A Rabies Virus Nucleocapsid-like Nanostructure Vaccine Based on Dual-Cationic Lipid Nanoparticles

Area of Science:

• Nanotechnology in vaccine development
• Virology and immunology
• Molecular biology and protein expression

Background:

• Rabies virus (RABV) causes significant annual human mortality, with current vaccines having limitations.
• Existing inactivated vaccines (INVs) exhibit restricted yield and immunogenicity.
• A new dual-cationic lipid nanoparticle (LNP)-based nucleocapsid-like nanostructure (NLS) was engineered.

Purpose of the Study:

• To develop and evaluate a novel dual-antigen NLS vaccine for rabies.
• To assess the immunogenicity and protective efficacy of the NLS vaccine.
• To investigate the engagement of MHC-I/II pathways by the NLS vaccine.

Main Methods:

• Engineered a dual-cationic LNP to co-encapsulate RABV G-mRNA and RABV-N protein.
• Characterized vaccine quality using encapsulation efficiency, DLS, PDI, zeta potential, and TEM.
• Assessed immunogenicity in mice via ELISA, RFFIT, ELISPOT, and qPCR, followed by viral challenge.

Main Results:

• The NLS vaccine achieved high encapsulation efficiency and optimal physicochemical properties.
• A single NLS dose rapidly induced neutralizing antibodies (nAb), with two doses peaking at ~1000 IU mL⁻¹.
• The NLS vaccine conferred 100% survival in mice, with robust cellular immunity and no viral rebound.

Conclusions:

• The dual-antigen NLS vaccine effectively activates MHC-I/II pathways, generating rapid, high-titer nAb and potent T-cell responses.
• A two-dose regimen of the NLS vaccine provided complete protection against rabies in a mouse model.
• The NLS platform represents a promising candidate for next-generation rabies vaccines.