𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Growth factor displayed on the surface of retroviral particles without manipulation of envelope proteins is biologically active and can enhance transduction

✍ Scribed by Anil Chandrashekran; Myrtle Y. Gordon; David Darling; Farzin Farzaneh; Colin Casimir


Book ID
102337612
Publisher
John Wiley and Sons
Year
2004
Tongue
English
Weight
312 KB
Volume
6
Category
Article
ISSN
1099-498X

No coin nor oath required. For personal study only.

✦ Synopsis


Abstract

Background

The therapeutic potential of retroviruses can be significantly enhanced by display of specific molecules on the retroviral surface. This has been conventionally achieved by the manipulation of retroviral envelope proteins. In this report we have tested whether the natural budding mechanism of the retrovirus could be exploited to incorporate a specific molecule into the retroviral surface.

Methods

Retroviral packaging cells were engineered to express the membrane‐bound form of human stem cell factor (mbSCF). Surface expression of mbSCF on retroviral packaging cells was confirmed by immunofluorescence and flow cytometry. Incorporation of mbSCF into retroviral particles was demonstrated by virus‐binding assay and immunomagnetic capture of virus using antibody to SCF. Retroviral supernatants were tested for activity of the incorporated cytokine by proliferation assays on factor‐dependent cells. Amphotropic retrovirus displaying surface mbSCF was used to transduce SCF receptor‐positive haematopoietic cells.

Results

Retroviruses incorporating surface SCF showed increased levels of binding to cells (MO7e) expressing the SCF receptor, c‐kit. mbSCF displayed on the viral surface retained levels of biological activity comparable with those of soluble recombinant growth factor. Transduction of c‐kit‐positive target cells with viruses displaying mbSCF showed enhanced levels of transduction in comparison with unmodified viruses.

Conclusions

Expression of the membrane‐bound form of human stem cell factor (mbSCF) on the surface of retroviral packaging cells allows its efficient incorporation into retrovirus particles in a biologically active form, opening up the possibility for the use of retroviral display in many therapeutic areas, such as in gene therapy, drug delivery and in the development of novel vaccines. Copyright © 2004 John Wiley & Sons, Ltd.