Capillary-like vascular micro-tubule formation in HHV8-infected and control HUVEC cells. HUVEC cells were infected with HHV8 as described in Figure 1. 24 h before the indicated times, 3.0 × 104 cells were seeded in plates previously coated with Geltrex matrix and cultured in a complete or serum-free M200 medium in a CO2 incubator at 37°C. The specific ACAT inhibitor Sandoz 58035 (SZ, 4 μM) was added in some experimental groups. Capillary-like microtubule formation in the control and HHV8-infected HUVEC cells was performed as described in the Methods section. Panel A shows the light microscope images of micro-tubule formation in control, lytic and latent HHV8-infected HUVEC cells cultured in medium with or without (W/O) fetal calf serum (FCS). The bar in the figure is 240 μm. Panel B represents the angiogenic index quantification (for details, see Methods). All the samples were prepared in triplicate and the experiments were repeated at least twice. Data were reported as mean ± SE. Significance was set up when p < 0.05 (*) or p < 0.001 (***) vs. respective control (t-test).