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Palur, V. R.

Publications and source records attributed to Palur, V. R..

2 recordsLinked to original sources

An Integrative Approach to Rational Engineering of Dengue Virus-Like Particles

Virus-like particles (VLPs) are promising vaccine candidates due to their noninfectious and highly immunogenic nature. These particles lack a viral genomic core and display a robust host immune response. VLPs are typically highly unstable and heterogeneous in size. This motivates the characterization of the biophysical and structural properties of VLPs to facilitate the rational design of stable and highly immunogenic particles. We employed an integrative approach combining multiscale modeling, lipidomics, and in vitro experiments to gain molecular insights into the factors governing VLP stability and homogeneity. We focused on dengue virus VLPs, which are known to elicit neutralizing antibodies similar to infectious virions. Systematic introduction of mutations in the structurally crucial stem helix region of the chimeric E protein guided by molecular simulations allowed us to modulate the secretion efficiency of VLPs in vitro. Overall, this work highlights the role of protein{square}lipid envelope interactions in maintaining VLP stability with better yield, providing a framework for the future development of stable and immunogenic next-generation VLP-based vaccines.

biophysics↗

Structural Insights into Immature Dengue Virus-Like Particles Revealed by Cryo-EM and Molecular Dynamics Simulations

The lack of efficacious vaccines against dengue (DENV) infections imposes an enormous burden on global health and the economy. Virus-like particles (VLPs), such as mature DENV VLPs (mDVLPs), have been shown to induce broadly neutralizing antibodies, making them promising next-generation vaccine candidates. However, the limited structural details have restricted efforts to engineer VLPs to attain the desired biophysical and immunological properties. In the current work, we present the cryo-electron microscopy (cryo-EM) structure of immature dengue serotype 2 VLP (imD2VLPs), revealing an architecture composed of a glycoprotein layer with prominent spikes in a T=1 arrangement. These spikes, composed of envelope (E) and precursor membrane (prM) protein heterodimers capped by pr domains, closely resemble immature flavivirus particles. Complementing the static structural details, we performed multiscale molecular dynamics (MD) simulations to elucidate the functional dynamics of imD2VLPs in the context of different lipid envelope compositions. Additionally, MD simulations uncovered the transition pathway between our previously solved mature VLP structure and immature VLP from this work. Here we show that VLP maturation involves a simple sliding-rotating motion without any clashes between E proteins. Our results also indicated that lipid composition plays a critical role in VLP stability, with phospholipid-dominant environments providing greater stability than diacylglycerol-rich vesicles. In addition, we demonstrated enhanced production efficiency of VLPs by generating a stable mammalian cell line using CHO-K1 cells. These findings enabled us not only to predict and manipulate the immunogenic properties of dengue VLPs but also underscored the potential of VLPs as a simplified and manageable model for investigating the structural basis of the dengue virus more effectively.

bioinformatics↗