title: Periovulatory increases in tissue homing potential of circulating CD56(bright) cells are associated with fertile menstrual cycles.
abstract: CD56(bright) lymphocytes appear in the uterus 3-5 d after ovulation coincident with the onset of stromal cell decidualization. Although the source of these uterine immune cells is not defined, a subset of blood CD56(bright) cells exhibits enhanced capacity to adhere to decidual vascular endothelium during the periovulatory period of menstrual cycles. In this study, the effects of early pregnancy on the adhesive capacity of CD56(bright) cells to bind uterine substrates were examined in a time-course study of 18 infertile women undergoing natural cycles before transfer of frozen/thawed embryos and 18 infertile women undergoing controlled ovarian stimulation. There were three pregnancies in the natural cycle group and seven in the hormone-stimulated cohort. Hormone levels, and number and quality of transferred embryos were similar between pregnant and nonpregnant cycles. However, the adhesive function of CD56(bright) cells increased before ovulation in hormone-treated women who became pregnant and before embryo transfer in naturally cycling women who became pregnant. This pattern of incremental adhesion, which was less frequently observed in unsuccessful cycles, suggests a role for NK cells in implantation. These results support the idea that temporal control of NK cell homing to the uterine microenvironment is a prerequisite to pregnancy.
authors.affiliation: Department of Pediatrics, Child Health Research Institute, 800 Commissioner's Road East, University of Western Ontario, London, Ontario, Canada N6C 2V5. mvandenh@uwo.ca
authors.forename: Marianne J
authors.initials: MJ
authors.lastname: van den Heuvel
authors.forename: Julie
authors.initials: J
authors.lastname: Horrocks
authors.forename: Siamak
authors.initials: S
authors.lastname: Bashar
authors.forename: Kota
authors.initials: K
authors.lastname: Hatta
authors.forename: Suzanne
authors.initials: S
authors.lastname: Burke
authors.forename: Sharon S
authors.initials: SS
authors.lastname: Evans
authors.forename: B Anne
authors.initials: BA
authors.lastname: Croy
authors.forename: Francis R
authors.initials: FR
authors.lastname: Tekpetey
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000097:blood / Q000235:genetics; D019002:CD56 Antigen / Q000097:blood / Q000235:genetics*; D004624:Embryo Transfer; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000097:blood / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000276:immunology*; D008597:Menstrual Cycle / Q000276:immunology*; D010060:Ovulation / Q000276:immunology*; D011247:Pregnancy; D011256:Pregnancy Outcome
chemical_list: D015703:Antigens, CD; D019002:CD56 Antigen