Search bioRxiv⌕ Search

Biology subjects

Bezeljak, U.

Publications and source records attributed to Bezeljak, U..

2 recordsLinked to original sources

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 efficient production system for enveloped NiVLPs by co-expressing structural proteins F, G, and M using a baculovirus expression vector system in Sf9 cells. 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, then evaluated for immunogenicity in Syrian golden hamsters. The optimized process yielded enveloped particles of approximately 100-120 nm that morphologically resemble native NiV virions. A single 25 g 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.

bioengineering↗

Stochastic activation and bistability in a Rab GTPase regulatory network.

Rab GTPases are the central regulators of intracellular traffic. Their function relies on a conformational change triggered by nucleotide exchange and hydrolysis. While this switch is well understood for an individual protein, how Rab GTPases collectively transition between states to generate a biochemical signal in space and time is unclear. Here, we combine in vitro reconstitution experiments with theoretical modeling to study a minimal Rab5 activation network. We find that positive feedback in this network gives rise to bistable switching of Rab5 activation and provide evidence that controlling the inactive population of Rab5 on the membrane can shape the network response. Together, our findings reveal new insights into the non-equilibrium properties and general principles of biochemical signaling networks underlying the spatiotemporal organization of the cell.

systems biology↗