title: Membrane progesterone receptors in human regulatory T cells: a reality in pregnancy.
abstract: OBJECTIVE
  To provide evidence of the existence of membrane progesterone receptor alpha (mPRα) on regulatory T cells (Treg) in peripheral blood during pregnancy, postulating a possible explanation for the effect of progesterone on preterm birth.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Tertiary Obstetric Department in a University Hospital.
  
  
  METHODS
  Healthy pregnant women.
  
  
  METHODS
  Treg cells from peripheral blood samples were studied by flow cytometry using multiple monoclonal antibody expression.
  
  
  METHODS
  Evaluate the number and percentage of CD4(+) CD25(high) CD127(low) , the number and percentage of Treg cells among the total CD4(+) T cells, and the percentage and mean fluorescence intensity (MFI) of mPRα in that population, using several gating strategies.
  
  
  RESULTS
  43 peripheral blood samples were collected from healthy women during pregnancy, whose median gestational age was 28.7 ± 7.1 (16-40) weeks. The percentage of CD4(+) in the total lymphocytes was 43% (32-51) and the percentage of CD4(+) CD25(high) CD127(low) was 4.8% (1.6-5.9), with only 45% (16-72) of those cells expressing the intracellular marker FoxP3 (Treg cell pool). We confirmed the existence of mPRα in that specific population because 8.0% (2.02-33) of the Treg cells were marked with the specific monoclonal antibody, with an mPRα(+) MFI of 719 (590-1471).
  
  
  CONCLUSIONS
  This research shows that Treg cells express mPRα during pregnancy, which might play an important role in immune modulation by progesterone.
authors: Faculty of Medicine, University of Coimbra and Obstetric Unit, Coimbra University Hospital Centre, Coimbra, Portugal.
authors: A
authors: A
authors: Areia
authors: Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors: S
authors: S
authors: Vale-Pereira
authors: Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors: V
authors: V
authors: Alves
authors: Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors: P
authors: P
authors: Rodrigues-Santos
authors: Faculty of Medicine, University of Coimbra and Obstetric Unit, Coimbra University Hospital Centre, Coimbra, Portugal.
authors: P
authors: P
authors: Moura
authors: Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors: A
authors: A
authors: Mota-Pinto
mesh_terms: D000328:Adult; D015704:CD4 Antigens / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D053699:Interleukin-7 Receptor alpha Subunit / Q000378:metabolism; D010298:Parity; D011247:Pregnancy / Q000097:blood*; D011264:Pregnancy Trimesters / Q000097:blood; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism*; D055815:Young Adult
chemical_list: D015704:CD4 Antigens; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C508017:IL2RA protein, human; D053645:Interleukin-2 Receptor alpha Subunit; D053699:Interleukin-7 Receptor alpha Subunit; D043562:Receptors, G-Protein-Coupled; D011980:Receptors, Progesterone; C513556:PAQR7 protein, human
keywords: Pregnancy; T regulatory cells; progesterone receptor