Virus glycoprotein nanodisc platform for vaccine analytics.

Area of Science:

• Virology
• Immunology
• Biochemistry
• Nanotechnology

Background:

• Transmembrane glycoproteins on enveloped viruses are key targets for neutralizing antibodies and crucial vaccine antigens.
• Current methods for studying these antigens and post-vaccination antibody responses often rely on soluble protein forms, limiting comprehensive analysis.
• Messenger RNA-lipid nanoparticle (mRNA-LNP) technology enables in vivo expression but requires robust in vitro characterization tools.

Purpose of the Study:

• To present a novel platform for assembling viral transmembrane glycoprotein vaccine candidates into lipid nanodiscs.
• To demonstrate the utility of these nanodiscs for biophysical characterization and structure-based immunogen design.
• To showcase the platform's applicability for developing vaccines against viruses like HIV and Ebola.

Main Methods:

• Assembling transmembrane glycoproteins into lipid nanodiscs.
• Utilizing surface plasmon resonance (SPR) for binding assays.
• Employing fluorescence-activated cell sorting (FACS) for ex vivo B cell sorting.
• Determining the structure of nanodisc-immunogen complexes using cryogenic electron microscopy (cryo-EM).

Main Results:

• Demonstrated the utility of nanodiscs in HIV membrane proximal external region (MPER)-targeting vaccine development.
• Determined the high-resolution cryo-EM structure of an MPER-targeting immunogen nanodisc complexed with broadly neutralizing antibodies (bnAbs).
• Characterized Ebola virus glycoprotein nanodiscs, demonstrating the platform's general applicability.

Conclusions:

• The lipid nanodisc platform facilitates the biophysical characterization of viral transmembrane glycoproteins.
• This platform provides a template for structure-based immunogen design, particularly for challenging targets like the HIV MPER.
• The developed platform accelerates the development of next-generation vaccines by enabling better antigen presentation and characterization.