FIG 2 .

Neutralizing capacity of CD4 binding site (CD4bs) antibodies. (A) The ability of CD4bs monoclonal antibodies (listed on the right) to neutralize HIV-1, SIVcpz, and SIVgor strains (listed on the bottom) is shown. Numbers indicate IC₅₀s (in micrograms per milliliter) in TZM-bl cells, averaged from three different experiments, with a heat map indicating the relative neutralization potency. The highest antibody concentration was 10 µg/ml. A herpesvirus antibody (anti-HSV-gD) was used as a negative control. (B) Conservation of HIV-1, SIVcpz, and SIVgor strains in the CD4 binding region. An alignment of Env protein sequences (left) in regions surrounding the CD4 binding site is shown. CD4 and VRC01 contact resides (indicated in the HXB2 reference strain) are highlighted in orange and green, respectively. A logo plot above the alignment denotes the conservation of each amino acid, with the height of each letter indicating the proportion of the sequences that contain the residue at that site. Dots indicate identity to the HXB2 reference sequence, and dashes represent gaps introduced to improve the alignment.