FIG 1.
Antibody recognition of cleaved and uncleaved HIV-1 Envs on the cell surface. (A) HOS cells transiently expressing the wild-type HIV-1JR-FL Env, a fraction of which is cleaved in these cells, were incubated with the indicated broadly neutralizing antibodies or poorly neutralizing antibodies. After washing and lysis of the cells, the antibody-Env complexes were purified with protein A-Sepharose beads and analyzed by Western blotting with a goat anti-gp120 polyclonal serum. (B) The effect of cross-linking with BS3 and/or BMS-806 treatment on antibody binding to HIV-1JR-FL Env(−) on the surface of CHO cells was evaluated by cell-based ELISA. BMS-806 (10 μM) was added to the CHO cells at the time of induction of Env(−) expression with doxycycline. All values were normalized against 2G12 antibody binding and were derived from at least three independent experiments. Note that the HIV-1JR-FL Env(−) glycoprotein is not recognized by the PGT145 V2 quaternary antibody, which serves as a negative control.