SARS-CoV-2 neutralizing antibody structures inform therapeutic strategies
Christopher O. Barnes, Claudia A. Jette, Morgan E. Abernathy, Kim-Marie A. Dam, Shannon R. Esswein, Harry B. Gristick, Andrey G. Malyutin, Naima G. Sharaf, Kathryn E. Huey-Tubman, Yu E. Lee, Davide F. Robbiani, Michel C. Nussenzweig, Anthony P. West Jr & Pamela J. Bjorkman
The coronavirus disease 2019 (COVID-19) pandemic presents an urgent health crisis. Human neutralizing antibodies that target the host ACE2 receptor-binding domain (RBD) of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spike protein1,2,3,4,5 show promise therapeutically and are being evaluated clinically6,7,8. To identify the structural correlates of SARS-CoV-2 neutralization, we solved eight new structures of distinct COVID-19 human neutralizing antibodies5 in complex with the SARS-CoV-2 spike trimer or RBD. Structural comparisons allowed us to classify the antibodies into categories: (1) Neutralizing antibodies encoded by the VH3-53 gene segment with short CDRH3 loops that block ACE2 and bind only to ‘up’ RBDs; (2) ACE2-blocking neutralizing antibodies that bind both up and ‘down’ RBDs and can contact adjacent RBDs; (3) neutralizing antibodies that bind outside the ACE2 site and recognize both up and down RBDs; and (4) previously described antibodies that do not block ACE2 and bind only up RBDs9. Class 2 contained four neutralizing antibodies with epitopes that bridged RBDs, including a VH3-53 antibody that used a long CDRH3 with a hydrophobic tip to bridge between adjacent down RBDs, thereby locking the spike into a closed conformation. Epitope and paratope mapping revealed few interactions with host-derived N-glycans and minor contributions of antibody somatic hypermutations to epitope contacts.
Characterization of neutralizing antibody with prophylactic and therapeutic efficacy against SARS-CoV-2 in rhesus monkeys
Shuang Wang, Yun Peng, […]Datao Liu
Nature Communications volume 11, Article number: 5752 (2020)
Efficacious interventions are urgently needed for the treatment of COVID-19. Here, we report a monoclonal antibody (mAb), MW05, with SARS-CoV-2 neutralizing activity by disrupting the interaction of receptor binding domain (RBD) with angiotensin-converting enzyme 2 (ACE2) receptor. Crosslinking of Fc with FcγRIIB mediates antibody-dependent enhancement (ADE) activity by MW05. This activity is eliminated by introducing the LALA mutation to the Fc region (MW05/LALA). Potent prophylactic and therapeutic effects against SARS-CoV-2 are observed in rhesus monkeys. A single dose of MW05/LALA blocks infection of SARS-CoV-2 in prophylactic treatment and clears SARS-CoV-2 in three days in a therapeutic treatment setting. These results pave the way for the development of MW05/LALA as an antiviral strategy for COVID-19.
Quantification of SARS-CoV-2 neutralizing antibody by a pseudotyped virus-based assay
Jianhui Nie, Qianqian Li, Jiajing Wu, Chenyan Zhao, Huan Hao, Huan Liu, Li Zhang, Lingling Nie, Haiyang Qin, Meng Wang, Qiong Lu, Xiaoyu Li, Qiyu Sun, Junkai Liu, Changfa Fan, Weijin Huang, Miao Xu & Youchun Wang
Nature Protocols (2020)
Pseudotyped viruses are useful virological tools because of their safety and versatility. On the basis of a vesicular stomatitis virus (VSV) pseudotyped virus production system, we developed a pseudotyped virus-based neutralization assay against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in biosafety level 2 facilities. Compared with the binding antibody test, the neutralization assay could discriminate the protective agents from the antibody family. This protocol includes production and titration of the SARS-CoV-2 S pseudotyped virus and the neutralization assay based on it. Various types of samples targeting virus attachment and entry could be evaluated for their potency, including serum samples derived from animals and humans, monoclonal antibodies and fusion inhibitors (peptides or small molecules). If the pseudotyped virus stock has been prepared in advance, it will take 2 days to get the potency data for the candidate samples. Experience in handling cells is needed before implementing this protocol.