Immunomodulatory effects of neutrophil extracellular traps (NETs).

SABB; KEITELMAN I; IULA L; PODAZA E; TOWSTYKA N; GIORDANO, M; JANCIC C; TREVANI, AS

Mar del Plata

Congreso; LXII Reunión anual de la SAI,; 2014

Sociedad Argentina de Inmunología y Soc. Argentina de Investigación Clínica

Airway epithelial cells provide a mechanical barrier to prevent lung infection and produce chemokines and cytokines that recruit and activate phagocytic cells. In response to alveolar inflammatory stimuli, neutrophils transmigrate the epithelium to eliminate microorganisms by either phagocytosis or NETs. They are chromatin fibers decorated with antimicrobial proteins that can trap and kill microorganisms. The aim of this study was to address if NETs also exert immunomodulatory actions. NETs were obtained from culture supernatants of neutrophils isolated from healthy donors by stimulation with monosodium urate crystals (300 µg/ml) for 4 h at 37° C, gentle sonication and centrifugation. As controls, neutrophils were also stimulated in the presence of Diphenyleneiodonium (DPI) or elastase inhibitor (EI) to avoid NETs release. The presence of NETs in supernatants was determined by fluorometry. NETs preparations or their controls were added to A549 and BEAS-2B epithelial cells cultures for 24 h at 37 ° C and then supernatants were collected and IL-6 and IL-8 were determined by ELISA. Cell viability was assessed by Annexin V-FITC/PI staining by FACs. NETs increased the secretion of IL-8 and IL-6 by both types of epithelial cells (n=3, p