EXTRACELLULAR ATP DRIVES T CELL IMBALANCE IN PEDIATRIC COVID-19

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

Congreso; Reunión Conjunta de Sociedades de Biociencias SAIC-SAI-AAFE-NanoMedAR; 2021

Background: Tregs perturbations correlate with COVID-19 severity in adults although the mechanisms remains unknown. Extracellular ATP is proinflammatory and is regulated by CD39, mainly expressed on Tregs. There is no data regarding Tregs and Th17 cell balance in children with COVID-19.Aims: To analyze the frequency and phenotype of Tregs; quantify the levels of cytokines and ATP in serum and released by stimulated cells; study the effect of extracellular ATP on T cell to stablish an association with the severity of disease. Methods: We used sera, PBMCs or purified T cells from COVID-19 (n=54) and healthy children (n=23) to evaluate the frequency and phenotype of Tregs, Th17 and proliferative response by flow cytometry; the levels of ATP by luminometry; the cytokine secretion by multiplex assays.Results: Children with COVID-19 have a lower frequency of Tregs and a strong suppressive phenotype with higher expression of CD25, CTLA-4 and CD39 (p