Double Lock of a Potent Human Monoclonal Antibody against SARS-CoV-2
This article has been Reviewed by the following groups
Listed in
- Evaluated articles (ScreenIT)
Abstract
Receptor recognition and subsequent membrane fusion are essential for the establishment of successful infection by SARS-CoV-2. Halting these steps can cure COVID-19. Here we have identified and characterized a potent human monoclonal antibody, HB27, that blocks SARS-CoV-2 attachment to its cellular receptor at sub-nM concentrations. Remarkably, HB27 can also prevent SARS-CoV-2 membrane fusion. Consequently, a single dose of HB27 conferred effective protection against SARS-CoV-2 in two established mouse models. Rhesus macaques showed no obvious adverse events when administrated with 10-fold of effective dose of HB27. Cryo-EM studies on complex of SARS-CoV-2 trimeric S with HB27 Fab reveal that three Fab fragments work synergistically to occlude SARS-CoV-2 from binding to ACE2 receptor. Binding of the antibody also restrains any further conformational changes of the RBD, possibly interfering with progression from the prefusion to the postfusion stage. These results suggest that HB27 is a promising candidate for immuno-therapies against COVID-19.
Highlights
SARS-CoV-2 specific antibody, HB27, blocks viral receptor binding and membrane fusion
HB27 confers prophylactic and therapeutic protection against SARS-CoV-2 in mice models
Rhesus macaques showed no adverse side effects when administered with HB27
Cryo-EM studies suggest that HB27 sterically occludes SARS-CoV-2 from its receptor
Article activity feed
-
SciScore for 10.1101/2020.11.24.393629: (What is this?)
Please note, not all rigor criteria are appropriate for all manuscripts.
Table 1: Rigor
NIH rigor criteria are not applicable to paper type.Table 2: Resources
Antibodies Sentences Resources Generation of humanized anti-SARS-CoV-2 antibody HB27: SARS-CoV-2 antibodies were screened from a phage-display scFv library constructed from the spleen mRNA of mice immunized with recombinant SARS-CoV-2 RBD protein. anti-SARS-CoV-2suggested: NoneSARS-CoV-2 RBD was used as the bait to select for specific anti-RBD scFvs by biopanning and the scFvs exhibiting potent binding for SARS-CoV-2 RBD were generated as chimeric antibodies. anti-RBDsuggested: NoneHB27 antibody was incubated for 1h, followed by incubation of RBD-His and anti-His-PE,or APC labelled ACE2-Fc for 20 min. anti-His-PEsuggested: (Miltenyi …SciScore for 10.1101/2020.11.24.393629: (What is this?)
Please note, not all rigor criteria are appropriate for all manuscripts.
Table 1: Rigor
NIH rigor criteria are not applicable to paper type.Table 2: Resources
Antibodies Sentences Resources Generation of humanized anti-SARS-CoV-2 antibody HB27: SARS-CoV-2 antibodies were screened from a phage-display scFv library constructed from the spleen mRNA of mice immunized with recombinant SARS-CoV-2 RBD protein. anti-SARS-CoV-2suggested: NoneSARS-CoV-2 RBD was used as the bait to select for specific anti-RBD scFvs by biopanning and the scFvs exhibiting potent binding for SARS-CoV-2 RBD were generated as chimeric antibodies. anti-RBDsuggested: NoneHB27 antibody was incubated for 1h, followed by incubation of RBD-His and anti-His-PE,or APC labelled ACE2-Fc for 20 min. anti-His-PEsuggested: (Miltenyi Biotec Cat# 130-092-691, RRID:AB_1103227)Then the virus was mixed with 0.3 μM ACE2 and HB27 antibody with the final concentration of 2.5 μM, 0.5 μM, 0.1 μM or 0.02 μM. HB27suggested: NoneFive fields were automatically collected in each well to count the number of fused and unfused cells and the antibody inhibition rate was calculated as following: fusion rate (FR) = (fused cell number) / (fused cell number+ unfused cell number), Inhibition%= (Positive Control (FR) – Sample (FR)) / (Positive Control (FR)) %. FRsuggested: NoneFR ) – Sample ( FR) ) / ( Positive Control ( FRsuggested: NoneExperimental Models: Cell Lines Sentences Resources Polyethylenimine was used to transiently transfect HEK Expi 293F cells (Thermo Fisher) with SARS-CoV RBD, SARS-CoV-2 RBD and SARS-CoV-2 S, respectively. HEK Expi 293Fsuggested: None60 μL of SARS-CoV/SARS-CoV-2 pseudoviruses and 60 μL of serial diluted antibody samples were incubated for 1 h at 37°C, after which the pseudovirus-mAb mixtures were added into the wells containing Vero-E6 cells. Vero-E6suggested: NoneImmunofluorescence: 293T cells were transfected with SARS-CoV-2-S-GFP or ACE2-GFP. 293Tsuggested: NonePlaque reduction neutralization tests (PRNT): The neutralization activity of HB27 against SARS-CoV-2 were examined by standard plaque reduction neutralization tests (PRNT) in Vero cells. Verosuggested: CLS Cat# 605372/p622_VERO, RRID:CVCL_0059)Experimental Models: Organisms/Strains Sentences Resources Briefly, a group of 6 to 8-week-old hACE2 humanized mice or BALB/c mice were intraperitoneally administrated with HB27 (20 mg/kg) before (prophylactic) and/or after (therapeutic) challenge with 5 × 105 PFU of SARS-CoV-2 or 1.6×104 PFU of MASCp6 via intranasal route, respectively. BALB/csuggested: NoneSoftware and Algorithms Sentences Resources Data were analyzed using Flowjo and Graphpad. Flowjosuggested: (FlowJo, RRID:SCR_008520)Graphpadsuggested: (GraphPad, RRID:SCR_000306)Movies (32 frames, each 0.2 s, total dose 60 e−Å−2) were recorded at defocuses of between 1.25 and 2.7 μm using SerialEM, yielding a final pixel size of 1.05 Å. SerialEMsuggested: (SerialEM, RRID:SCR_017293)Model building and refinement: The structures of SARS-CoV-2 S trimer and a human Fab fragment (Protein Data Bank ID: 6VSB and 5N4J, respectively) were manually fitted into the refined map of SARS-CoV-2 S trimer-HB27 complex in Chimera (Pettersen et al., 2004) and then improved by manual real-space refinement in COOT (Brown et al., 2015). COOTsuggested: (Coot, RRID:SCR_014222)The final models were evaluated using Molprobity (Chen et al., 2010). Molprobitysuggested: (MolProbity, RRID:SCR_014226)Briefly, a group of 6 to 8-week-old hACE2 humanized mice or BALB/c mice were intraperitoneally administrated with HB27 (20 mg/kg) before (prophylactic) and/or after (therapeutic) challenge with 5 × 105 PFU of SARS-CoV-2 or 1.6×104 PFU of MASCp6 via intranasal route, respectively. SARS-CoV-2suggested: (Active Motif Cat# 91351, RRID:AB_2847848)Results from OddPub: Thank you for sharing your data.
Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.Results from TrialIdentifier: We found the following clinical trial numbers in your paper:
Identifier Status Title NCT04483375 Completed Safety, Tolerability and Pharmacokinetics of SCTA01, an Anti… Results from Barzooka: We did not find any issues relating to the usage of bar graphs.
Results from JetFighter: Please consider improving the rainbow (“jet”) colormap(s) used on pages 40, 41 and 21. At least one figure is not accessible to readers with colorblindness and/or is not true to the data, i.e. not perceptually uniform.
Results from rtransparent:- Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
- Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
- No protocol registration statement was detected.
-