Induced tetherin in mature DCs has different effects on WT and Vpu-deleted HIV-1 replication and DC-mediated HIV-1 transmission to CD4+ T cells. (A and B) The effect of tetherin on HIV-1 replication in mature DCs was assessed by tetherin knockdown and infection with WT NL(AD8) or NL(AD8)ΔVpu. Supernatant p24 in mDC-LPS (A) or mDC-IFNα (B) nucleofected with tetherin-specific siRNA or a non-silencing (NS) scramble siRNA control were assessed by p24 ELISA at 5 days post-infection. (C and D) The effect of tetherin on cell-to-cell transmission of WT NL(AD8) or NL(AD8)ΔVpu from tetherin-specific or NS siRNA nucleofected mDC-LPS (C) or mDC-IFNα (D) to Hut/CCR5 cells. Supernatants were collected after 2 days of co-culture and p24 concentration was assessed by ELISA. Graphs represent data from one donor representative of at least two experiments performed on DCs from different donors. Data are presented as mean ± SEM of duplicate samples.