MAJOR HISTOCOMPATIBILITY COMPLEX AND NON-MAJOR HISTOCOMPATIBILITY COMPLEX ANTIGENS ON MOUSE ECTOPLACENTAL CONE AND PLACENTAL TROPHOBLASTIC CELLS1

Abstract

SUMMARY The expression of major histocompatibility complex and non-major histocompatibility complex antigens on mouse trophoblast cultured from two defined stages of development was investigated by the sensitive in vitro mixed haemadsorption assay. Outgrowths obtained 3 to 5 days after explanation of 7¹/₂-day ectoplacental cones contained a mixed population of cells. Those with a giant cell morphology showed no haemadsorption with congenic H-2 antisera and were reactive with non-H-2 antiserum only in the CBA strain. Other, smaller cells were reactive for both H-2 and non-H-2 in all strains examined except for C57BL, where the cells were nonreactive for H-2. Monolayer cultures of 13 to 14-day placental suspensions tested 24 hr after preparation were strongly reactive for both H-2 and non-H-2. The identity and alloantigenic status of the cells are discussed in relation to their function in maternal-foetal immunological interactions.