ATP AFFECTS FOLLICULAR T HELPER CELLS DURING PEDIATRIC RSV INFECTION

RUSSO C; RAIDEN S; ALGIERI, S; BRUERA, MJ; DE CARLI N; SARLI, M; CAIROLI H; DE LILLO L; MORALES I; SEERY V; OTERO, ADRIÁN; SANANEZ I; SIMAZ N; ALFIERO G; RUBINO G; MOYA N; AEDO PORTELA L; PEREYRA M; FERRERO FERNANDO; GEFFNER J; ARRUVITO LOURDES

Congreso; Reunión Anual de SAI 2023; 2023

Background: Respiratory syncytial virus (RSV) infection represents a major burden in infants. Follicular T helper cells (Tfh) play a critical role in the generation of protective antibodies. The purinergic receptor P2X7R has been recognized as a signature gene of Tfh cells. The expression and function of P2X7R on Tfh cells from RSV-infected infants have not been analyzed previously.Aims: 1) To characterize circulating Tfh cells (cTfh) in RSV-children 2) To quantify IL-21 levels in serum, ATP and P2X7R cleaved soluble form (P2X7Rs) levels in serum and nasopharyngeal aspirates (NPA) 3) To analyze the membrane P2X7R expression in cTfh 4) To explore the biologic response of cTfh to ATP (P2X7R agonist) and KN-62 (P2X7R antagonist) 5) To study the correlation with the Clinical Disease Severity Score (CDSS).Methods: Plasma, NPA and PBMCs from children with non-severe (n=46) and severe RSV infection (n=26) and controls (n=23) were used. Results: We observed decreased cTfh frequency in non-severe (n=30) and severe RSV-infected infants (n=15) compared with controls (n=23,p