Engineering a streamlined virus-like particle for programmable tissue-specific gene delivery.

Area of Science:

• Biomedical Engineering
• Molecular Virology
• Gene Therapy

Background:

• Virus-like particles (VLPs) are promising transient gene delivery vehicles.
• Limited tropisms of current VLPs restrict their therapeutic applications.
• Engineering retrovirus-based VLPs is challenging due to complex viral proteins.

Purpose of the Study:

• To develop a streamlined and programmable VLP vector system.
• To overcome engineering challenges associated with retrovirus-based VLPs.
• To create VLPs with customizable tropisms for enhanced gene delivery.

Main Methods:

• Customized a Semliki Forest Virus (SFV) backbone for VLP vector construction.
• Engineered the envelope protein (Env) via peptide insertion or pseudotyping.
• Tested VLP cargo capacity for mRNA (500 bp to 10 kb), protein, and ribonucleoprotein (RNP).

Main Results:

• Generated VLP candidates with enhanced in vivo blood-brain barrier (BBB) penetration.
• Achieved expanded in vitro targeting ranges and escape from neutralizing antibodies (Nab).
• Demonstrated muscle-targeting capabilities with engineered VLPs.

Conclusions:

• The developed SFV-based VLP system offers a programmable platform for gene delivery.
• Customizable tropisms enable tailored VLP vectors for diverse therapeutic strategies.
• This approach minimizes virus-derived components for safer gene delivery.