BST2 and infection: Similar to low dose infection, high dose infection of hu-mice revealed a Vpu-dependent down regulation of BST2 at the cell surface of infected cells and an initial burst of viral replication and propagation, although the difference in plasma viremia between HIV-1-WT and HIV-1-∆Vpu infected animals (~15-fold at 21-dpi) was not as significant compared to those infected with low dose at early time points (~150-fold at 4-wpi) (Figures 2 and 3).