Vpu channel blockers inhibit in vitro HIV-1 replication.
Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. A10255)
Ewart GD, Nasr N, Naif H, Cox GB, Cunningham AL, Gage PW Biotron Limited, Canberra, Australia
Newly assembled HIV-1 virions emerge from the plasma membrane of infected cells by a process known as "budding" that involves co-ordinated interactions between viral and cellular components. Budding is fundamental to HIV-1 replication and the proteins involved in this process represent potential targets for novel anti-viral therapeutic drugs. The Gag polyprotein is the primary viral protein that drives budding and in experimental systems, expression of Gag in the absence of other viral genes leads to the assembly and release of virus-like particles (VLP). The HIV-1 accessory protein Vpu enhances budding by an unknown mechanism that is associated with its ability to form an ion channel. The co-incident inhibitory effects of site-directed mutations and small molecule channel blockers provided evidence for the involvement of the Vpu ion channel activity in the budding process. At Biotron Limited, we initially discovered that amiloride analogues 5-(N,N-hexamethylene)amiloride (HMA) and 5-(N,N-dimethyl)amiloride (DMA) inhibit both the Vpu ion channel and VLP budding from HeLa cells expressing HIV-1 Gag and Vpu. Amiloride itself does not inhibit either of those Vpu-associated activities. Recently, we have extended this work to show that HMA and DMA, but not amiloride, also inhibit at micromolar concentrations replication of the laboratory adapted macrophage tropic HIV-1BaL strain in macrophages cultured from human peripheral blood. While the therapeutic window is quite narrow for these two compounds, at concentrations below 10 micromolar the anti-viral activity of HMA and DMA is clearly dissociated from cytotoxicity. Our ongoing R&D efforts are directed at development of promising lead compounds towards a new class of clinically relevant anti-AIDS drugs that target virus budding.
Keywords: AEGIS, HIV-1, Virus Replication, Gene Products, gag, Anti-HIV Agents, Virion, Genes, gag, Acquired Immunodeficiency Syndrome, HIV Seropositivity, HIV, Macrophages, Viral Proteins, Hela Cells, Ion Channels, Genes, Viral, Humans, In Vitro, virology, genetics
