title: The frequency of peripheral blood CD4+ CD25high FoxP3+ and CD4+ CD25- FoxP3+ regulatory T cells in normal pregnancy and pre-eclampsia.
abstract: OBJECTIVE
  Regulatory T cells (Tregs) play an important role in the development of pregnancy-specific immune tolerance. We aimed to determine the peripheral frequency of a recently described Treg subpopulation, the CD4+ CD25- FoxP3+ Treg subset, and its correlation with the conventional CD4+ CD25high FoxP3+ Tregs in normal pregnancy (NP) and pre-eclampsia (PE) compared to non-pregnant (non-P) women. We also examined the proportion of the activated CD4+ CD25high FoxP3high Treg subset within conventional Treg cells.
  
  
  METHODS
  We took peripheral blood samples from 20 PE, 20 NP, and 12 non-P women and determined the frequency of the above Treg subsets using flow cytometry.
  
  
  RESULTS
  The frequency of conventional CD4+ CD25high FoxP3+ Tregs and activated CD4+ CD25high FoxP3high Tregs, but also that of non-conventional CD4+ CD25- FoxP3+ Tregs was higher in NP compared to non-P women, but lower again in PE, reaching comparable levels to the non-P group. The ratios of CD4+ CD25high FoxP3+ and CD4+ CD25- FoxP3+ Treg subsets were constant in all three investigated groups.
  
  
  CONCLUSIONS
  Our results indicate that the frequency of conventional and non-conventional Tregs alters simultaneously, and the presence in circulation of both of these Treg subsets is similarly important in the adequate development of pregnancy-specific immune tolerance.
authors.affiliation: First Department of Pediatrics, Semmelweis University, Budapest, Hungary.
authors.forename: Gergely
authors.initials: G
authors.lastname: Toldi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Saito
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shima
authors.forename: Amrita
authors.initials: A
authors.lastname: Halmos
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Veresh
authors.forename: Barna
authors.initials: B
authors.lastname: Vásárhelyi
authors.forename: János
authors.initials: J
authors.lastname: Rigó
authors.forename: Attila
authors.initials: A
authors.lastname: Molvarec
mesh_terms: D000328:Adult; D015704:CD4 Antigens / Q000378:metabolism; D002478:Cells, Cultured; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D011225:Pre-Eclampsia / Q000276:immunology* / Q000473:pathology; D011247:Pregnancy; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D015704:CD4 Antigens; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit