Figure 2.

NT-193 enhances CoV2- and CoV1-neutralizing activity by the IgG3 subclass

(A) RBD binding affinity of NT-108 and NT-193 was assessed by SPR using CoV1/CoV2 RBD immobilized on the sensor. The K_D value for Fab and apparent K_D (K_D^app) value for IgG1 and IgG3 are shown. ND, not detected. The representative data from two independent experiments are shown.

(B) ELISA plates were coated with CoV2 RBD at high (2 μg/mL) or low (0.1 μg/mL) concentrations. The amounts of NT-193 bound to RBD in the IgG1 and IgG3 subclass are plotted at optical density (OD).

(C and D) CoV2-neutralizing activities of NT-193 and REGN10933 to Wuhan and D614G strains were determined by pseudovirus (C) and authentic virus (D).

(E) CoV1-neutralizing activities of IgG1 and IgG3 purified by the size exclusion fractionation were determined using authentic virus.

(F) WIV-1-neutralizing activities of the indicated antibodies were determined by pseudovirus.

Values represent mean ± SD (B–F). The representative data from three independent experiments are shown (B–F). See also Figure S2.