DC-SIGN⁺ blood DCs transmit HIV-1 to responder T cells.

Monocytes (mono), DC-SIGN⁺ blood DCs, CD4⁺blood DCs (all from the same donor), and immature (imm) monocyte-derived DCs were incubated with low amounts of HIV-1 in the presence or absence of blocking antibodies to DC-SIGN (AZN-D1, 20 μg/mL) and subsequently cocultured with PHA/IL-2–activated CD4⁺ T cells for 7 days (A) or for the time points indicated (B). As a control, T cells alone were incubated with HIV-1. Levels of p24 were determined by ELISA in the supernatants. A representative experiment (of 2 experiments) is shown.