@article{mbs:/content/journal/jgv/10.1099/vir.0.046458-0, author = "Shen, Shu and Gan, Yinyin and Wang, Manli and Hu, Zhihong and Wang, Hualin and Deng, Fei", title = "Incorporation of GP64 into Helicoverpa armigera nucleopolyhedrovirus enhances virus infectivity in vivo and in vitro", journal= "Journal of General Virology", year = "2012", volume = "93", number = "12", pages = "2705-2711", doi = "https://doi.org/10.1099/vir.0.046458-0", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.046458-0", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "The envelope fusion proteins of baculoviruses, glycoprotein GP64 from group I nucleopolyhedrovirus (NPV) or the F protein from group II NPV and granulovirus, are essential for baculovirus morphogenesis and infectivity. The F protein is considered the ancestral baculovirus envelope fusion protein, while GP64 is a more recent evolutionary introduction into baculoviruses and exhibits higher fusogenic activity than the F protein. Each of the fusion proteins is required by the respective virus to spread infection within larval tissues. A recombinant Helicoverpa armigera NPV (HearNPV) expressing GP64 from Autographa californica multiple nucleopolyhedrovirus, vHaBac-gp64-egfp, was constructed, which still retained the native F protein, and its infectivity was assayed in vivo and in vitro. Analyses by one-step growth curve to determine viral titre and by quantitative PCR to determine viral DNA copy number showed that vHaBac-gp64-egfp was more infectious in vitro than the control, vHaBac-egfp. The polyhedrin gene (polh) was reintroduced into the recombinant viruses and bioassays showed that vHaBac-gp64-polh accelerated the mortality of infected larvae compared with the vHaBac-egfp-polh control, and the LC50 (median lethal concentration) of vHaBac-gp64-polh was reduced to approximately 20 % of that of vHaBac-egfp-polh. Therefore, incorporation of GP64 into HearNPV budded virions improved virus infectivity both in vivo and in vitro. The construction of this bivalent virus with a more efficient fusion protein could improve the use of baculoviruses in different areas such as gene therapy and biocontrol.", }