Autor(es): Xie Xuping, Wang Qing-Yin, Xu Hao Ying, Qing Min, Kramer Laura, Yuan Zhiming, Shi Pei-Yong

Resumo: We report a novel inhibitor that selectively suppresses dengue virus (DENV) by targeting viral NS4B protein. The inhibitor was identified by screening a 1.8-million-compound library using a luciferase replicon of DENV serotype 2 (DENV-2). The compound specifically inhibits all four serotypes of DENV (50% effective concentration [EC(50)], 1 to 4 ?M; - 50% cytotoxic concentration [CC(50)], >40 ?M), but it does not inhibit closely related flaviviruses (West Nile virus - yellow fever virus) or nonflaviviruses (Western equine encephalomyelitis virus, Chikungunya virus, - vesicular stomatitis virus). A mode-of-action study suggested that the compound inhibits viral RNA synthesis. Replicons resistant to the inhibitor were selected in cell culture. Sequencing of the resistant replicons revealed two mutations (P104L - A119T) in the viral NS4B protein. Genetic analysis, using DENV-2 replicon - recombinant viruses, demonstrated that each of the two NS4B mutations alone confers partial resistance - double mutations confer additive resistance to the inhibitor in mammalian cells. In addition, we found that a replication defect caused by a lethal NS4B mutation could be partially rescued through trans complementation. The ability to complement NS4B in trans affected drug sensitivity when a single cell was coinfected with drug-sensitive - drug-resistant viruses. Mechanistically, NS4B was previously shown to interact with the viral NS3 helicase domain; one of the two NS4B mutations recovered in our resistance analysis-P104L-abolished the NS3-NS4B interaction (I. Umareddy, A. Chao, A. Sampath, F. Gu, - S. G. Vasudevan, J. Gen. Virol. 87:2605-2614, 2006). Collectively, the results suggest that the identified inhibitor targets the DENV NS4B protein, leading to a defect in viral RNA synthesis.

Imprenta: Journal of Virology, v. 85, n. 21, p. 11183-11195, 2011

Identificador do objeto digital: 10.1128/JVI.05468-11

Descritores: Chikungunya virus - Biosynthesis ; Chikungunya virus - Cell ; Chikungunya virus - DNA ; Chikungunya virus - Flaviviridae ; Chikungunya virus - Pathogenesis ; Chikungunya virus - Protein synthesis ; Chikungunya virus - Proteins ; Chikungunya virus - RNA ; Chikungunya Virus - Virus ; Chikungunya virus - Chikungunya fever ; Chikungunya virus - Dengue

Data de publicação: 2011