FIG. 4.
Early and late transfer of HIV-1 particles by IM-MDDCs. (A) Schematic representation showing early- and late-transfer processes of HIV-1 by DCs. iDC, immature DCs. (B) IM-MDDCs (1 × 105 cells) were either left untreated (empty bars) or treated with the antiviral agent AZT (10 μM; filled bars) for 10 min. The cells were then pulsed for 60 min with similar concentrations of isogenic NL4-3balenv either lacking or bearing host-encoded LFA-1 (10 ng p24Gag). After three washes with PBS, the cell-virus mixture was divided into three aliquots and cocultured with autologous CD4+ T cells at a DC-to-T-cell ratio of 1:3. Virus production was determined by measuring p24Gag levels in the culture supernatants at day 3 following initiation of the coculture. (C) The late transfer phase was assayed as follows. First, IM-MDDCs (5 × 105 cells) were pulsed with similar concentrations of isogenic NL4-3balenv either lacking or bearing host-encoded LFA-1 (50 ng p24Gag). Next, 5 days later, IM-MDDCs were cocultured with autologous CD4+ T cells at a DC-to-T-cell ratio of 1:3. Virus production was determined by measuring p24Gag levels in the culture supernatants at day 6 following initiation of the coculture. The data shown are the means ± the SDs of the results for triplicate samples and are representative of three independent experiments. *, P < 0.05; **, P < 0.01.