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 Google Scholar
Google Scholar
Right arrow Articles by Gates, I. V.
Right arrow Articles by Bodmer, J.-L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gates, I. V.
Right arrow Articles by Bodmer, J.-L.
Agricola
Right arrow Articles by Gates, I. V.
Right arrow Articles by Bodmer, J.-L.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, April 2009, p. 2027-2036, Vol. 75, No. 7
0099-2240/09/$08.00+0     doi:10.1128/AEM.02006-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Quantitative Measurement of Varicella-Zoster Virus Infection by Semiautomated Flow Cytometry{triangledown}

Irina V. Gates,1,{dagger} Yuhua Zhang,3 Cindy Shambaugh,1,§ Meredith A. Bauman,1,4 Charles Tan,3 and Jean-Luc Bodmer1,2*

Fermentation and Cell Culture,1 Vaccine Basic Research,2 Non-Clinical Statistics, Merck Research Laboratories, Merck & Co., Inc., 770 Sumneytown Pike, West Point, Pennsylvania 19486,3 Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 212184

Received 29 August 2008/ Accepted 28 January 2009

Varicella-zoster virus (VZV; human herpesvirus 3) is the etiological cause of chickenpox and, upon reactivation from latency, zoster. Currently, vaccines are available to prevent both diseases effectively. A critical requirement for the manufacturing of safe and potent vaccines is the measurement of the biological activity to ensure proper dosing and efficacy, while minimizing potentially harmful secondary effects induced by immunization. In the case of live virus-containing vaccines, such as VZV-containing vaccines, biological activity is determined using an infectivity assay in a susceptible cellular host in vitro. Infectivity measurements generally rely on the enumeration of plaques by visual inspection of an infected cell monolayer. These plaque assays are generally very tedious and labor intensive and have modest throughput and high associated variability. In this study, we have developed a flow cytometry assay to measure the infectivity of the attenuated vaccine strain (vOka/Merck) of VZV in MRC-5 cells with improved throughput. The assay is performed in 96-well tissue culture microtiter plates and is based on the detection and quantification of infected cells expressing VZV glycoproteins on their surfaces. Multiple assay parameters have been investigated, including specificity, limit of detection, limit of quantification, range of linear response, signal-to-noise ratio, and precision. This novel assay appears to be in good concordance with the classical plaque assay results and therefore provides a viable, higher-throughput alternative to the plaque assay.

* Corresponding author. Mailing address: Merck Research Laboratories, Vaccine Basic Research, WP26A-4000, 770 Symneytown Pike, West Point, PA 19486. Phone: (215) 652-6502. Fax: (215) 652-2439. E-mail: jean_luc_bodmer{at}merck.com

{triangledown} Published ahead of print on 5 February 2009.

{dagger} Present address: Centocor Inc., 145 King of Prussia Road, Radnor, PA 19087.

§ Present address: MedImmune, 319 Bernardo Ave., Mountain View, CA 94043.

Applied and Environmental Microbiology, April 2009, p. 2027-2036, Vol. 75, No. 7
0099-2240/09/$08.00+0     doi:10.1128/AEM.02006-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.





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