JAC Advance Access first published online on November 5, 2009
This version published online on November 9, 2009
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dkp393
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Original research |
BPR2-D2 targeting viral ribonucleoprotein complex-associated function inhibits oseltamivir-resistant influenza viruses
1 Division of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli, Taiwan 2 Research Center for Emerging Viral Infections, Tao-Yuan, Taiwan 3 Department of Medical Biotechnology & Laboratory Science, Chang Gung University, Tao-Yuan, Taiwan 4 Clinical Virology Laboratory, Chang-Gung Memorial Hospital, Tao-Yuan, Taiwan 5 Department of Biochemistry and Molecular Biology, Chang Gung University, Tao-Yuan, Taiwan 6 Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China 7 Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
Received 13 June 2009; returned 20 July 2009; revised 7 October 2009; accepted 8 October 2009
* Corresponding author. Department of Medical Biotechnology and Laboratory Science, Chang Gung University, 259 Wen-Hua 1st Rd, Kwei-Shan, Taoyuan, 333, Taiwan. Tel: +886-3-2118800, ext. 5497; Fax: +886-3-2118174; E-mail: srshih{at}mail.cgu.edu.tw
Objectives: The emergence of oseltamivir-resistant viruses raised the global threat with regard to influenza virus infection. To develop alternative antiviral agents against influenza virus infection is significant and urgent.
Methods: A neutralization test was applied as a screening assay and a plaque reduction assay was used for confirmation. Expression plasmids for viral ribonucleoproteins (RNPs) and a plasmid that allowed expression of a pseudoviral reporter RNA were transfected into cells to investigate the effects of a novel antiviral compound on viral RNA synthesis.
Results: BPR2-D2 was identified as a novel inhibitor against influenza virus from a hit obtained from high throughput screening of 20 000 or more compounds. BPR2-D2 exhibited an excellent antiviral efficacy for the oseltamivir-resistant virus (EC50 ranging from 0.021 to 0.040 µM). No resistant virus was produced throughout 20 passages in the presence of BPR2-D2, whereas oseltamivir-resistant virus was generated at passage 8 using the same experimental system. A molecular target other than neuraminidase (NA) was found because BPR2-D2 inhibited the synthesis of viral RNA that was driven by influenza viral RNP in a transfection assay. BPR2-D2 also exhibited a broad antiviral spectrum against various strains of influenza A and influenza B viruses.
Conclusions: BPR2-D2 was identified as a novel inhibitor of influenza virus. It may target viral RNPs that are responsible for viral RNA synthesis. Targeting different molecules compared with NA allows BPR2-D2 to inhibit oseltamivir-resistant viruses.
Key Words: antiviral agent , viral RNA , influenza A virus
The first and second authors contributed equally to this work. The original version was incorrect. There should have been an additional footnote stating that the first and second authors contributed equally to this work.