Mixed lymphocyte culture of human fetal liver cells.
OBJECTIVE
In order to study the immunological function of the human fetus in the first and second trimesters, mixed lymphocyte culture (MLC) of fetal liver and thymic cells was performed. MLC is a functional test to determine human lymphocyte antigen-D incompatibilities.


METHODS
Human fetal liver and thymic tissue was obtained from abortions in gestational weeks 7-17.5. Forty-seven fetuses were studied with one-way MLC. The cells were stimulated by adding irradiated fetal liver cells, adult bone marrow and peripheral blood lymphocytes. The activity was measured as DNA incorporation of radiolabeled thymidine.


RESULTS
The results indicate that the human fetus is competent to react as early as 11-12 weeks of gestation and in some cases even earlier. In very immature fetal livers (< 8 weeks), the MLC seems to be inhibited.


CONCLUSIONS
Our data suggest that the human fetus can react against foreign transplantation antigens earlier than previous papers have claimed. The onset of reactivity seems to differ considerably among fetuses. The present findings may explain some of the limited success of in utero transplantations of hematopoietic stem cells in human fetuses of normal immunological status.
Lindton
B
B
Department of Obstetrics and Gynecology, Karolinska Institute, Huddinge University Hospital, Huddinge, Sweden.
Markling
L
L
Ringdén
O
O
Kjaeldgaard
A
A
Gustafson
O
O
Westgren
M
M
D005333:Fetus / Q000276:immunology*; D005865:Gestational Age; D006801:Humans; D008099:Liver / Q000166:cytology / Q000196:embryology* / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology / Q000276:immunology