Human Decidual Natural Killer Cells Are a Unique NK Cell Subset with Immunomodulatory Potential

TLDR

NK cells comprise 50–90% of lymphocytes in early pregnancy decidua. The study compared CD56bright decidual NK cells to peripheral NK subsets using microarray, flow cytometry, and RT‑PCR. dNK cells show distinct transcriptional profiles, with 278 genes up‑regulated relative to peripheral NK cells, including surface proteins such as NKG2E, Ly‑49L, KIRs, integrins, tetraspanins, and secreted immunomodulators galectin‑1 and progestagen‑associated protein 14.

Abstract

Natural killer cells constitute 50–90% of lymphocytes in human uterine decidua in early pregnancy. Here, CD56bright uterine decidual NK (dNK) cells were compared with the CD56bright and CD56dim peripheral NK cell subsets by microarray analysis, with verification of results by flow cytometry and RT-PCR. Among the ∼10,000 genes studied, 278 genes showed at least a threefold change with P ≤ 0.001 when comparing the dNK and peripheral NK cell subsets, most displaying increased expression in dNK cells. The largest number of these encoded surface proteins, including the unusual lectinlike receptors NKG2E and Ly-49L, several killer cell Ig-like receptors, the integrin subunits αD, αX, β1, and β5, and multiple tetraspanins (CD9, CD151, CD53, CD63, and TSPAN-5). Additionally, two secreted proteins, galectin-1 and progestagen-associated protein 14, known to have immunomodulatory functions, were selectively expressed in dNK cells.