Involvement of DCIR in HIV-1 transmission by IM-MDDCs. IM-MDDCs (1 × 10⁶ cells) were treated with oligofectamine and then either left untreated (control) or exposed to a nonspecific siRNA and a DCIR-specific siRNA. Next, cells (1 × 10⁵) were pulsed with NL4-3balenv (10 ng p24) for 60 minutes at 37°C. After 3 washes with PBS to eliminate unbound virus, IM-MDDCs were cocultured with autologous CD4⁺ T cells at a 1:3 ratio. Cell-free culture supernatants were collected at day 2 following initiation of the coculture and analyzed for the p24 content. Data shown represent the means (+ SD) of triplicate samples from 3 combined independent experiments. Asterisks denote statistically significant data (***P < .001).