FIG 7.

Histidine 375 modulates ADCC responses against CRF01_AE HIV-1-infected cells mediated by antibodies isolated from RV144 vaccinees. Primary CD4⁺ T cells infected with the WT or the H375S variant of CRF01_AE transmitted-founder HIV-1 (IMC 703357) were used as target cells, with autologous PBMCs as effector cells, in our FACS-based ADCC assay. Shown are the percentages of ADCC activity in the presence of the A32-blockable monoclonal antibodies (CH29, CH38, CH40, CH51, CH52, CH54, CH77, CH80, CH81, CH89, CH91, and CH94) isolated from RV144 vaccinees. These results are representative of those obtained in at least 5 independent experiments. Error bars indicate means ± standard errors of the means. Statistical significance was tested by using an unpaired two-tailed t test (*, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001).