Ebolavirus replication and Tetherin/BST-2

• Main Author: Jiro eYasuda
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2012-04-01
• Series: Frontiers in Microbiology
• Subjects: Ebolavirus; VLP; antagonist; GP; Tetherin/BST-2
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fmicb.2012.00111/full

Ebolavirus (EBOV) is an enveloped, non-segmented, negative-stranded RNA virus, which consists of five species: Zaire ebolavirus (ZEBOV), Sudan ebolavirus (SEBOV), Tai Forest ebolavirus (TFEBOV), Bundibugyo ebolavirus (BEBOV), and Reston ebolavirus (REBOV). EBOV causes a lethal hemorrhagic fever in both humans and nonhuman primates. The EBOV RNA genome encodes seven viral proteins: NP, VP35, VP40, GP, VP30, VP24, and L. VP40 is a matrix protein and is essential for virus assembly and release from host cells. Expression of VP40 in mammalian cells is sufficient to generate extracellular virus-like particles (VLPs), which resemble authentic virions. Tetherin/BST-2, which was identified as an effective cellular factor that prevents HIV-1 release in the absence of viral accessory protein Vpu, has been reported to inhibit ZEBOV VP40-induced VLP release. Tetherin/BST-2 appears to inhibit virus release by physically tethering viral particles to the cell surface via its N-terminal transmembrane domain and C-terminal GPI anchor. Replication of ZEBOV is not inhibited by Tetherin/BST-2 expression, although Tetherin/BST-2 was expected to inhibit EBOV release as well as VLP release. Recently, it was reported that viral surface glycoprotein of EBOV, GP, antagonizes the antiviral effect of Tetherin/BST-2. However, the mechanism by which GP antagonizes the antiviral activity of Tetherin/BST-2 and whether GP of the other EBOV species function as antagonists of Tetherin/BST-2 remain unclear.