Tetherin restricts direct cell-cell viral transfer and transmission of HIV-1

Excerpt

Tetherin (BST-2/CD317/HM1.24) is an interferon-inducible factor of the innate immune system, recently shown to exert antiviral activity against HIV-1 and other enveloped viruses by tethering nascent viral particles to the cell surface, thereby inhibiting viral release. In HIV-1 infection, the viral protein U (Vpu) counteracts this antiviral action by down-modulating tetherin from the cell surface. Viral transmission between T cells can occur via cell-free transmission or the more efficient direct cell-cell route through virological synapses. Virological synapses are associated with lipid raft-rich microdomains in the membrane. Tetherin is known to localize to these microdomains and is capable of modulating actin architecture, which is crucial for viral entry, assembly and budding. …