title: Maternal and fetal factors that contribute to the localization of T regulatory cells during pregnancy.
abstract: OBJECTIVE
  To determine the interplay between fetal antigenicity and local maternal factors in determining reproductive tract T regulatory (Treg) cell accumulation during pregnancy.
  
  
  METHODS
  Examination of maternal Treg composition in the uterus, cervix, and uteroplacental interface (UPI) of murine syngeneic and allogeneic pregnancies and non-pregnant controls by flow cytometry. The impact of fetal antigenicity was defined by either fetal gender in syngeneic pregnancies or by allogeneic paternity. Impact of IL-6 on local Treg composition was determined using syngeneic pregnancies in IL-6(-/-) females.
  
  
  RESULTS
  An increased fraction of CD4(+) T cells in the pregnant uterine lymphocytic infiltrate and draining pelvic lymph nodes are Tregs. Maternal IL-6 decreases Treg accumulation within the uterus and to a greater extent in the cervix in syngeneic pregnancy. Fetal antigenicity is matched by accumulation of Tregs to the UPI. Treg accumulation at the UPI of non-antigenic female fetuses is determined by the intrauterine position relative to male siblings.
  
  
  CONCLUSIONS
  Reproductive tract tissue Treg composition during pregnancy is influenced by maternal IL-6 and fetal antigenicity.
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of OB/GYN, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Carrie M
authors.initials: CM
authors.lastname: Wambach
authors.forename: Sonal N
authors.initials: SN
authors.lastname: Patel
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Kahn
mesh_terms: D000818:Animals; D002465:Cell Movement; D002584:Cervix Uteri / Q000166:cytology / Q000276:immunology*; D005260:Female; D005333:Fetus / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D015850:Interleukin-6 / Q000276:immunology; D008297:Male; D008431:Maternal-Fetal Exchange / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology*; D014599:Uterus / Q000166:cytology / Q000276:immunology*
chemical_list: D015850:Interleukin-6
keywords: Allogeneic; T regulatory; cervix; interleukin-6; uteroplacental interface