This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Odawara, T.
Right arrow Articles by Yoshikura, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Odawara, T.
Right arrow Articles by Yoshikura, H.

 Previous Article  |  Next Article 

J Virol, July 1998, p. 5414-5424, Vol. 72, No. 7
0022-538X/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Threshold Number of Provirus Copies Required per Cell for Efficient Virus Production and Interference in Moloney Murine Leukemia Virus-Infected NIH 3T3 Cells

Takashi Odawara,1,* Masamichi Oshima,1 Kent Doi,1 Aikichi Iwamoto,2 and Hiroshi Yoshikura1

Department of Bacteriology, Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113,1 and Department of Infectious Diseases, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108,2 Japan

Received 2 October 1997/Accepted 23 March 1998

The gag-pol readthrough mutant of Moloney murine leukemia virus, MLV-B(CAG) (T. Odawara, H. Yoshikura, M. Oshima, T. Tanaka, D. S. Jones, F. Nemoto, Y. Kuchino, and A. Iwamoto, J. Virol. 65:6376-6379, 1991), was poorly complemented by a mutant encoding only Gag. This is because with all the genetic elements necessary for env expression present in MLV-B(CAG), insufficient Env protein was produced by the cells expressing MLV-B(CAG) for efficient virus production. Since the env mRNA expression per provirus in the MLV-B(CAG)- and wild-type-MLV-producing cells were the same and since the cells expressing the former contained eightfold fewer proviral copies, the insufficient Env expression by the former was found to be due to insufficient proviral copies in the cells. Examination of the cell clones having various proviral copies of Delta wt MLV (M. Oshima, T. Odawara, T. Matano, H. Sakahira, Y. Kuchino, A. Iwamoto, and H. Yoshikura, J. Virol. 70:2286-2295, 1996) showed that mRNA level was proportional to the number of proviral copies while interference and virus production followed a sigmoid curve with a sharp rise at the threshold number of proviral copies of around four per cell. Multicycle infection probably continues until the threshold level of proviral copies is attained in natural infection too.

* Corresponding author. Present address: AIDS Research Center, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan. Phone: 81-42-561-0771, ext. 370. Fax: 81-42-567-5632. E-mail: tako{at}nih.go.jp.

J Virol, July 1998, p. 5414-5424, Vol. 72, No. 7
0022-538X/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Yap, M. W., Kingsman, S. M., Kingsman, A. J. (2000). Effects of stoichiometry of retroviral components on virus production. J. Gen. Virol. 81: 2195-2202 [Abstract] [Full Text]  
  • Szurek, P. F., Brooks, B. R. (2000). Synthesis of Virus-Specific High-Mobility DNA after Temperature Upshift of SC-1 Cells Chronically Infected with Moloney Murine Leukemia Virus Mutant ts1. J. Virol. 74: 7055-7063 [Abstract] [Full Text]  
  • Young, W.-B., Link, C. J. Jr. (2000). Chimeric Retroviral Helper Virus and Picornavirus IRES Sequence To Eliminate DNA Methylation for Improved Retroviral Packaging Cells. J. Virol. 74: 5242-5249 [Abstract] [Full Text]  
  • Young, W.-B., Lindberg, G. L., Link, C. J. Jr. (2000). DNA Methylation of Helper Virus Increases Genetic Instability of Retroviral Vector Producer Cells. J. Virol. 74: 3177-3187 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»