Molecular probes of spike ectodomain and its subdomains for SARS-CoV-2 variants, Alpha through Omicron
Fig 8
Interrogation of SARS-CoV-2 probes using yeast displaying anti-SARS-CoV-2 spike Fabs and immune libraries.
(A) Binding of yeast expressing SARS-CoV cross-reactive Fabs (S652-112, S652-118, and S652-109), SARS-CoV-2 Fabs (CB6, REGN10933, A23-58.1, LY-555, A19-46.1, and REGN10987) or HIV targeting VRC01 Fab to SARS-CoV-2 WA-1, variant D614G, B.1.1.7, B.1.351, P.1, B.1.429, B.1.526-S477N, B.1.526-E484K, B.1.617.1, B.1.617.2, AY.1, B.1.618, C.37, B.1.621, and B.1.1.529 spike ectodomain S2P-APC (left), NTD-BV711 (middle), and RBD-BV421 (right). Binding to the indicated yeast displayed antibody was measured with flow cytometry. Data are shown as Mean Fluorescence Intensity (MFI) for the same antibody against the parental strain WA-1 probe. The normalized percent change is indicated by a color gradient from red (increased binding, Max 400%) to white (no change, 100%) to blue (complete loss of binding, 0%). Within each class of probe (i.e., S2P, NTD and RBD), yeast expressing Fab but do not bind any probes are shown in light grey and marked as “n.b.”. (B) Percentage of human antibody repertoire binding to NTD and RBD of SARS-CoV-2 variants. Natively paired antibody heavy and light chains were captured from COVID-19 convalescent patient immune repertoires and displayed as Fabs on the surface of yeast. Probe binding to the yeast-displayed Fabs was analyzed against pre-conjugated SARS-CoV-2 biotinylated variant probes and measured with flow cytometry. Numbers represent the percentage of binding to the biotinylated probes after subtracting the background fluorescence.