An engineered HIV-1 Gag-based VLP displaying high antigen density induces strong antibody-dependent functional immune...

Area of Science:

• Immunology
• Virology
• Vaccine Development

Background:

• Virus-Like Particles (VLPs) enhance antigen immunogenicity over soluble proteins.
• Increasing antigen density on VLPs is a strategy to further boost immune responses.

Purpose of the Study:

• To engineer an HIV-1 Gag-based VLP platform to maximize surface antigen presentation.
• To evaluate the immunogenicity and functional effects of these high-density VLPs.

Main Methods:

• Fusion of an HIV-1 gp41-derived protein (Min) to HIV-1 Gag to create high-density MinGag-VLPs.
• Immunization of animal models with MinGag-VLPs using homologous and heterologous prime-boost regimens.
• Assessment of humoral responses, antibody profiles, and in vivo anti-tumor activity.

Main Results:

• High-density MinGag-VLPs were successfully generated and demonstrated high immunogenicity.
• Heterologous DNA/VLP vaccination yielded 10-fold higher antibody titers compared to homologous VLP vaccination.
• Vaccination induced IgG2b/IgG2c antibodies binding CD16-2 and halted tumor progression, but did not induce neutralizing antibodies.

Conclusions:

• High-density antigen display on VLPs significantly enhances humoral immune responses.
• MinGag-VLP vaccination provides a functional anti-tumor effect in a preclinical model.
• Further optimization may be needed to elicit neutralizing antibodies for potential therapeutic applications.