Figure 3

Nef and Vpu reduce susceptibility of infected CD4+ T cells to A32-mediated ADCC. CEM.NKR cells were infected with CCR5-tropic NL4.3.ADA. IRES.GFP viruses as mentioned in Figure 1 legend. Target cells were incubated with control IgG, A32 or 2G12 and analyzed for susceptibility to ADCC mediated by PBMC effector cells. Net Ab-specific cell lysis was computed as described in Figure 2 legend. As a qualitative control for infection, prior to the ADCC evaluation, target cells were also stained for Env expression using anti-Env Abs. (A) Env staining of target cells using A32. (B) An example of net Ab-specific cell lysis (using A32 as test Ab) from a representative donor (donor 143 in Panel C). (C) Comparative analysis of susceptibility of different target cells to A32-mediated ADCC. The five sets of numbers indicated on the right hand side of the lines represent five donors. (D) Summary of net A32-mediated cell lysis from six infections using PBMC from twelve donors as effector cells (each dot represents an individual). (E and F) Susceptibility of ∆Nef∆Vpu virus-infected cells to ADCC induced by A32 compared to that by 2G12. Shown in (E) is the result of a representative donor and in (F) is a summary of three experiments with seven donors, with each line representing data from a given individual. Statistical analysis of data was done using paired Student’s t-tests.