• Immunoregulation;
  • mature dendritic cells;
  • pregnancy;
  • sex steroid hormones

Problem:  Dendritic cells (DCs) play an important role in antigen presentation and immunoregulation. Modifications of the immune response during pregnancy require the participation of DC. The aim of this study was to follow-up the changes of DCs in human decidua and their correlations to progesterone (Pg) concentrations.

Methods of study:  Blood leukocytes were isolated from human decidua and analyzed by flow cytometry for the expression of HLA-DR and CD83 markers. Blood monocytes were cultured to differentiate and mature to DCs in the presence of Pg, estradiol or testosterone and analyzed by flow cytometry.

Results:  The percentage of mature DCs is increased in human decidua during the 1st trimester. When Pg is added to DCs cultured in vitro the percentage of cells expressing both markers increased in specific and dose-dependent manner.

Conclusions:  Pg increases the numbers of monocytic DCs locally and it may be speculated that these cells help the Th1/Th2 switching in pregnancy.