Figure 4.
Germline-revertant antibody reactivity and functional activity
Group 1, 2, or 3 germline-revertant antibodies are shown in purple, pink, or yellow, respectively. DENV 2D22 was used as a control antibody for all assays, as shown in the lines in black. All experiments were performed in biological replicate and technical triplicate. Biological replicate from representative single experiment is shown, mean ± SD of triplicates is shown.
(A) Binding to SARS-CoV-2 S6Pecto, SARS-CoV-2 RBD, or SARS-CoV-1 S2Pecto was measured by absorbance at 450 nm, as shown in the first three columns.
(B) Binding to Vero cells infected with VSV-SARS-CoV-2, measured by flow cytometric analysis and reported as median florescence intensity.
(C) Results for neutralization curves for replication-competent VSV chimeric viruses in real-time cell analysis (RTCA) are shown in the next three columns, measured by percent neutralization calculated by normalized cell index.
(D) Binding EC50 and neutralization IC50 values for each of the assay curves in Figure 5A. All values are denoted as μg/mL. ACE2 blocking was determined by measuring the amount of ACE2 with FLAG tag binding in the presence of each antibody, measured by binding of an anti-FLAG antibody. Percent blocking is shown, calculated by using ACE2 binding without antibody as 0% blocking.
(E) Inhibition binding curves for the group 3 germline-revertant antibody. The starting antibody concentration used was 10 μg/mL and was titrated 3-fold serially to obtain ACE2-blocking curves.