Martin C. Carr

Ontogeny of cellular immunity in the human fetus: development of responses to phytohemagglutinin and to allogeneic cells.

Abstract Human fetal lymphoid cells from thymus, spleen, blood, liver, and bone marrow of 22 fetuses (5–19 weeks of fetal age) were studied for their ability to respond to phytohemagglutinin and to adult allogeneic lymphocytes by the mixed lymphocyte reaction. The earliest detectable response was that by hepatic cells in the mixed lymphocyte reaction at 7.5 weeks of fetal age. Phytohemagglutinin reactivity was initially seen in the thymus at 10 weeks, in blood at 14.5 weeks, and in spleen at 13 weeks. Mixed lymphocyte reaction reactivity was first detected in the thymus at 12.5 weeks; it appeared somewhat later in peripheral organs. Few significant responses to phytohemagglutinin were detected in bone marrow or hepatic cells, and virtually no response to allogeneic cells was found in bone marrow. All lymphoid cells studied showed stimulatory ability in the mixed lymphocyte reaction. However, spleen, blood, and marrow cells produced higher stimulation of allogeneic cells than did thymic or hepatic cells.

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

Abstract 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.

Ontogeny of immunity in humans.

Abstract During embryogenesis differentiation of cells originally derived from the single-celled zygote results in the emergence of an organism with highly complex humoral and cellular immune systems. In some species, particularly the mouse and the chicken, detailed descriptive and experimental analysis of the elements and interrelationships of the complex process of immunologic differentiation have been possible. Such studies have given rise to the original concept of a two-component immune system, one for humoral and the other for cellular immune reactions, each with its separate central organ, e.g., the bursa of Fabricius and the thymus in the chicken, respectively. The study of the ontogeny of immunity in man is still in its infancy and currently limited largely because of legal and moral restraints. However, through the use of tissue culture and other sensitive in vitro techniques, human immunologic embryology has recently emerged as a provocative and scientifically exciting endeavor. The following summarizes salient aspects of our current knowledge of the development of cellular and humoral immunity in the human fetus.

Effect of serum on human rosette-forming cells in fetuses and adult blood

Abstract The action of fetal calf serum and gamma globulin-free calf serum in the rosette formation between sheep red blood cells and mononuclear cells was studied in the lymphoid tissues of 12 human fetuses and the blood of 50 adults. It was found that serum increases the number of rosette-forming cells (RFC) in the fetal thymus, spleen, and blood, and in the adult blood. In contrast, rosette formation was decreased or abolished in fetal bone marrow. In one fetus studied, the bone marrow RFC showed phagocytic activity while in the other lymphoid tissues the RFC did not possess such activity. RFC from adult blood were not able to ingest carbon particles. Some normal subjects were followed during several months for their blood RFC performed in presence of serum; no important variation was noted. Therefore, the use of serum appears to be a valuable tool for studying thymus-derived cells.

Study into the Mechanisms of Damage of Human Placental Syncytiotrophoblast

The microscopic characteristics of in vitro maternal plasma-induced syncytical trophoblast damage were studied. They were compared to structural alterations and/or damage produced by trypsin, pronase,