Cellular immune aspects of the human fetal-maternal relationship: III. Mixed lymphocyte reactivity between related maternal and cord blood lymphocytes

Gravida and related cord blood lymphocytes were studied in one-way mixed lymphocyte culture to find out if tolerance or sensitization existed between these organisms. Maternal lymphocytes were consistently stimulated by both related cord blood and adult allogeneic lymphocytes, and the kinetics of the reactions did not suggest that any specific tolerance or sensitization existed toward fetal histocompatibility antigens. Cord blood lymphocytes were stimulated by related maternal lymphocytes in approximately one-half the tests, and also seemed less reactive toward adult allogeneic cells. However, the temporal kinetics of the reaction did not suggest any sensitization or tolerance toward maternal lymphocytes. The findings suggest that the success of the human pregnancy in terms of cell-mediated immunity does not depend upon intrinsic cellular maternal-fetal tolerance.