Shaping Modern Vaccines: Adjuvant Systems Using MicroCrystalline Tyrosine (MCT®)
Matthew D. Heath, Mona O. Mohsen, Pieter‐Jan de Kam, Thalia L. Carreno Velazquez, Simon Hewings, Matthias Krämer, Thomas M. Kündig, Martin F. Bachmann, Murray Skinner
Abstract
The concept of adjuvants or adjuvant systems, used in vaccines, exploit evolutionary relationships associated with how the immune system may initially respond to a foreign antigen or pathogen, thus mimicking natural exposure. This is particularly relevant during the non-specific innate stage of the immune response; as such, the quality of this response may dictate specific adaptive responses and conferred memory/protection to that specific antigen or pathogen. Therefore, adjuvants may optimise this response in the most appropriate way for a specific disease. The most commonly used traditional adjuvants are aluminium salts; however, a biodegradable adjuvant, MCT ® , was developed for application in the niche area of allergy immunotherapy (AIT), also in combination with a TLR-4 adjuvant—Monophosphoryl Lipid A (MPL ® )—producing the first adjuvant system approach for AIT in the clinic. In the last decade, the use and effectiveness of MCT ® across a variety of disease models in the preclinical setting highlight it as a promising platform for adjuvant systems, to help overcome the challenges of modern vaccines. A consequence of bringing together, for the first time, a unified view of MCT ® mode-of-action from multiple experiments and adjuvant systems will help facilitate future rational design of vaccines while shaping their success.