Purification and immunogenicity of Nipah virus-like particles from insect cells

Nipah virus (NiV) is an emerging high-fatality zoonotic threat lacking approved vaccines. Current virus-like particle (VLP) production methods rely on costly mammalian cell systems and non-scalable ultracentrifugation purification. We developed an alternative enveloped Nipah virus-like particle (NiVLP) expression system in Sf9 insect cells by co-expressing structural proteins F, G, and M using a single recombinant baculovirus. A novel multi-step chromatographic purification process was established using monolith convective media, integrating steric exclusion chromatography with sequential cation and anion exchange steps. Purified NiVLPs were characterized by nanoparticle tracking analysis and transmission electron microscopy, followed by immunogenicity study in Syrian golden hamsters. The optimized process yielded enveloped particles of approximately 100–120 nm that morphologically resemble native NiV virions. A single 25 µg NiVLP dose induced robust systemic anti-NiV G IgG responses within 14 days, demonstrating rapid immunogenicity suitable for outbreak response. However, neutralizing antibody titers against NiV remained limited compared to total IgG responses. This study establishes the first chromatography-based manufacturing platform for morphologically correct NiVLPs from insect cells. A deeper understanding of the immunity generated is needed to support their potential as a rapidly deployable vaccine platform against NiV.