Transduction of vertebrate cells with Spodoptera exigua multiple nucleopolyhedrovirus F protein-pseudotyped gp64-null Autographa californica multiple nucleopolyhedrovirus.

Budded virions of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) can enter a variety of non-host cells. The capacity of GP64, AcMNPV's endogenous envelope fusion protein, and SeF, the fusion protein from a gp64(-) baculovirus, to mediate baculovirus entry into vertebrate cells was examined by comparing the transduction efficiencies of engineered AcMNPV variants with either of the two envelope proteins into 17 vertebrate cell lines. At an m.o.i. of 500, GP64-expressing viruses transduced all cell lines with varying efficiencies. Transduction efficiencies of SeF-pseudotyped gp64-null AcMNPV into all cell lines were lower than those of GP64-expressing viruses, and were undetectable in seven cell lines. At an m.o.i. of 50, transduction of all mammalian cell lines transducible by the SeF-pseudotyped gp64-null AcMNPV at an m.o.i. of 500 was no longer detectable. An amplifiable SeF-pseudotyped gp64-null AcMNPV vector with greatly reduced tropism for vertebrate cells may have applications in engineering AcMNPV for targeted transduction.