Pregnancy is a complex physiological process involving several interconnected systems. Many researchers were concerned that the formation of a fetus with different genetic components may contradict the normal state of...Pregnancy is a complex physiological process involving several interconnected systems. Many researchers were concerned that the formation of a fetus with different genetic components may contradict the normal state of immunity, which attempts to reject and fight foreign bodies. This piqued the interest of biologists and immunologists, who set out to discover the immune system’s composition and mode of response in the uterus. According to several studies, natural killer (NK) cells are present in a significant percentage that differs from what is seen in peripheral blood. As a result, several scientific studies have been conducted on uterine NK cells, investigating their types, characteristics, receptors, secretions, and interactions with the surrounding environment. Research has also indicated the capacity of uterine NK cells to strike a balance between eradicating uterine infections and effectively contributing to different phases of pregnancy. Various studies have shown that NK cell activity is intimately related to the success or failure of pregnancy. In this review, we describe the uterine NK cell subtypes;decidual (dNK) cells and endometrial NK cells (eNK) cells and their important role during different phases of pregnancy.展开更多
Decidual natural killer （dNK） cells express an array of activation receptors to regulate placental immunity and development during early pregnancy. We investigated the functional character of human dNK cells during ...Decidual natural killer （dNK） cells express an array of activation receptors to regulate placental immunity and development during early pregnancy. We investigated the functional character of human dNK cells during the first and second trimester of gestation and the interaction between dNK and trophoblast cells. Although the frequency of CD56＋CD16-dNK among the total CD45＋ leukocytes did not change over this period, the expression of the activating receptors, NKp80 and NKG2D, was greatly upregulated. We observed a significantly higher number of extravillous trophoblast cells in proximity to the dNK cells in the first trimester in comparison with the second trimester decidua. NKG2D expression by first trimester dNK cells was decreased when co-cultured with the HTR-8 trophoblast cell line. In the second trimester, functional markers of dNK activation, i.e., angiogenic factor production （e.g., vascular endothelial growth factor, interleukin-8, interferon-gamma）, remained stable despite an increase in NKp80 or NKG2D surface expression. Furthermore, the degranulation capacity of dNK cells, as assessed by CD107a, was decreased in the second trimester. We suggest that in the first trimester, trophoblast-dNK interactions generate a population of dNK cells with a suppressed activating phenotype. In the second trimester, the loss of trophoblast-dNK interactions led to the inhibition of dNK cell function, although their activating receptor expression was increased. We speculate that during pregnancy, two mechanisms operate to modulate the dNK cell activation：suppression of activating receptor levels in the first trimester by trophoblasts and disengagement of receptor-ligand coupling in the second trimester.展开更多
文摘Pregnancy is a complex physiological process involving several interconnected systems. Many researchers were concerned that the formation of a fetus with different genetic components may contradict the normal state of immunity, which attempts to reject and fight foreign bodies. This piqued the interest of biologists and immunologists, who set out to discover the immune system’s composition and mode of response in the uterus. According to several studies, natural killer (NK) cells are present in a significant percentage that differs from what is seen in peripheral blood. As a result, several scientific studies have been conducted on uterine NK cells, investigating their types, characteristics, receptors, secretions, and interactions with the surrounding environment. Research has also indicated the capacity of uterine NK cells to strike a balance between eradicating uterine infections and effectively contributing to different phases of pregnancy. Various studies have shown that NK cell activity is intimately related to the success or failure of pregnancy. In this review, we describe the uterine NK cell subtypes;decidual (dNK) cells and endometrial NK cells (eNK) cells and their important role during different phases of pregnancy.
文摘Decidual natural killer （dNK） cells express an array of activation receptors to regulate placental immunity and development during early pregnancy. We investigated the functional character of human dNK cells during the first and second trimester of gestation and the interaction between dNK and trophoblast cells. Although the frequency of CD56＋CD16-dNK among the total CD45＋ leukocytes did not change over this period, the expression of the activating receptors, NKp80 and NKG2D, was greatly upregulated. We observed a significantly higher number of extravillous trophoblast cells in proximity to the dNK cells in the first trimester in comparison with the second trimester decidua. NKG2D expression by first trimester dNK cells was decreased when co-cultured with the HTR-8 trophoblast cell line. In the second trimester, functional markers of dNK activation, i.e., angiogenic factor production （e.g., vascular endothelial growth factor, interleukin-8, interferon-gamma）, remained stable despite an increase in NKp80 or NKG2D surface expression. Furthermore, the degranulation capacity of dNK cells, as assessed by CD107a, was decreased in the second trimester. We suggest that in the first trimester, trophoblast-dNK interactions generate a population of dNK cells with a suppressed activating phenotype. In the second trimester, the loss of trophoblast-dNK interactions led to the inhibition of dNK cell function, although their activating receptor expression was increased. We speculate that during pregnancy, two mechanisms operate to modulate the dNK cell activation：suppression of activating receptor levels in the first trimester by trophoblasts and disengagement of receptor-ligand coupling in the second trimester.
