The human immunodeficiency virus-1 (HIV-1) produces Vif (virion infectivity factor) proteins that are potent viral regulators, but the mechanisms that regulate virion production in humans has been unclear. In 14 July advanced online Nature, Ann Sheehy and colleagues at the University of Pennsylvania School of Medicine and King's College London, show that the human gene CEM15 could inhibit HIV-1 infection of T cells but viral Vif suppresses CEM15 expression (Nature 2002, DOI:10.1038/nature00939).

Sheehy et al. used a DNA subtraction strategy based on polymerase chain reaction in different T cell lines and identified a unique cellular gene, CEM15 — an RNA editing enzyme and a target for Vif. They observed that transient or stable expression of CEM15 in cells that do not normally express this gene renders progeny virions non-infectious, but this antiviral action is overcome by the presence of Vif.

These results suggest that molecules that...