The cytoplasmic tail substitution increases the assembly efficiency of Ebola virus glycoprotein on the budded virus of Bombyx mori nucleopolyhedrovirus.

Glycoprotein (GP1,2) of the Ebola virus (EBOV) is the key membrane fusion protein, which is a key candidate protein for vaccine preparations. Previously, GP1,2 was expressed by Bombyx mori nucleopolyhedrovirus (BmNPV) expression vector system; however, few GP1,2 was incorporated into budded virus (BV) of BmNPV. To improve the incorporation efficiency of GP1,2 into the virion, the GP1,2 fusion with the cytoplasmic tail of GP64 of BmNPV was expressed in BmN cells by the BmNPV expression system. The BV was purified by ultracentrifugation, and GP1,2 expression in BV was detected by the antibody. The result indicated that a 532% increase in the relative GP1,2 densitometry signal was observed in constructs utilizing the GP64 C-terminal domain; moreover, the substitution of GP1,2 native signal peptide with GP64 signal peptide increased the incorporation efficiency by 34.6% in the relative GP1,2 densitometry signal. We revealed that the application of the cytoplasmic tail of BmNPV GP64 significantly increased the incorporation rate of GP1,2 into the BV envelope. This study lays a foundation for GP1,2 vaccine development.