Fig. 3.

C1 region gp120-specific IgG mAbs block binding of CH38 IgA₂ mAbs. HIV-1 Env (AE.A244Δ11 gp120) was incubated with the IgG mAbs representing C1 conformation mAbs from four different RV144 vaccinees. These antigen–antibody complexes were then flowed over the monoclonal antibody coupled to the sensor surface: CH38 mAb IgA₂. CH38 IgA₂ mAb was blocked for binding to gp120 Env by IgG antibodies with specificities for the C1 region of gp120. The percent blocking of mAb binding was calculated relative to the mAb binding in the presence of a control gp41 antibody (7B2). Means and SDs of percentage blocking are from four measurements.