Effects of purinergic signaling in neutrophils functions during pediatric COVID-19

ALGIERI, SILVIA; BRUERA, MARÍA JOSÉ; RUSSO, CONSTANZA; GEFFNER, JORGE; SEERY, VANESA; DE CARLI, NORBERTO; DAVENPORT, CAROLINA; BAYLE, CAROLA; ARRUVITO, LOURDES; RAIDEN, SILVINA; SARLI, MARIAM; SANANEZ, INÉS; FERRERO, FERNANDO

Simposio; Maternal-Fetal Newborn Immunity Keystone eSymposium; 2021

Introduction: Evidence implicates neutrophils in the pathophysiology of severe COVID-19. Activated and injured cells release their stores of ATP to the extracellular space, with ATP being generally excitatory to most cells trough purinergic receptors. Here we analyzed plasma levels of ATP in children with COVID-19 and the ability of extracellular purines to modulate the functions of neutrophils from children with COVID-19.Methods: Sixty acute COVID-19 infected children (1-16 years-old) and 20 healthy children (HC) were studied. Levels of ATP were measured in plasma by Luminometry. Purified neutrophils were exposed to ATP and/or an adenosine agonist. Phenotype, levels of myeloperoxidase (MPO), metalloproteinase-9 (MMP-9), osteopontin (OPN), calprotectin (MRP8/14), neutrophil gelatinase associated lipocalin (NGAL) and reactive oxygen species (ROS) production were analyzed by flow cytometry. Neutrophil extracellular traps (NETs) release was measured by Fluorometry. Levels of IL-8 were quantified by ELISA.Results: We found higher levels of ATP in plasma from COVID-19 patients, mainly in those with pneumonia compared with HC