title: Maturation of human ovarian follicles is accompanied by a decrease in the CD56+CD16+ natural killer cell population.
abstract: OBJECTIVE
  To investigate whether "proangiogenic" CD56+CD16- natural killer (NK) cells, which accumulate in follicular fluid (FF) of patients with a good response to ovarian stimulation, are also present in earlier stages of follicular development.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Academic in vitro fertilization (IVF) unit.
  
  
  METHODS
  Patients of similar age and ovarian reserve, undergoing in vitro maturation (IVM; n=10) or IVF (n=22) cycles.
  
  
  METHODS
  None.
  
  
  METHODS
  FF was collected from the first follicle aspirated in each ovary, and flow cytometry was used to define CD56+CD16- "proangiogenic" or CD56+CD16+ "cytotoxic" NK cells.
  
  
  RESULTS
  FF derived from antral follicles of patients undergoing IVM (maximum diameter 10 mm) showed a slightly higher abundance of "proangiogenic" NK cells compared with FF from preovulatory mature follicles (>18 mm) of patients undergoing IVF (5.4±1.3% vs. 3.0±1.1% of CD45+CD3- cells). Importantly, antral FF contained a significantly higher concentration of "cytotoxic" NK cells (11.4±2.3% vs. 3.7±0.9% of CD45+CD3- cells) compared with FF from mature follicles.
  
  
  CONCLUSIONS
  "Proangiogenic" NK cells accumulate in ovarian follicles from as early as the antral follicular stage. Maturation of follicles is accompanied by a decrease in the population of "cytotoxic" NK cells that may have deleterious effects on follicular maturation.
authors: IVF Unit, Department of Obstetrics and Gynecology, Hillel Yaffe Medical Center, Hadera, Israel. ofainaru@techunix.technion.ac.il
authors: Ofer
authors: O
authors: Fainaru
authors: Shay
authors: S
authors: Hantisteanu
authors: Nechami
authors: N
authors: Rotfarb
authors: Medeia
authors: M
authors: Michaeli
authors: Mordechai
authors: M
authors: Hallak
authors: Adrian
authors: A
authors: Ellenbogen
mesh_terms: D000328:Adult; D019002:CD56 Antigen / Q000032:analysis*; D015536:Down-Regulation; D005260:Female; D005307:Fertilization in Vitro; D005434:Flow Cytometry; D015571:Follicular Fluid / Q000276:immunology*; D005498:Follicular Phase; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D018919:Neovascularization, Physiologic; D054315:Oocyte Retrieval; D006080:Ovarian Follicle / Q000098:blood supply / Q000276:immunology*; D010062:Ovulation Induction; D017452:Receptors, IgG / Q000032:analysis*
chemical_list: D019002:CD56 Antigen; C522918:NCAM1 protein, human; D017452:Receptors, IgG