PT - JOURNAL ARTICLE AU - Liu, Yanling AU - Budylowski, Patrick AU - Dong, Shilan AU - Li, Zhijie AU - Goroshko, Sofiya AU - Leung, Leslie Y. T. AU - Grunebaum, Eyal AU - Campisi, Paolo AU - Propst, Evan J. AU - Wolter, Nikolas E. AU - Rini, James M. AU - Zia, Amin AU - Ostrowski, Mario AU - Ehrhardt, Götz R. A. TI - SARS-CoV-2–Reactive Mucosal B Cells in the Upper Respiratory Tract of Uninfected Individuals AID - 10.4049/jimmunol.2100606 DP - 2021 Nov 15 TA - The Journal of Immunology PG - 2581--2588 VI - 207 IP - 10 4099 - http://www.jimmunol.org/content/207/10/2581.short 4100 - http://www.jimmunol.org/content/207/10/2581.full SO - J. Immunol.2021 Nov 15; 207 AB - Pre-existing SARS-CoV-2–reactive B cells are found in tonsillar tissue.SARS-CoV-2–reactive Abs can be generated de novo.Pre-existing SARS-CoV-2–reactive Abs have neutralizing potential.SARS-CoV-2 is a respiratory pathogen that can cause severe disease in at-risk populations but results in asymptomatic infections or a mild course of disease in the majority of cases. We report the identification of SARS-CoV-2–reactive B cells in human tonsillar tissue obtained from children who were negative for coronavirus disease 2019 prior to the pandemic and the generation of mAbs recognizing the SARS-CoV-2 Spike protein from these B cells. These Abs showed reduced binding to Spike proteins of SARS-CoV-2 variants and did not recognize Spike proteins of endemic coronaviruses, but subsets reacted with commensal microbiota and exhibited SARS-CoV-2–neutralizing potential. Our study demonstrates pre-existing SARS-CoV-2–reactive Abs in various B cell populations in the upper respiratory tract lymphoid tissue that may lead to the rapid engagement of the pathogen and contribute to prevent manifestations of symptomatic or severe disease.This article is featured in Top Reads, p.