[New virological data: replication and persistence of the human immunodeficiency virus]

Human immunodeficiency virus behaves in vitro as an acutely replicating, cytopathic retrovirus. However, HIV infection in vivo is persistent and slowly progressive. Many virological properties of HIV could be involved in establishing the persistence of infection: the complex regulation of HIV replication, particularly of HIV gene expression; the requirement of cell activation for several steps of HIV replication; the role of HIV accessory genes; the great genetic variability of HIVs, allowing their adaptation to host responses in vivo.