Phenotypic heterogeneity and recycling capacity of natural killer cells in normal human pregnancy

ORIGINAL ARTICLE: Suppression of Natural Killer Cell Cytotoxicity in Postpartum Women

“…5 The natural killer cell cytotoxicity assay (NKCA) of peripheral blood cells from pregnant women also shows diminished cytotoxicity compared with controls during pregnancy. 6 The expression of a number of class I-specific KIR inhibitory receptors increased in the first weeks of pregnancy through the end of the first trimester in eight women studied through their pregnancies. 7 The potential mechanism for inhibited NK function in pregnancy has been attributed in part to pregnancy hormones estrogen, progesterone, and prolactin.…”

“…All NK cells express IL-2 receptors, which upon activation by IL-2 promotes cytotoxicity of the NK cell. 6 After incubation, the cells were centrifuged, resuspended in media, and counted. Viability was always above 80%.…”

Biology of Natural Killer Cells

“…During pregnancy, an NK cell depression is present from the first trimester to the postpartum period (875,876). The mechanism of this depression is not clear, and both normal and decreased levels in the numbers of NK cells, in the NK cell cytotoxic potential, and in the recycling ability have been reported (877)(878)(879)(880). The depression of NK cell cytotoxic activity in pregnancy correlates inversely with the level of 170-estradiol in the sera of pregnant women.…”

The Decidua in Early Pregnancy

“…Alterations in the phenotype, proportions and function of certain NK cell subsets in the peripheral blood of pregnant women have been reported. (30) NK cell activity has also been reported in decidua from early murine pregnancy.''') It is possible that decidual LGL represent a type of NK cell, possibly a developing cell population.…”