According to the Codex Alimentarius, spices have been utilized since pre-historic times to enhance the flavor and taste of food. While this practice was most likely also applied to medicinal agents during these times, use of flavoring agents came to the forefront of medicine in the 19th century as pharmaceutical manufacturers added distinct flavors to patented products. Their use was to improve patient compliance by masking the unpleasant taste of drugs, a practice that continues today. It is also important to realize that flavor refers to more than simply what something tastes like. Flavor encompasses a substance?s taste, smell, and any physical traits we perceive in our mouth, such as heat (for example, cinnamon) or cold (for example, spearmint). During the recent push to identify the scientific mechanisms by which various spices and flavoring agents exert therapeutic effects that have been recorded for centuries, it has been found that stimulation of transient receptor potential channels (TRPs) contribute to the pharmacological profile of a variety of flavoring agents. Recent findings of expression patterns of TRP channels on antigen presenting cells, B and T cells and epithelial and sensory cells in the oral mucosa suggest that they may be logical targets for strengthening the immune response of vaccines given by the sublingual (SL) and buccal (BU) route through physical and biochemical means. The proposed studies intend to investigate the utility of flavoring agents, known to stimulate TRP channels, to strengthen the immune response to vaccine in a novel, dissolvable film when given by the SL and BU route. We will test the hypothesis that stepwise stimulation of TRPs located on epithelial cells in the oral mucosa, immune cells and distinct subsets of primary sensory neurons located in the oronasal cavity will significantly enhance the long-term immune response to a co-administered vaccine. This approach to adjuvant development is largely unexplored in the context of oral and other mucosal vaccines. We will first characterize the ability of each flavoring agent to stimulate pro-inflammatory responses necessary for recruitment of immune cells to the site of administration and enhance permeability across ex vivo and in vitro models of human oral mucosa. We will identify antigen presenting cells (APCs) recruited to the site of administration and in surrounding lymph nodes in response to each flavoring agent in several animal models. We will then assess systemic and localized T and B cell-mediated immune responses elicited after administration of flavored vaccines. Results from these studies will be extremely valuable, as they will identify novel targets for development of additional vaccine adjuvants. They will shed light on the type of immune response elicited by SL and BU immunization that will be valuable for the development of vaccination strategies against other pathogens and could resolve significant barriers to effective immunization including multiple dosing schedules, cold- chain requirements and the burden of needle-based platforms.
For the last 50 years, generations of parents around the globe have used the Mary Poppins lyric ?A spoonful of sugar makes the medicine go down? to help children take medicines. This project will look into the science behind natural flavoring agents like cinnamon and spearmint and determine if including them at certain concentrations in oral vaccines will improve their effectiveness. If successful, this work could profoundly impact the development of safe and effective needle-free vaccines for a variety of pathogens.
