AUTHOR=Smit Wouter L. , van Tol Sophie , Wal Sanne van der , van Vulpen Femke , la Grouw Shannon , van Lelyveld Lenneke , Limonard Gijs , Bossink Ailko , Godeke Gert-Jan , Shrestha Sandhya , Reimerink Johan , Eggink Dirk , Reusken Chantal , Heron Michiel , Thijsen Steven TITLE=Heterologous Immune Responses of Serum IgG and Secretory IgA Against the Spike Protein of Endemic Coronaviruses During Severe COVID-19 JOURNAL=Frontiers in Immunology VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.839367 DOI=10.3389/fimmu.2022.839367 ISSN=1664-3224 ABSTRACT=

Defining immune correlates of disease severity is important to better understand the immunopathogenesis in COVID-19. Here we made use of a protein microarray platform to detect IgG- and IgA-reactive antibodies in sera and saliva respectively, and assess cross-reactivity between SARS-CoV-2 and endemic coronaviruses (eCoVs). IgG responses against the full protein of spike, but not the S1 subunit, were significantly higher in convalescent sera of patients with severe disease compared to mild disease and healthy controls. In addition, we detected reactivity of secretory IgA to eCoVs in saliva of patients with severe disease, not present in patients with moderate disease or seropositive healthy controls. These heterologous immune responses are in line with non-protective cross-reactivity, and support a potential role for immune imprinting in the pathogenesis of severe COVID-19.