Specificity of gp120/CD4 blocking antibodies.

<p>A) The IgG response against Env was evaluated by flow cytometry using MOLT-BaL and uninfected-MOLT cell line. The levels of anti-Env IgG antibodies were calculated as MFI ratio (MOLT-BaL/MOLT). B) Titer of antibodies against the soluble trimer BG505 SOSIP.664 gp140 was determined by ELISA. A correlation analysis between the anti-Env levels and gp120/CD4 blocking activity is shown (Spearman´s correlation). C) A set of anti-Env antibodies, whose reactivity is well-known, was used to evaluate the specificity of the antibodies that were able to block the binding of the huCD4mIgG recombinant protein to MOLT-BaL cells. The antibodies tested included CD4bs Abs (VRC01, VRC03), anti-glycosylated epitopes (2G12, PGT126), anti-glycosylated-quaternary epitopes (PG9, PG16), CD4 induced epitopes (17b,48d), anti-gp41 (2F5, 4E10) and a polyclonal goat anti-gp120 (anti-gp120) obtained by immunization using rgp120.