RT Journal Article SR Electronic T1 Murine monoclonal antibodies against RBD of SARS-CoV-2 neutralize authentic wild type SARS-CoV-2 as well as B.1.1.7 and B.1.351 viruses and protect in vivo in a mouse model in a neutralization dependent manner JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.04.05.438547 DO 10.1101/2021.04.05.438547 A1 Fatima Amanat A1 Shirin Strohmeier A1 Wen-Hsin Lee A1 Sandhya Bangaru A1 Andrew B. Ward A1 Lynda Coughlan A1 Florian Krammer YR 2021 UL http://biorxiv.org/content/early/2021/04/06/2021.04.05.438547.abstract AB After first emerging in December 2019 in China, severe acute respiratory syndrome 2 (SARS-CoV-2) has since caused a pandemic leading to millions of infections and deaths worldwide. Vaccines have been developed and authorized but supply of these vaccines is currently limited. With new variants of the virus now emerging and spreading globally, it is essential to develop therapeutics that are broadly protective and bind conserved epitopes in the receptor binding domain (RBD) or the whole spike of SARS-CoV-2. In this study, we have generated mouse monoclonal antibodies (mAbs) against different epitopes on the RBD and assessed binding and neutralization against authentic SARS-CoV-2. We have demonstrated that antibodies with neutralizing activity, but not non-neutralizing antibodies, lower viral titers in the lungs when administered in a prophylactic setting in vivo in a mouse challenge model. In addition, most of the mAbs cross-neutralize the B.1.351 as well as the B.1.1.7 variants in vitro.Importance Crossneutralization of SARS-CoV-2 variants by RBD-targeting antibodies is still not well understood and very little is known about the potential protective effect of non-neutralizing antibodies in vivo. Using a panel of mouse monoclonal antibodies, we investigate both of these aspects.