Features of transferrin receptor and activation marker expressions by cytotoxic T lymphocyte during physiological pregnancy

This is the authors' abstract. We don't add key points for this paper.

Cells of the immune system accept iron ions from the plasma bound to the transport protein transferrin, which interacts with a specific receptor (CD71) on the cell surface. The density of transferrin receptors on T lymphocytes is directly related to the activation status of the cell and its ability to proliferate and differentiate. During physiological pregnancy, the functional activity of peripheral blood cytotoxic T lymphocytes changes significantly, the cytotoxic potential decreases, the differentiation of naive and memory cells changes, and the spectrum of cytokines produced changes, which contributes to the acquisition of regulatory activity and is necessary for maintaining immune tolerance to the semi-allogeneic fetus. The aim of this investigation is to study the features of the expression of transferrin receptors (CD71) in relation to the activation markers (CD95, HLA-DR) of cytotoxic CD8+ T lymphocytes of peripheral blood of women in the I and III trimesters of physiological pregnancy. The object of the study was the peripheral blood of conditionally healthy non-pregnant women (phase I of the menstrual cycle) and women with a physiologically протекающей pregnancy in the I and III trimesters. Mononuclear cells of the peripheral blood were isolated by sedimentation in a density gradient of ficoll-urographin (1.077 g/cm3) using a standard method. The phenotype of the cells was analyzed using flow cytometry. The expression of CD71 (type 1 transferrin receptor), CD95 (activation marker), and HLA-DR (class II MHC molecule, activation marker) was evaluated in the total population of CD3+ T lymphocytes, as well as on CD3+CD8+ and CD3+CD4+ cells. Physiological pregnancy is accompanied by a decrease in the percentage of CD3+CD8+ T lymphocytes in the peripheral blood in the first trimester compared to non-pregnant women. CD71 expression is found on both CD3+CD4+ and CD3+CD8+ T lymphocytes. CD71 expression increases in the third trimester on cytotoxic CD3+CD8+ T lymphocytes compared to non-pregnant women. In the CD3+CD8+ T lymphocyte population, the percentage of lymphocytes co-expressing CD71 and CD95, as well as CD71 and HLA-DR, decreases in the third trimester of pregnancy compared to non-pregnant individuals. In the overall CD3+CD71+ T lymphocyte population, there is also a decrease in the percentage of both CD95-expressing cells and HLA-DR-positive cells in the third trimester of pregnancy compared to non-pregnant individuals. A decrease in the percentage of cytotoxic CD8+T lymphocytes in peripheral blood during physiological pregnancy is accompanied by an increase in the expression of the transferrin receptor on these cells, which is associated with a change in their activation status.