Vaccine approaches for antigen capture by liposomes

ABSTRACT

Introduction

Liposomes have been used as carriers for vaccine adjuvants and antigens due to their inherent biocompatibility and versatility as delivery vehicles. Two vial admixture of protein antigens with liposome-formulated immunostimulatory adjuvants has become a broadly used clinical vaccine preparation approach. Compared to freely soluble antigens, liposome-associated forms can enhance antigen delivery to antigen-presenting cells and co-deliver antigens with adjuvants, leading to improved vaccine efficacy.

Areas covered

Several antigen-capture strategies for liposomal vaccines have been developed for proteins, peptides, and nucleic acids. Specific antigen delivery methodologies are discussed, including electrostatic adsorption, encapsulation inside the liposome aqueous core, and covalent and non-covalent antigen capture.

Expert opinion

Several commercial vaccines include active lipid components, highlighting an increasingly prominent role of liposomes and lipid nanoparticles in vaccine development. Utilizing liposomes to associate antigens offers potential advantages, including antigen and adjuvant dose-sparing, co-delivery of antigen and adjuvant to immune cells, and enhanced immunogenicity. Antigen capture by liposomes has demonstrated feasibility in clinical testing. New antigen-capture techniques have been developed and appear to be of interest for vaccine development.

KEYWORDS:

• Liposomes
• phospholipids
• bilayer
• antigen
• adjuvant
• QS-21
• Monophosphoryl lipid a
• lipopeptides

Article highlights

• Liposomes are broadly used as versatile vaccine adjuvant carriers

• Coupling antigens with liposomes can enhance immunogenicity

• Many liposomal approaches for antigen capture have been developed, some progressing to clinical testing

Declaration of interests

J.F Lovell holds an interest in POP Biotechnologies. Other authors declare no relevant competing interests. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or material discussed in the manuscript apart from those disclosed.

Reviewer disclosures

A reviewer on this manuscript is a current employee at GlaxoSmithKline. Peer reviewers on this manuscript have no other relevant financial or other relationships to disclose.

Author contributions

All authors contributed to the conception and design of the review article and interpretation of the relevant literature and were involved in writing the review article or revising it for intellectual content.

Additional information

Funding

This manuscript was funded by the National Institutes of Health (R01CA247771, R0AI148557, and R61AI169199) and the Department of Defense (W81XWH-22-1-0562).