Yeasts as a promising delivery platform for DNA and RNA vaccines.

Yeasts are considered a useful system for the development of vaccines for human and veterinary health. Species such as Saccharomyces cerevisiae and Pichia pastoris have been used successfully as host organisms for the production of subunit vaccine antigens. In the last two decades, these organisms have been also explored as vaccine vehicles enabling the delivery of antigens such as proteins and nucleic acids. The employed species of yeasts possess a GRAS status (Generally Recognized as Safe) for the production of therapeutic proteins, besides promoting immunostimulation due to the properties of their wall cell composition. This strategy allows the administration of nucleic acids orally and a specific delivery to professional antigen-presenting cells (APCs). In this review, we seek to outline the development of whole yeast vaccines (WYV) strategies as carriers of nucleic acids in different approaches in the medical field, as well as the immunological aspects of this vaccine strategy. The data presented here reveal the application of this platform in promoting effective immune responses in the context of prophylactic and therapeutic approaches against infectious diseases, in addition to the possible use in immunotherapies for different types of cancer.