Suppression of Maternal Lymphocyte Mitogenic Responses by Supernatants From Short‐Term Placental Cell Cultures

Abstract

Human placental cells were freed from lymphocyte contamination on discontinuous BSA gradients. Supernatants from short-term cultures of these purified placental cell suspensions were predominantly suppressive for maternal lymphocyte blast transformation to phytohemagglutinin and in the mixed lymphocyte culture. The suppressor factor was nondialyzable and did not contain IgG or human chorionic gonadotropin.