Prolonged gestation does not extend survival of uterine natural killer lymphocytes in mice deleted in the receptor for prostaglandin F2alpha.
During decidualization in mice and women, expansion of the Natural Killer (NK) cell lineage occurs within the uterus. In rodents, peak numbers of uterine (u)NK cells are reached at mid-gestation. The population then declines and residual cells are shed with the placenta. Decidualization, but not a fetus, is required to induce division and maturation of uNK cells. Mechanisms regulating the decline in uNK cells are unknown. To determine if the conceptus or its products have regulatory roles on uNK cell survival during normal gestation, a histological time course study was undertaken of implantation sites in mice ablated in the gene for the Prostaglandin F2alpha receptor (PGF2alphaR). These females experience normal gestation but fail to initiate labour and delivery. Their pregnancies extend a further 4-7 days before onset of maternal compromise. Large numbers of uNK cells were present in PGF2alphaR null mice by gestational day (gd) 10 and numbers had begun to decline at gd 14. By gd 18, very few uNK cells remained and no uNK cells were found at day 22 of extended gestation. Thus, the population history of uNK cells in PGF2alphaR null mice resembles that of uNK cells in normal mice, suggesting that the placenta, its products, the fetus and PGF2alpha are not factors that influence the rate of uNK cell decline in late gestation.
Croy
B A
BA
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Canada. acroy@uoguelph.ca
Chantakru
S
S
Narumiya
S
S
Ichikawa
A
A
Sugimoto
Y
Y
D000818:Animals; D002470:Cell Survival; D015237:Dinoprost / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D007694:Killer Cells, Natural / Q000166:cytology*; D051379:Mice; D018345:Mice, Knockout; D007744:Obstetric Labor Complications / Q000276:immunology* / Q000473:pathology; D011247:Pregnancy; D011982:Receptors, Prostaglandin / Q000172:deficiency* / Q000235:genetics; D014599:Uterus / Q000276:immunology* / Q000473:pathology
D011982:Receptors, Prostaglandin; C034671:prostaglandin F2alpha receptor; D015237:Dinoprost