Fig. 4.

Co-receptor binding site antibodies facilitate anti-cluster A antibody recognition of HIV-1-infected cells in the presence of CD4mc.

(a–c) Cell-surface staining of primary CD4 + T cells either mock-infected or infected with NL4.3 GFP expressing the primary R5 ADA Env with AF647-conjugated (a–b) A32 or (c) C11, in the presence or not of co-receptor binding site (CoRBS) mAbs 17b, C2, N12-i2, 48d or 412d, CD4 binding site (CD4BS) mAbs VRC01 or b12, anti-V3 mAbs 19b, anti-V2 mAbs CH58 or human IgG, with CD4mc JP-III-48 or DMSO. Shown in (a) are histograms depicting representative A32-AF647 staining and (b–c) the mean fluorescence intensities (MFI) obtained for at least 7 different staining. (d) Cell-surface staining of primary CD4 + T cells either mock-infected or infected with CH58 T/F with AF647-conjugated A32 in the presence or not of the Fab fragment, the Fab′2 fragment or the full 17b with CD4mc JP-III-48 or DMSO. Shown in (d) are (left) histograms depicting representative staining and (right) the MFI for at least 9 different staining. Error bars indicate mean ± SEM. Statistical significance was tested using a Kruskal-Wallis with a Dunn's post-test (*p < 0.05, **p < 0.01, ****p < 0.0001, ns: non-significant). See also Fig. S2, S3 and S4.