22 December 2010
Vol 2, Issue 63

About The Cover

Cover image expansion

ONLINE COVER Blocking HIV Entry. An HIV-1 virion is prevented from anchoring to the host cell membrane by the peptide drug VIR-576 (red). VIR-576 binds to the fusion peptide (pale yellow) of the viral transmembrane protein gp41 (green). HIV virions gain entry to their target host cells (usually CD4+ T lymphocytes) in a multi-step process: the gp120 viral protein (blue) docks first to CD4 (ochre) and next to a co-receptor (brown) on the host cell membrane; this enables gp41 (green trimer) to be positioned so that the fusion peptide (pale yellow) at its tip can be inserted into the host cell membrane allowing the two membranes to fuse. It is this insertion step that is blocked by VIR-576, the first of a new class of HIV entry inhibitor. In their proof-of-concept study, Forssmann, Kirchhoff and colleagues show that the VIR-576 peptide is able to block virus replication and reduce viral load in HIV-infected patients. [CREDIT: C. BICKEL/SCIENCE TRANSLATIONAL MEDICINE]