title: Progesterone-modulated phosphatidylserine externalization in apoptosis and activation of Jurkat cells.
abstract: OBJECTIVE
  During pregnancy the elevated levels of progesterone (Pg) have immunomodulating effects. It is important to follow-up Pg effects on basic biological processes at cell level as apoptosis and activation which was the aim of this study.
  
  
  METHODS
  Jurkat cells cultured in the presence or absence of Pg were used as a model system. Apoptosis was induced by H(2)O(2) and activation by phorbol myriastate acetate. The induced changes in the phosphatidylserine (PS) externalization and cell surface CD69 expression were followed by fluorescence-activated cell sorter and immunofluorescence.
  
  
  RESULTS
  After the induction of apoptosis PS externalizes in 52.3% of Jurkat cells. Cells cultured with Pg show tendency to a decrease of PS positive cells (42%). The opposite effect is observed in activated cells--PS externalization increase from 33.8% of control cells to 40.1% of Pg-treated cells.
  
  
  CONCLUSIONS
  These findings would suggest that by increasing activation and decreasing apoptosis Pg could regulate local immune system during pregnancy.
authors.affiliation: Department of Molecular Immunology, Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 73 Tzarigradsko shosse, 1113 Sofia, Bulgaria. milena_mourdjeva@hotmail.com
authors.forename: Milena
authors.initials: M
authors.lastname: Mourdjeva
authors.forename: Zlatka
authors.initials: Z
authors.lastname: Popova
authors.forename: Dobroslav
authors.initials: D
authors.lastname: Kyurkchiev
authors.forename: Katerina
authors.initials: K
authors.lastname: Kontinopoulou
authors.forename: Iskra
authors.initials: I
authors.lastname: Altankova
authors.forename: Ivan
authors.initials: I
authors.lastname: Kehayov
authors.forename: Stanimir
authors.initials: S
authors.lastname: Kyurkchiev
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D001693:Biological Transport, Active / Q000502:physiology; D006801:Humans; D019169:Jurkat Cells; D008213:Lymphocyte Activation / Q000276:immunology / Q000502:physiology*; D010718:Phosphatidylserines / Q000378:metabolism*; D011374:Progesterone / Q000502:physiology*
chemical_list: D010718:Phosphatidylserines; D011374:Progesterone