Human Decidual Natural Killer Cells Express the Receptor for and Respond to the Cytokine Interleukin 15

• Published in: Biology of reproduction 2000-04, Vol.62 (4), p.959-968
• Main Authors: Verma, S, Hiby, S E, Loke, Y W, King, A
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Cell Division - drug effects; Cell Line; Cell Survival - drug effects; Decidua - cytology; Decidua - drug effects; Decidua - metabolism; Female; Flow Cytometry; Fundamental and applied biological sciences. Psychology; Humans; Interleukin-12 - biosynthesis; Interleukin-12 - pharmacology; Interleukin-15 - metabolism; Interleukin-15 - pharmacology; Interleukin-18 - pharmacology; Killer Cells, Natural - drug effects; Killer Cells, Natural - metabolism; Mammalian female genital system; Morphology. Physiology; Phenotype; Placenta - drug effects; Placenta - metabolism; Pregnancy; Receptors, Interleukin-15; Receptors, Interleukin-2 - biosynthesis; Receptors, Interleukin-2 - drug effects; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - biosynthesis; Stem Cell Factor - pharmacology; Trophoblasts - drug effects; Vertebrates: reproduction
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod62.4.959

The natural killer (NK) cells that are present in the uterine mucosa (decidua) during early pregnancy have a distinctive phenotype, CD56 bright CD16 − . These cells have previously been shown to proliferate and be activated by interleukin (IL)-2. However, IL-2 is absent from the decidua and placenta, and we have therefore investigated whether IL-15 is present in the uterus and can act on decidual NK cells. Both IL-15 mRNA and protein were found in a variety of cells but particularly in decidual macrophages. IL-15 induced a proliferative response in decidual NK cells that was blocked by anti-IL-15 and was augmented by stem cell factor. The cytolytic activity of decidual NK cells against K562 was augmented. Interestingly, in contrast to IL-2, although activation with IL-15 resulted in some killing of JEG-3 choriocarcinoma cells, normal trophoblast cells remained resistant to lysis. These findings suggest that IL-15 is a candidate cytokine responsible for NK cell proliferation in vivo in the progesterone-dominated secretory endometrium and early decidua.