocytes, T and B immune accessory cells and CD15+ granulocytes were found only in small numbers or were absent. Among cells expressing NK cell markers, CD57-t and CD16+ cells were found in small to moderate numbers, while CD56+ cells were detected in large numbers. It is suggested that down-modulation/regulation of the TCR on CD3 + intradecidual T cells may contribute to maternal immune tolerance to the semiallogeneic fetus. The potential role of decidual stromal granulocytes in regulating the development of early human pregnancy is discussed.