SIV Envelope Acquires a Nefarious Habit

Deletion of the nef gene from macaque simian immunodeficiency virus (SIVmac) attenuates its ability to cause disease. Pathogenic viruses occasionally emerge in macaques infected with Nef-deleted SIVmac, with some genetic determinants mapping to the envelope (env) gene. An intriguing new study shows that these changes endow Env with a Nef-like ability to counteract tetherin/BST2 (Serra-Moreno et al., 2011)