Cdc42 silencing in DCs prevents HIV-1 fusion in target T lymphocytes. (A) Confocal microscope analysis of HIV-1 fusion in target CD4⁺ T lymphocytes. Nontreated (left panels) and siCdc42 (right panels) conditions are represented. Fused viral particles (green only) are shown by arrows. Bar represents 5 μm. (B) Live imaging analysis of HIV-1 transfer across DC-CD4⁺ T cell infectious synapses. (Left panel) Infectious synapse analyzed in supplemental Video 1. *DCs. **CD4⁺ T cells. Bar represents 2 μm. Right panel demonstrates time points during HIV-1 transfer across DC-CD4⁺ T cell infectious synapse shown in supplemental Video 1. White arrow indicates a static point along HIV-1 transfer trajectory. (C) Different examples of HIV-1 transfer trajectories across DC-CD4⁺ T cell infectious synapses. *DCs. **CD4⁺ T cells. *P < .05 (Student t test).