Hydrogen peroxide promotes the activation of preeclampsia peripheral T cells

Preeclampsia (PE) is a pregnancy disorder with a high mortality rate. Patients with PE exhibit systemic high oxidative stress status and inflammatory immune activation. This study aims to define the role of H₂O₂ in the activation of neutrophils and T lymphocytes in PE patients. CD3⁺/HLA-DR⁺ cells in blood from PE patients are remarkably increased compared with those of normal non-pregnancies or normal pregnancies, while the percentage of CD3⁺/CD62L⁺ cells is significantly reduced in PE patients compared to normal pregnancies. Furthermore, CD62L levels in granulocytes of periphery blood of PE patients are significantly higher than non-pregnancies, but significantly lower than normal pregnancies. To characterize the effects of intracellular reactive oxygen species (ROS) on T lymphocyte activation in PE patients, PBMCs from normal pregnancies were challenged with H₂O₂, and intracellular ROS levels in neutrophil granulocytes, as well as T cell surface marker levels, have been determined. We confirm that H₂O₂ exposure increases intracellular ROS levels in neutrophil granulocytes, and increases the proportion of CD3⁺/HLA-DR⁺ cells, but does not alter the percentage of CD3⁺/CD62L⁺ cells in PBMCs. Our study has confirmed dysregulated CD3⁺/HLA-DR⁺ and CD3⁺/CD62L⁺ T lymphocytes in PE patient peripheral blood, and the dysregulative effects of H₂O₂ on T lymphocyte activation, suggesting a novel mechanism of immune activation in PE.