Advances in basic science.

Basic science continues to occupy a substantial portion of the program at the Conference on Retroviruses and Opportunistic Infections. At the 17th conference this year, presentations focused on advances in our understanding of cellular factors that regulate the interplay between the virus and the host cell and, in particular, cellular defenses such as tetherin (or BST-2) that antagonize viral replication. Research into basic mechanisms of primate lentiviral pathogenicity was also an area of great interest at the conference. An analysis of the evolution of lentiviral and primate genomes highlights the conflict between the virus and its host and illustrates the considerable gyrations that lentiviruses have undergone to acquire the ability to replicate within their primate hosts. It is now apparent that all 4 accessory proteins of lentiviruses are in some way involved in overcoming natural antiviral restrictions in primate cells. Therefore, because lentiviruses such as HIV-1 are hard pressed to avoid the intrinsic antiviral defenses of the cell, there is strong rationale for the development of strategies that harness the antiviral capacity of these natural cellular restrictions.