Zika Virus Baculovirus-Expressed Virus-Like Particles Induce Neutralizing Antibodies in Mice

Abstract

The newly emerged mosquito-borne Zika virus (ZIKV) strains pose a global challenge owing to its ability to cause microcephaly and neurological disorders. Several ZIKV vaccine candidates have been proposed, including inactivated and live attenuated virus vaccines, vector-based vaccines, DNA and RNA vaccines. These have been shown to be efficacious in preclinical studies in mice and nonhuman primates, but their use will potentially be a threat to immunocompromised individuals and pregnant women. Virus-like particles (VLPs) are empty particles composed merely of viral proteins, which can serve as a safe and valuable tool for clinical prevention and treatment strategies. In this study, we used a new strategy to produce ZIKV VLPs based on the baculovirus expression system and demonstrated the feasibility of their use as a vaccine candidate. The pre-membrane (prM) and envelope (E) proteins were co-expressed in insect cells and self-assembled into particles similar to ZIKV. We found that the ZIKV VLPs could be quickly and easily prepared in large quantities using this system. The VLPs were shown to have good immunogenicity in immunized mice, as they stimulated high levels of virus neutralizing antibody titers, ZIKV-specific IgG titers and potent memory T cell responses. Thus, the baculovirus-based ZIKV VLP vaccine is a safe, effective and economical vaccine candidate for use against ZIKV.

The Capsid Protein of Semliki Forest Virus Antagonizes RNA Interference in Mammalian Cells

“…For the TEM, virions were adsorbed to glow-discharged electron microscope grids and negatively stained with purified terephthalic acid according to our standard procedures (50). Samples were imaged by using a 100-kV Hitachi H-7000FA transmission electron microscope.…”

Mosquito Cell-Derived Japanese Encephalitis Virus-Like Particles Induce Specific Humoral and Cellular Immune Responses in Mice

“…Mosquito cell-derived JEV VLPs presented a density range of~35-45% sucrose ( Figure 4A). TEM and DLS analysis revealed that the average diameter of the JEV VLPs was roughly 30 nm ( Figure 4C), which is similar to the size of Zika [56] and JE GV VLPs [23,29] produced using a conventional baculovirus system or stable cell lines.…”

The 3A protein of coxsackievirus B3 acts as a viral suppressor of RNA interference

“…The expression and purification of proteins from an Escherichia coli system were performed as described previously [33, 34]. Briefly, recombinant protein MBP-3A and the negative control protein, MBP, were expressed in E.…”