HIV Broadly Neutralizing Antibodies: Taking Good Care Of The 98

Abstract

In this issue of Immunity, Huang et al. (2016) describe an exceptionally broad and potent neutralizing antibody to HIV. This antibody, N6, is capable of neutralizing up to 98% of global isolates with a potent median IC₅₀ of 0.04 μg/mL, making it the current "best-in-class" for bNAbs targeting the CD4 binding site.

Figure 1. Breadth and potency of N6 relative to a number of other prototype bnAbs

Broadly neutralizing antibodies targeting different sites of vulnerability on HIV Env are plotted based on their percent coverage and potency. Coverage is defined as the percent of cross-clade viruses neutralized in a large virus panel and potency is defined as the median IC₅₀ of neutralized viruses in μg/mL. The main bnAb epitopes are indicated by color as shown in the figure key. Note that different panels of viruses have been used for many of the antibodies, so comparisons are approximate. For example, PGDM1400 was reported to have 83% breadth and a median IC₅₀ of 0.003 μg/ml {Sok:2014dl}, but measured on the panel in Huang et al., the breadth was reported to be 78% with a median IC₅₀ of 0.008 μg/ml. See Burton and Hangartner (2016) for further details of this type of plot.