No substantial pre-existing B cell immunity against SARS-CoV-2 in healthy adults

Ercanoglu, M. S.; Gieselmann, L.; Daehling, S.; Poopalasingam, N.; Detmer, S.; Koch, M.; Korenkov, M.; Halwe, S.; Kluever, M.; Di Cristanziano, V.; Janicki, U. H.; Schlotz, M.; Worczinski, J.; Gathof, B.; Gruell, H.; Zehner, M.; Becker, S.; Vanshylla, K.; Kreer, C.; Klein, F.

doi:10.1101/2021.09.08.459398

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bioRxiv · 10.1101/2021.09.08.459398

No substantial pre-existing B cell immunity against SARS-CoV-2 in healthy adults

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Abstract

Pre-existing immunity against SARS-CoV-2 may have critical implications for our understanding of COVID-19 susceptibility and severity. Various studies recently provided evidence of pre-existing T cell immunity against SARS-CoV-2 in unexposed individuals. In contrast, the presence and clinical relevance of a pre-existing B cell immunity remains to be fully elucidated. Here, we provide a detailed analysis of the B cell response to SARS-CoV-2 in unexposed individuals. To this end, we extensively investigated the memory B cell response to SARS-CoV-2 in 150 adults sampled pre-pandemically. Comprehensive screening of donor plasma and purified IgG samples for binding and neutralization in various functional assays revealed no substantial activity against SARS-CoV-2 but broad reactivity to endemic betacoronaviruses. Moreover, we analyzed antibody sequences of 8,174 putatively SARS-CoV-2-reactive B cells on a single cell level and generated and tested 158 monoclonal antibodies. None of the isolated antibodies displayed relevant binding or neutralizing activity against SARS-CoV-2. Taken together, our results show no evidence of relevant pre-existing antibody and B cell immunity against SARS-CoV-2 in unexposed adults.

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Ercanoglu, M. S., Gieselmann, L., Daehling, S., Poopalasingam, N., Detmer, S., Koch, M., Korenkov, M., Halwe, S., Kluever, M., Di Cristanziano, V., Janicki, U. H., Schlotz, M., Worczinski, J., Gathof, B., Gruell, H., Zehner, M., Becker, S., Vanshylla, K., Kreer, C., Klein, F.. 2021-09-08. No substantial pre-existing B cell immunity against SARS-CoV-2 in healthy adults. https://doi.org/10.1101/2021.09.08.459398

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