This Article Full Text Full Text (PDF) Other Versions of this Article: JVI.00662-08v1 82/14/6942    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Suzuki, R. Articles by Mason, P. W. PubMed PubMed Citation Articles by Suzuki, R. Articles by Mason, P. W.

 Previous Article  |  Next Article 

Journal of Virology, July 2008, p. 6942-6951, Vol. 82, No. 14
0022-538X/08/$08.00+0     doi:10.1128/JVI.00662-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Identification of Mutated Cyclization Sequences That Permit Efficient Replication of West Nile Virus Genomes: Use in Safer Propagation of a Novel Vaccine Candidate

Department of Pathology,¹ Department of Microbiology and Immunology,² University of Texas Medical Branch, Galveston, Texas 77555, and Department of Virology II, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, 162-8640, Japan³

Received 25 March 2008/ Accepted 28 April 2008

Existing live-attenuated flavivirus vaccines (LAV) could be improved by reducing their potential to recombine with naturally circulating viruses in the field. Since the highly conserved cyclization sequences (CS) found in the termini of flavivirus genomes must be complementary to each other to support genome replication, we set out to identify paired mutant CS that could support the efficient replication of LAV but would be unable to support replication in recombinant viruses harboring one wild-type (WT) CS. By systematic evaluation of paired mutated CS encoded in West Nile virus (WNV) replicons, we identified variants having single and double mutations in the 5'- and 3'-CS components that could support genome replication at WT levels. Replicons containing only the double-mutated CS in the 5' or the 3' ends of the genome were incapable of replication, indicating that mutated CS could be useful for constructing safer LAV. Despite the identity of the central portion of the CS in all mosquito-borne flaviviruses, viruses carrying complementary the double mutations in both the 5'- and the 3'-CS were indistinguishable from WT WNV in their replication in insect and mammalian cell lines. In addition to the utility of our novel CS pair in constructing safer LAV, we demonstrated that introduction of these mutated CS into one component of a recently described two-component genome system (A. V. Shustov, P. W. Mason, and I. Frolov, J. Virol. 81:11737-11748, 2007) enabled us to engineer a safer single-cycle WNV vaccine candidate with reduced potential for recombination during its propagation.

Published ahead of print on 14 May 2008.