Trophoblast cells condition neutrophil activation to maintain immune homeostasis at early pregnancy

CALO G, SABBIONE F, PAPARINI D, RAMHORST R, TREVANI A, PÉREZ LEIRÓS C

Mar del Plata

Simposio; VI Latin American Symposium of Reproductive Immunology and V. Latin American Symposium American Society of Reproductive Immunology; 2015

American Society of Reproductive Immunology

The maintenance of the maternal-placental interface is a dynamic process that involves different populations of leucocytes controlled by trophoblast cells to favor a tolerogenic microenvironment. Neutrophil activation is increased in preeclampsia compared with normal pregnancies. Vasoactive intestinal peptide (VIP) is an immunomodulatory peptide produced by trophoblast cells proposed to contribute to homeostasis maintenance at early pregnancy.ObjectiveTo explore the profile acquired by human neutrophils after interaction with trophoblast cells with special focus on VIP effect.MethodsBlood was obtained from healthy donors, neutrophils purified on Ficoll-Triyosom gradient and Dextran, and cultured with conditioned media (CM) from a first trimester human cytotrophoblast cell line (Swan-71) or VIP. Neutrophils were stimulated with fMLP or PMA; CD11b and ROS production was evaluated by FACS; DNA and elastase activity were quantified by fluorometry and spectrophotometry. Migration through transwells was evaluated by FACS. Spontaneous apoptosis was assessed by fluorescence microscopy and phagocytosis of these apoptotic cells by macrophages was then evaluated by cytometry.ResultsThe interaction of neutrophils with trophoblast cells or VIP modulated their functional profile, particularly activation markers, migration and spontaneous apoptosis. Both CM and VIP diminished CD11b expression and ROS production in fMLP-activated neutrophils (MIF X±SE: fMLP: 1076±163; fMLP+VIP10nM: 644±91; fMLP+CM: 777±107 P