EXPRESSION OF MOLECULES CHARACTERIZING METABOLIC AND CYTOTOXIC ACTIVITY OF DIFFERENT NATURAL KILLER CELL SUBPOPULATIONS IN PERIPHERAL BLOOD DURING PREGNANCY
The functions of peripheral blood natural killer (NK) cells change significantly throughout pregnancy, which is mainly due to the inhibition of their cytotoxicity. Although the functional activity of NK cells is directly related to their metabolic status, these changes during physiological pregnancy have not been studied. The aim of this work was to study the expression of Glut-1, CD94, and CD107a molecules characterizing metabolic and cytotoxic activity, as well as the mitochondrial mass, in different peripheral blood NK cell subpopulations of healthy women during first and third trimesters of physiological pregnancy. The control group comprised healthy non-pregnant women in the follicular phase of the menstrual cycle. The expression of Glut-1, CD94, CD107a molecules and the mitochondrial mass were analyzed by flow cytometry in regulatory (CD16–CD56bright), cytotoxic (CD16+CD56dim), and minor cytotoxic (CD16hiCD56–) NK cells. It was found that in non-pregnant women, minor cytotoxic CD16hiCD56– NK cells had the highest expression of Glut-1 and CD107a and the lowest expression of CD94 compared to other NK cell subpopulations. In regulatory CD16–CD56bright and cytotoxic CD16+CD56dim NK cells, the expression of these molecules was similar, as was the mitochondrial mass in all subpopulations studied. In the first trimester, Glut-1 expression increased on regulatory CD16–CD56bright NK cells, while mitochondrial mass and the expression of CD94 and CD107a on all NK cells did not differ from those in non-pregnant women. In the third trimester, mitochondrial mass increased, but CD94 expression decreased, in cytotoxic CD16+CD56dim NK cells compared to non-pregnant women, while CD94 expression on regulatory CD16–CD56bright NK cells was higher than in the first trimester. CD107a expression on minor cytotoxic CD16hiCD56– NK cells decreased, while remaining unchanged in other subpopulations compared to non-pregnant women. Glut-1 expression did not change in all subpopulations. Thus, different subpopulations of peripheral blood NK cells are heterogeneous in the expression of Glut-1, CD107a, and CD94. The expression of these molecules during physiological pregnancy varies by trimesters. The obtained results are important for understanding the regulatory mechanisms of NK cell functioning during pregnancy.
