Reconstituting HIV Replication in a Test Tube

Reverse transcription and integration are key events in retrovirus replication and are also targets of successful anti-HIV therapies. Reverse transcription creates a double-stranded DNA copy of the viral RNA genome, and integration archives that copy within the genome of the infected cell. However, studies of the mechanisms underlying these steps of the viral life cycle remain challenging because these processes are performed by viral core particles located deep within the infected cell cytoplasm and nucleus. To address this limitation, University of Utah Health investigator Wesley Sundquist, PhD, and colleagues reconstituted efficient HIV reverse transcription and integration in a cell-free system. They showed that the system responds appropriately to antiviral compounds. They also discovered that the viral capsid (the protein shell of a virus) plays an active role in supporting efficient reverse transcription. Thus, the entire core particle, including the outer capsid shell, is the true viral "replication complex". This cell-free system is expected to enable new systematic analyses of viral replication and integration and thus help shed light on the first half of the viral life cycle.