AUTHOR=Nückel Julius , Planatscher Elisa , Mohr Anne Wiebe , Deichl Karolin , Mijočević Hrvoje , Feuerherd Martin , Wolff Lisa , Erber Johanna , Schneider Jochen , Quante Michael , Winter Christoph , Ruland Jürgen , Hapfelmeier Alexander , Hammerschmidt Wolfgang , Moosmann Andreas , Protzer Ulrike , Behrends Uta , Mautner Josef TITLE=Association between IgG responses against the nucleocapsid proteins of alphacoronaviruses and COVID-19 severity JOURNAL=Frontiers in Immunology VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.889836 DOI=10.3389/fimmu.2022.889836 ISSN=1664-3224 ABSTRACT=

Understanding immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial to contain the COVID-19 pandemic. Using a multiplex approach, serum IgG responses against the whole SARS-CoV-2 proteome and the nucleocapsid proteins of endemic human coronaviruses (HCoVs) were measured in SARS-CoV-2-infected donors and healthy controls. COVID-19 severity strongly correlated with IgG responses against the nucleocapsid (N) of SARS-CoV-2 and possibly with the number of viral antigens targeted. Furthermore, a strong correlation between COVID-19 severity and serum responses against N of endemic alpha- but not betacoronaviruses was detected. This correlation was neither caused by cross-reactivity of antibodies, nor by a general boosting effect of SARS-CoV-2 infection on pre-existing humoral immunity. These findings raise the prospect of a potential disease progression marker for COVID-19 severity that allows for early stratification of infected individuals.