SUPPRESSION OF INVITRO LYMPHOCYTE STIMULATION IN MICE BY UTERINE AND PLACENTAL EXTRACTS

  • 1 January 1976
    • journal article
    • research article
    • Vol. 117  (5) , 1644-1650
Abstract
The effects of uterine extracts from virgin mice and uterine and placental extracts from mice at various stages of gestation on lymphocyte stimulation in vitro were compared. Placental and uterine extracts from mice in gestation, at 1% final concentration by volume, caused marked depression of lymphocyte reactivity to phytohemagglutinin-P (PHA) and to allogeneic cells in 2-way mixed leukocyte cultures (MLC). An equivalent concentration of uterine extract from virgin mice caused slight depression of lymphocyte reactivity. Suppression was most marked with uterine extracts of mice at 15 days of gestation. At least 2 factors of different molecular weight in uterine and placental extracts were responsible for suppression of lymphocyte reactivity. The higher molecular weight fraction, present in small amounts in the uteri of virgin mice, was markedly increased in uteri of pregnant mice. This fraction contained immunoglobulin G (IgG). These factors may be involved in a protective role for the fetus from rejection by the mother as an allograft, assuring successful pregnancy.