Expansion of SARS-CoV-2-specific Antibody-secreting Cells and Generation of Neutralizing Antibodies in Hospitalized COVID-19 Patients

Varnaite, R.; Garcia, M.; Glans, H.; Maleki, K. T.; Sandberg, J. T.; Tynell, J.; Christ, W.; Lagerqvist, N.; Asgeirsson, H.; Ljunggren, H.-G.; Ahlen, G.; Frelin, L.; Sällberg, M.; Blom, K.; Klingström, J.; Gredmark-Russ, S.

doi:10.1101/2020.05.28.118729

bioRxiv · 10.1101/2020.05.28.118729

Expansion of SARS-CoV-2-specific Antibody-secreting Cells and Generation of Neutralizing Antibodies in Hospitalized COVID-19 Patients

Varnaite, R.·Garcia, M.·Glans, H.·Maleki, K. T.·Sandberg, J. T.·Tynell, J.·Christ, W.·Lagerqvist, N.·Asgeirsson, H.·Ljunggren, H.-G.·Ahlen, G.·Frelin, L.·Sällberg, M.·Blom, K.·Klingström, J.·Gredmark-Russ, S.

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Abstract

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019 and has since become a global pandemic. Pathogen-specific antibodies are typically a major predictor of protective immunity, yet B cell and antibody responses during COVID-19 are not fully understood. Here, we analyzed antibody-secreting cell (ASC) and antibody responses in twenty hospitalized COVID-19 patients. The patients exhibited typical symptoms of COVID-19, and presented with reduced lymphocyte numbers and increased T cell and B cell activation. Importantly, we detected an expansion of SARS-CoV-2 nucleocapsid protein-specific ASCs in all twenty COVID-19 patients using a multicolor FluoroSpot assay. Out of the 20 patients, 16 had developed SARS-CoV-2-neutralizing antibodies by the time of inclusion in the study. SARS-CoV-2-specific IgA, IgG and IgM antibody levels positively correlated with SARS-CoV-2-neutralizing antibody titers, suggesting that SARS-CoV-2-specific antibody levels may reflect the titers of neutralizing antibodies in COVID-19 patients during the acute phase of infection. Lastly, we showed that interleukin 6 (IL-6) and C-reactive protein (CRP) concentrations were higher in serum of patients who were hospitalized for longer, supporting the recent observations that IL-6 and CRP could be used to predict COVID-19 severity. Altogether, this study constitutes a detailed description of clinical and immunological parameters in twenty COVID-19 patients, with a focus on B cell and antibody responses, and provides tools to study immune responses to SARS-CoV-2 infection and vaccination.

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Varnaite, R., Garcia, M., Glans, H., Maleki, K. T., Sandberg, J. T., Tynell, J., Christ, W., Lagerqvist, N., Asgeirsson, H., Ljunggren, H.-G., Ahlen, G., Frelin, L., Sällberg, M., Blom, K., Klingström, J., Gredmark-Russ, S.. 2020-05-29. Expansion of SARS-CoV-2-specific Antibody-secreting Cells and Generation of Neutralizing Antibodies in Hospitalized COVID-19 Patients. https://doi.org/10.1101/2020.05.28.118729

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