FIG 2.

The Phe 43 cavity modulates recognition of clade B, C, and D HIV-1-infected cells by CD4i antibodies and antibodies within HIV⁺ sera. Shown are data for cell surface staining of primary CD4⁺ T cells that were either mock infected or infected with HIV-1 NL4.3-GFP expressing the primary R5 ADA Env (clade B) or SHIV expressing either CH505 (clade C) or 191859 (clade D) Env with anti-CD4 antibody OKT4 (A to C); the Env-specific antibody 2G12 (D and F) or 10e8 (E), which are not influenced by changes in residue 375; CD4i antibodies 17b (G to I) and A32 (J to L); and antibodies within HIV⁺ sera (M to O). Shown are the MFIs obtained from at least 3 independent experiments. Error bars indicate means ± standard errors of the means. Statistical significance was tested by using paired one-way analysis of variance with a Holm-Sidak posttest (*, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001; ns, nonsignificant).