Natural and synthetic saponin adjuvant QS-21 for vaccines against cancer

Abstract

One of the most widely used and potent immunological adjuvants is a mixture of soluble triterpene glycosides purified from the soap bark tree (Quillaja saponaria). Despite challenges in production, quality control, stability and toxicity, the QS-21 fraction from this extract has exhibited exceptional adjuvant properties for a range of antigens. It possesses an ability to augment clinically significant antibody and T-cell responses to vaccine antigens against a variety of infectious diseases, degenerative disorders and cancers. The recent synthesis of active molecules of QS-21 has provided a robust method to produce this leading vaccine adjuvant in high purity as well as to produce novel synthetic QS-21 congeners designed to induce increased immune responsiveness and decreased toxicity.

Keywords::

• adjuvants
• saponins
• synthetic adjuvants
• vaccines

Dedication

This work is dedicated to the memory of our deceased friend and colleague, David Y Gin.

Financial & competing interests disclosure

Supported by grants from the NIH (R01 GM058833 and AI085622); William H Goodwin and Alice Goodwin; the Commonwealth Foundation for Cancer Research; and The Experimental Therapeutics Center of Memorial Sloan-Kettering Cancer Center. The authors would like to disclose stock ownership in Adjuvance Technologies, Inc., which has licensed the synthetic approaches to saponin preparation from Memorial Sloan-Kettering Cancer Center (MSKCC). Philip Livingston and Govind Ragupathi are also paid consultants to, and shareholders in, MabVax Therapeutics Inc., which has licensed the KLH-conjugate vaccines from MSKCC. These stock ownerships have been fully disclosed to our institution through a conflict of interest disclosure and a conflict of interest management plan has been implemented with MSKCC. 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.