No productive HIV infection in CCL19-treated infected cells. Resting CD4+ T cells were cultured for 2 days with PHA/IL-2, CCL19 or without activation (unactivated). Cells were infected with NL4.3 or NL4.3-Δnef/EGFP for 2 hrs. The virus was washed off and the infected cells were cultured with media containing IL-2 (10 IU/mL) for up to 4 days. Productive infection was detected by flow cytometry of (A) intracellular HIV p24 (Alexa-488) following infection with NL4.3 (left panels; two representative donors). The right hand panels show the corresponding integrated copies of HIV per million cells for the same donors (as the mean of two donors (column) and as individual data (open symbols)). (B) Productive infection was detected by flow cytometry of EGFP expression following infection with NL4.3-Δnef/EGFP (one donor). The integrated copies of HIV per million cells are shown for this donor (right hand panel). SSC = side scatter.