Phenotypic and functional characterization of peripheral T cell populations from COVID-19 patients hospitalized in Hospital Privado Universitario Córdoba- Argentina.

ONOFRIO L*, DUTTO J*, BOSSIO CV LAURA CHIAPELLO 7 S*, BAIGORRI E*, BRUGO MB*, ALMADA L**, MARÍN C**, RUIZ MORENO F**, VOLPINI X**, ALMEIDA M, OLIVERA C,; PONCE N, QUIROZ JM, SILVERA RUIZ S, BOFELLI L, ACOSTA RODRÍGUEZ E, AMEZCUA VESELY C, ARROYO D; CERBÁN F, CERVI L, FOZZATTI L, ICELY P, IRIBARREN P, MALETTO B, MORÓN G, RODRÍGUEZ GALÁN C, STEMPIN C; BERTONE M#, ABIEGA A#, ESCUDERO D#, KAHN A#, CAEIRO JP#,; MACCIONI M, MOTRÁN M,; CHIAPELLO L, MONTES C, GRUPPI A, SOTOMAYOR C.; GRUPO IMMUNOCOVIDCBA

Buenos Aires

Congreso; Reunión Conjunta SAIC. SAI. AAFE.NANOMED.AR.; 2021

Sociedad Argentina de Inmunología

In severe disease, pulmonary inflammation is associated with increased plasma levels of proinflammatory cytokines, a phenomenon called ?cytokine storm?. T cells could contribute to the infection outcome, but it remains unclear whether T cell response is dysfunctional or excessive.Heparinized peripheral blood samples were collected from healthy volunteers (HC) and Covid-19 patients from Hospital Privado de Córdoba during the first wave of infection (Oct-Dec 2020). Peripheral blood mononuclear cells (PBMCs) were isolated using Ficoll-Hypaque (GE Healthcare) and stored at -80 0C. The samples were thawed, and flow cytometric (FACS) analysis was performed. For phenotypic analysis, PBMCs were incubated with fluorochrome-labelled primary antibodies. For functional analysis and intracellular cytokine determination cells were stimulated with PMA/ ionomycin in the presence of brefeldin and monensin. All samples were acquired in BD LRS Fortessa Flow Cytometer and analyzed using FlowJo softwareThe disease severity impacts on the phenotype and functional features of CD4+ and CD8+ T cells, with a pronounced increment in the % of CD8lo T cells as the disease worsens. These cells appear to have dysfunctional phenotype with an impairment of effector cytokines production but maintaining cytotoxic potential. The CD8hi/CD8lo ratio might be a useful parameter to predict the disease outcome