Factors that influence VSV-G pseudotyping and transduction efficiency of lentiviral vectors-in vitro and in vivo implications

Pseudotyping viral vectors with vesicular stomatitis virus glycoprotein (VSV‐G) enables the transduction of an extensive range of cell types from different species. We have discovered two important parameters of the VSV‐G‐pseudotyping phenomenon that relate directly to the transduction potential of lentiviral vectors: (1) the glycosylation status of VSV‐G, and (2) the quantity of glycoprotein associated with virions. We measured production‐cell and virion‐associated quantities of two isoform variants of VSV‐G, which differ in their glycosylation status, VSV‐G1 and VSV‐G2, and assessed the impact of this difference on the efficiency of mammalian cell transduction by lentiviral vectors. The glycosylation of VSV‐G at N336 allowed greater maximal expression of VSV‐G in HEK293T cells, thus facilitating vector pseudotyping. The transduction of primate cell lines was substantially affected (up to 50‐fold) by the degree of VSV‐G1 or VSV‐G2 incorporation, whereas other cell lines, such as D17 (canine), were less sensitive to virion‐associated VSV‐G1/2 quantities. These data indicate that the minimum required concentration of virion‐associated VSV‐G differs substantially between cell species/types. The implications of these data with regard to VSV‐G‐pseudotyped vector production, titration, and use in host‐cell restriction studies, are discussed. Copyright © 2007 John Wiley & Sons, Ltd.