Neutralization sensitivities of contemporary subtype B HIV-1 Envs.

The neutralization sensitivity of the contemporary, CCR5-utilizing, subtype B pseudoviruses (PSVs) was determined using 31 neutralizing antibodies (NAbs) or reagents. NAbs are colored by specificity, including: V1V2 loop (orange), V3 loop (blue), CD4 binding site (CD4bs, green), membrane proximal external region (MPER, purple), glycan (CHO, yellow) and bridging region (BR, gray). Geometric mean (GM) (A) IC50 and (B) IC80 scores were calculated for each NAb against all PSVs and compared with the percent of PSVs neutralized by each NAb. The red dotted line at 50 indicates the negative cutoff value for this assay; the gray dotted line at 1 indicates the estimated NAb IC80 value for treatment efficacy, as determined by the AMP studies. Neutralization potency of clinically relevant antibodies and antibody combinations was evaluated against early-stage, subtype B HIV-1 Envs. (C) NAbs were tested individually (shown as circles), or (D) in combination (shown as triangles; open if no bispecific antibody was present and gray if bispecific antibody was present). Combinations of NAbs included three NAbs that targeted different domains, as indicated by the x-axis title and the colored legend.