Cationic liposomes as vaccine adjuvants

Abstract

The application of cationic liposomes as vaccine delivery systems and adjuvants has been investigated extensively over the last few decades. However, cationic liposomes are, in general, not sufficiently immunostimulatory, which is why the combination of liposomes with immunostimulating ligands has arisen as a strategy in the development of novel adjuvant systems. Within the last 5 years, two novel adjuvant systems based on cationic liposomes incorporating Toll-like receptor or non-Toll-like receptor immunostimulating ligands have progressed from preclinical testing in smaller animal species to clinical testing in humans. The immune responses that these clinical candidates induce are primarily of the Th1 type for which there is a profound unmet need. Furthermore, a number of new cationic liposome-forming surfactants with notable immunostimulatory properties have been discovered. In this article we review the recent progress on the application of cationic liposomes as vaccine delivery systems/adjuvants.

Keywords::

• adjuvant
• cationic liposome
• DC-Chol
• DDA
• delivery system
• DiC14-amidine
• DOTAP
• DOTIM
• immunostimulator
• vaccine

Acknowledgements

The authors would like to thank their colleagues in the Department of Infectious Disease Immunology (Statens Serum Institut, Copenhagen, Denmark) for contributing to the ideas contained in this article.

Financial & competing interests disclosure

The authors are coinventors of patents relating to cationic liposomes as vaccine adjuvants. All rights have been assigned to the Statens Serum Institut (Copenhagen, Denmark). All authors are employees at Statens Serum Institut. 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 materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.