High levels of HIV integration with minimal virus production in CCL19-treated infected CD4+ T-cells consistent with latent infection. (A). Schematic diagram of the experimental protocol used for isolation of CD4+ T-cells and HIV infection. Resting CD4+ T-cells were cultured for 2 days with PHA/IL-2, CCL19 or without activation (unactivated). Cells were then infected with WT NL4.3, NL4.3Δenv or NL4.3-Δnef/EGFP or mock for 2 hrs and virus was washed off. The infected cells were cultured with media containing IL-2 (10 IU/mL) for 4 days. Infection of cells with WT NL4.3 (open bars) or NL4.3Δenv (grey bars) was quantified by detection of (B) integrated HIV DNA (C) RT activity (CPM/μl) in culture supernatant or (D) luciferase activity of supernatants using the TZM-bl indicator cell line. In all graphs, the mean (column) and individual data (open symbols) from two donors are shown.