title: Natural killer-cell deficiency alters placental development in rats.
abstract: Natural killer (NK) cells are the most prevalent leukocyte population in the uterus during early pregnancy. Natural killer cells contribute to uterine vascular (spiral artery) remodeling in preparation for the increased demand on these vessels later in pregnancy. A second wave of spiral artery modification is directed by invasive trophoblast cells. The significance of the initial wave of NK-cell-mediated vascular remodeling in species exhibiting deep trophoblast invasion such as humans and rats is not known. The purpose of this study was to generate a genetic model of NK-cell deficiency in rats, and determine the consequences of NK-cell deficiency on spiral artery remodeling and reproductive outcomes. To accomplish this task, we utilized zinc finger nuclease-mediated genome editing of the rat interleukin-15 (Il15) gene. Il15 encodes a cytokine required for NK-cell lineage development. Using this strategy, a founder rat was generated containing a frameshift deletion in Il15. Uteri of females harboring a homozygous mutation at the Il15 locus contained no detectable NK cells. NK-cell deficiency did not impact fetal growth or viability. However, NK-cell deficiency caused major structural changes to the placenta, including expansion of the junctional zone and robust, early-onset activation of invasive trophoblast-guided spiral artery remodeling. In summary, we successfully generated an NK-cell-deficient rat and showed, using this model, that NK cells dampen the extent of trophoblast invasion and delay trophoblast-directed spiral artery remodeling. This study furthers our understanding of the role of NK cells on uterine vascular remodeling, trophoblast invasion, and placental development.
authors.affiliation: Institute for Reproductive Health and Regenerative Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.|Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Renaud
authors.affiliation: Institute for Reproductive Health and Regenerative Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.|Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.
authors.forename: Regan L
authors.initials: RL
authors.lastname: Scott
authors.affiliation: Institute for Reproductive Health and Regenerative Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.|Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.
authors.forename: Damayanti
authors.initials: D
authors.lastname: Chakraborty
authors.affiliation: Institute for Reproductive Health and Regenerative Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.|Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.
authors.forename: Mohammad A K
authors.initials: MA
authors.lastname: Rumi
authors.affiliation: Institute for Reproductive Health and Regenerative Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.|Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, USA.|Department of Obstetrics and Gynecology, University of Kansas Medical Center, Kansas City, Kansas, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Soares
mesh_terms: D000818:Animals; D001835:Body Weight; D005260:Female; D019409:Interleukin-15 / Q000172:deficiency / Q000235:genetics; D007694:Killer Cells, Natural / Q000502:physiology*; D008297:Male; D016297:Mutagenesis, Site-Directed; D009929:Organ Size; D010929:Placentation; D011247:Pregnancy; D011256:Pregnancy Outcome; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000473:pathology
chemical_list: D019409:Interleukin-15
keywords: interleukin 15; invasion; natural killer cells; placenta; pregnancy; spiral artery; trophoblast; vascular remodeling