Figure 8.

Infectious LV Formation by Admixing Unenveloped LV with Exogenous G

(A) Non-infectious unenveloped LVs encoding GFP were mixed with supernatant collected from cells transiently expressing vesiculovirus G proteins (VSVind, COCV, and PIRYV) at a 1:3 v/v ratio, incubated at 37°C for 1 hr, and plated onto HEK293T cells. Percentages of GFP-positive cells were measured 48 hr thereafter via flow cytometry. Cell supernatant COCV.G and PIRYV.G, albeit slightly less efficiently than VSVind.G, made env-less LV infectious. (B) The same could be achieved using supernatant collected from WinPac-GFP and stable envelope-expressing cells. The titers achieved by admixing were comparable or better than LVs produced via transient transfection of envelope expression plasmids into the bulk WinPac-GFP cell population. The data shown represent mean titers ± SD for three experiments performed in duplicate.