Effect of cytotrophoblast cells on T lymphocyte surface antigen expression in cultures of peripheral blood mononuclear cells from pregnant woman and umbilical cord blood mononuclear cells from newborns.

We studied the action of cytotrophoblast cells (CTC) on the expression of T lymphocyte membrane markers in the cultures of newborn cord blood mononuclear cells (CBMC) and peripheral blood mononuclear cells (PBMC) of a pregnant woman. The CTC were separated from the placental chorion at ten weeks of gestation time. In this abstract we show that the CTC and the CTC culture supernatant (SN) increase the number of HLA DR(+)CD7(+) T cells activated by anti-CD3 mAbs, both in PBMC and CBMC cultures. CTC increased the number of transferrine receptor CD71(+) lymphocytes without anti-CD3 activation in CBMC cultures. The increase in the blood mononuclear cell proliferation did not come with an increase of HLA DR and CD71 expression induced by CTC or SN. Moreover, SN caused the suppression of activated T lymphocyte proliferation. We found no signs of any influence of CTC and SN on the expression of CD25 in CD4(+) and CD8(+) subpopulations of T lymphocytes, either activated or non-activated by anti-CD3. The data regarding the CTC- and SN-induced HLA DR expression in vitro suggest that the previously determined high level of HLA DR(+) T cells in the placenta and decidua in pregnant women might have been the result the activity of the trophoblast cells and their soluble products on the lymphocytes of that area.