The distribution of VCCs is dependent on the integrity of the microtubule network. (A) Ultrathin cryosections of macrophages infected with HIV-1 NLAD8 for 15 d were prepared and labeled with anti-Env antibodies and protein A coupled to gold particles of 10-nm diameter (PAG10) and with anti-Pr55Gag antibodies and PAG15. Arrowheads point to viral particles in the process of budding. Bar, 200 nm. (B) 3D reconstruction of macrophages infected with HIV-1 NLAD8 for 7 d and stained for Gag (see Video 1). (C) Confocal micrographs (one plane) of HIV-1–infected macrophages exposed to DMSO or nocodazole (10 µM) for 1 h. Cells were fixed and stained with antibodies specific for the indicated proteins. Bar, 5 µm. These experiments have been repeated three times. (D) Ultrathin cryosections of macrophages infected with HIV-1 NLAD8 for 15 d were double-immunogold labeled for Pr55Gag with PAG15 and for α-tubulin with PAG10. Three representative profiles are presented. Tubulin staining was present at the limiting membrane of VCCs (see arrowheads). Bars, 200 nm.