Derivation of functional early gestation decidual natural killer cell subtypes from induced pluripotent stem cells

Abnormal decidual natural killer cell (dNK) function is linked to pregnancy complications occurring in both early and late stages of gestation, including recurrent pregnancy loss, preeclampsia, and preterm birth. Exploration of dNK heterogeneity as it relates to function is an active area of research; however, most of this work has focused on early gestation. We applied flow cytometric and transcriptomic single cell definitions of dNK subtypes to dNK at the chorioamniotic membranes (CAM) and basal plate (BP) of the placenta at term. We found decreased low-effector-function dNK1 and increased high-effector-function dNK3 abundance at term. In comparison to BP-dNK, CAM-dNK had greater abundance of moderate-effector-function dNK2 and lower expression of inhibitory CD9. We applied this knowledge to establish a protocol for differentiation of induced pluripotent stem cells (iPSC) into CD45+CD56brightCD16-, functional dNK-like, applying TGF{beta} to enrich for dNK2 - the most abundant dNK subtype at first trimester- while inducing expression of dNK markers, CD9 and CD103. We analyzed the secretomes of first trimester dNK, term BP-dNK and CAM-dNK, and peripheral blood NK cells to identify proteomic profiles for each. Finally, we analyzed the secretome of TGF{beta}-treated iPSC-dNK and found an enrichment in first trimester dNK-specific proteins. We identify changes in dNK function across gestation and placental region and suggests that these changes can be explained by shifts in dNK subtypes, which we specifically and reproducibly derive from iPSC, providing a new model for these cells and laying the foundation for cell-based therapies of reproductive diseases. Significance StatementAlterations in maternal decidual natural killer cells (dNK) are associated with pregnancy complications - from recurrent pregnancy loss to preeclampsia and preterm birth. We found dNK from different regions of the term placenta to be distinct from peripheral blood NK and early gestation dNK, based on gene and surface marker expression, subtype composition, and secretome. We report a novel, reproducible protocol to generate dNK resembling the most abundant dNK subtype in early gestation from induced pluripotent stem cells. Our study lays the foundation for in vitro modeling of the maternal-fetal interface and therapeutic development for reproductive disease. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/685424v1_ufig1.gif" ALT="Figure 1"> View larger version (56K): org.highwire.dtl.DTLVardef@9b182dorg.highwire.dtl.DTLVardef@507037org.highwire.dtl.DTLVardef@f73238org.highwire.dtl.DTLVardef@1021ce0_HPS_FORMAT_FIGEXP M_FIG C_FIG