AUTHOR=Kilpeläinen Athina , Jimenez-Moyano Esther , Blanch-Lombarte Oscar , Ouchi Dan , Peña Ruth , Quirant-Sanchez Bibiana , Perez-Caballero Raul , Chamorro Anna , Blanco Ignacio , Martínez-Caceres Eva , Paredes Roger , Mateu Lourdes , Carrillo Jorge , Blanco Julià , Brander Christian , Massanella Marta , Clotet Bonaventura , Prado Julia G. TITLE=Skewed Cellular Distribution and Low Activation of Functional T-Cell Responses in SARS-CoV-2 Non-Seroconvertors JOURNAL=Frontiers in Immunology VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.815041 DOI=10.3389/fimmu.2022.815041 ISSN=1664-3224 ABSTRACT=

The role of T cells in the control of SARS-CoV-2 infection has been underestimated in favor of neutralizing antibodies. However, cellular immunity is essential for long-term viral control and protection from disease severity. To understand T-cell immunity in the absence of antibody generation we focused on a group of SARS-CoV-2 Non-Seroconvertors (NSC) recovered from infection. We performed an immune comparative analysis of SARS-CoV-2 infected individuals stratified by the absence or presence of seroconversion and disease severity. We report high levels of total naïve and low effector CD8+ T cells in NSC. Moreover, reduced levels of T-cell activation monitored by PD-1 and activation-induced markers were observed in the context of functional SARS-CoV-2 T-cell responses. Longitudinal data indicate the stability of the NSC phenotype over three months of follow-up after infection. Together, these data characterized distinctive immunological traits in NSC including skewed cellular distribution, low activation and functional SARS-CoV-2 T-cell responses. This data highlights the value of T-cell immune monitoring in populations with low seroconversion rates in response to SARS-CoV-2 infection and vaccination.