The significance of controlled conditions in lentiviral vector titration and in the use of multiplicity of infection (MOI) for predicting gene transfer events

Zhang, B., Metharom, P., Jullie, H., Ellem, K. A. O., Cleghorn, Geoffrey J., West, M. J., & Wei, M. Q. (2004) The significance of controlled conditions in lentiviral vector titration and in the use of multiplicity of infection (MOI) for predicting gene transfer events. Genetic Vaccines and Therapy, 2(1), p. 6.

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Abstract

Background: Although lentiviral vectors have been widely used for in vitro and in vivo gene therapy researches, there have been few studies systematically examining various conditions that may affect the determination of the number of viable vector particles in a vector preparation and the use of Multiplicity of Infection (MOI) as a parameter for the prediction of gene transfer events. Methods: Lentiviral vectors encoding a marker gene were packaged and supernatants concentrated. The number of viable vector particles was determined by in vitro transduction and fluorescent microscopy and FACs analyses. Various factors that may affect the transduction process, such as vector inoculum volume, target cell number and type, vector decay, variable vector - target cell contact and adsorption periods were studied. MOI between 0-32 was assessed on commonly used cell lines as well as a new cell line. Results: We demonstrated that the resulting values of lentiviral vector titre varied with changes of conditions in the transduction process, including inoculum volume of the vector, the type and number of target cells, vector stability and the length of period of the vector adsorption to target cells. Vector inoculum and the number of target cells determine the frequencies of gene transfer event, although not proportionally. Vector exposure time to target cells also influenced transduction results. Varying these parameters resulted in a greater than 50-fold differences in the vector titre from the same vector stock. Commonly used cell lines in vector titration were less sensitive to lentiviral vector-mediated gene transfer than a new cell line, FRL 19. Within 0-32 of MOI used transducing four different cell lines, the higher the MOI applied, the higher the efficiency of gene transfer obtained. Conclusion: Several variables in the transduction process affected in in vitro vector titration and resulted in vastly different values from the same vector stock, thus complicating the use of MOI for predicting gene transfer events. Commonly used target cell lines underestimated vector titre. However, within a certain range of MOI, it is possible that, if strictly controlled conditions are observed in the vector titration process, including the use of a sensitive cell line, such as FRL 19 for vector titration, lentivector-mediated gene transfer events could be predicted. © 2004 Zhang et al; licensee BioMed Central Ltd.

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ID Code: 89444
Item Type: Journal Article
Refereed: Yes
Additional Information: Cited By :28
Export Date: 1 September 2015
Correspondence Address: Wei, M.Q.; Department of Medicine, University of Queensland, Prince Charles Hospital, Brisbane, QLD, Australia; email: d.wei@mailbox.uq.edu.au
Keywords: lentivirus vector, animal cell, article, cell count, cell type, controlled study, fluorescence activated cell sorting, fluorescence microscopy, gene transfer, genetic transduction, human, human cell, in vitro study, inoculation, marker gene, nonhuman, prediction, supernatant, target cell, virus adsorption, virus titration
DOI: 10.1186/1479-0556-2-6
ISSN: 1479-0556
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Current > Schools > School of Exercise & Nutrition Sciences
Deposited On: 26 Oct 2015 01:10
Last Modified: 26 Oct 2015 01:10

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