Antibody sources and conditions.

Autophagy is part of the innate immune arsenal to fight viruses, including HIV-1. We previously reported that HIV-1 Gag is targeted for autophagy-mediated degradation. Here, we identify HIV-1 Vpr, an important virulence factor, as an autophagy target in HIV-1 NL4–3, a lab adapted molecular clone. Notably, Vpr proteins from a collection of transmitted/founder viruses (TFVs) were resistant to autophagy. Based on this observation, we identified residues at positions 37, 45, 77, 83–86, 93–94 in NL4–3 Vpr as responsible for its susceptibility to autophagy. Importantly, differences between NL4–3 and TFV Vpr proteins at these positions impact their interaction with the autophagy receptors NDP52, SQSTM1/p62 and TAX1BP1. By engineering NL4–3 molecular clones harboring either autophagy-sensitive or -resistant vpr, we found that in 2D and 3D in vitro systems virus spread was significantly reduced for the virus carrying autophagy-sensitive Vpr. In conclusion, our study identifies Vpr as a novel autophagy target and suggests that Vpr susceptibility to autophagy impacts HIV-1 spread.