Figure 3.

Neutralisation of cell-cell spread by HIV-1 infected primary CD4+ T cells. Antibodies targeting the CD4 binding site (A), the MPER and gp120 glycans (B), and non neutralising antibody controls (B6 and Lab5), were serially diluted and incubated with HIV-1 (NL4.3) infected primary CD4+ T cells for 1 h at 37°C exactly as in Figure 1. Uninfected target T cells containing a luciferase-reporter gene were added and cells incubated for 24 h as described in the methods to allow for cell-cell spread of HIV-1. Data are shown as the percentage neutralisation normalised to virus-only controls and representative of three independent experiments. (C) The average IC50 values (μg/ml) were generated from duplicate titrations of the indicated antibodies in three independent experiments and show the mean with the SEM.