The Expression Of Fas On T Lymphocytes In Peripheral Blood And Nature Killer Cells In Decidual Of Preeclampsia

ObsjectivesProgrammed cell death has been proposed as a mechanism for maintaining the homeostasis in the immune system. It: provides an efficient mechanism for e-liminating activated lymphocytes in the immune system. It is thought that activated lymphocytes are removed by a Fas/FasL - mediated programmed cell death process which is called activiation induced cell death.Fas antigen ( Apo - 1, CD95 molecule) belong to the turner necrosis factor -receptor superfamiliy of type I transmembrane molecules. Surface CD95 antigen has an intracytoplasmic domain responsible for the transmission of apoptotic signals to the cytoplasm of the cell. CD95 molecule is absent on non - activated lymphocytes, but appears on the surface of activated lymphocytes. In this way they become able to undergo Fas/FasL - mediated apoptosis process.Preeclampsia is a common obstetric syndrome , It has been proposed that the activiation of cell - mediated immunity may play a role in the etiology of preeclampsia.The aim of the study was to investigate surface Fas antigen ( Apo - 1, CD95) expression on T lymphocytes and NK cells in preeclampsia patients and healthy pregnant women.Materials and methods Materials1. patients: The patients participating in the study were admitted to the De-partament of Obstetrics and Perinatology of the No. 2 affiliated hospital of China Medical University between May 2003 and October 2004. Thirty patients with preeclampsia at 33 - 37 weeks of gestation comprised the study group. Fifteen healthy women with uncomplicated pregnancy at 36 —39 weeks were the control group. Informed consent from the patients for peripheral blood sampling was obtained.2. Agent and equipment;anti - CD95 - FITC monoclonal antibodies; anti -CD56 - PE monoclonal antibodies; anti - CD3 - PE monoclonal antibodies; FCMMethodsBlood samples from both study group and control group were taken at the moment of admission of the hospital before any treatment. Ten milliliters of blood were taken by venipuncture from each patient and each woman from the control group. Peripheral blood mononuclear cells were separated on lymphocyte separation medium. The cells were labled by direct staining with anti - CD95 monoclonal antibodies. And also lymphocytes were isolated from decidual tissues mechanically, labeled by direct staining with monoclonal antibodies. The cell and antibody mixture was incubated for 20 min at 4℃ in the dark, centrifuged, washed twice. The cell phenotype characterization was performed using the two -colour flow cytometric method. Statisiscal differences between the studied groups were estimated using a standard T - test. The results were presented as the mean with S. D. Differences at P <0. 05 were considered as statistically significant.Results;The expression and concentration of Fas on T lymphocyte was higher in severe - preeclampsia group compared with normal group and mild - preeclampsia group. However the expression and concentration of Fas on nature killer cells was lower in severe - preeclampsia group cornpaxed with normal group.