Sorting of VRC 018 B cells from donor N751 identifies antibodies 2C06 and 2C09 that neutralize BG505
Langmuir
(A) VRC 018 clinical regimen and a flowchart for B cell sorting and antibody screening.(B) Single B cell sorting with glycan-base BG505 trimer probes reveals only a small fraction of memory B cells from VRC 018 clinical trial to be directed to the glycan-dense surface of the Env trimer versus its glycan-free base.(C) AlphaLISA screening of RATP-Ig supernatants from sorted B cells for antibodies that bind both BG505 DS-SOSIP and glycan-base BG505. Data were measured in triplicates; error bars represent standard error of the mean (SEM).(D) Apparent affinity measurement of top antibodies from AlphaLISA screening for binding to BG505 DS-SOSIP and glycan-base BG505 trimers. Antibody IgGs were expressed and purified, and their binding to trimers was measured by Carterra. 2G12 and VRC01 were used as positive controls. Motavizumab was used as negative control, and no binding was observed.(E) Antibodies 2C06 and 2C09 neutralize BG505, but no other tested strains. Asterisk denotes tier status for BI369.9A unknown but resistant to antibodies 17b, 48d, F105, 3074, and 447-52D that neutralize only laboratory-adapted strains.(F) Affinity of antibody Fabs binding to BG505 DS-SOSIP trimer, measured by SPR.Data in (D) and (F) were measured once and the curves fitted with a simple 1:1 Langmuir binding model for the reported mean ± SEM. See also 