Enhancing the Effect of Nucleic Acid Vaccines in the Treatment of HPV-Related Cancers: An Overview of Delivery Systems

Abstract

Prophylactic vaccines against human papillomavirus (HPV) have proven efficacy in those who have not been infected by the virus. However, they do not benefit patients with established tumors. Therefore, the development of therapeutic options for HPV-related malignancies is critical. Third-generation vaccines based on nucleic acids are fast and simple approaches to eliciting adaptive immune responses. However, techniques to boost immunogenicity, reduce degradation, and facilitate their capture by immune cells are frequently required. One option to overcome this constraint is to employ delivery systems that allow selective antigen absorption and help modulate the immune response. This review aimed to discuss the influence of these different systems on the response generated by nucleic acid vaccines. The results indicate that delivery systems based on lipids, polymers, and microorganisms such as yeasts can be used to ensure the stability and transport of nucleic acid vaccines to their respective protein synthesis compartments. Thus, in view of the limitations of nucleic acid-based vaccines, it is important to consider the type of delivery system to be used—due to its impact on the immune response and desired final effect.

RNA Vaccines: Yeast as a Novel Antigen Vehicle

“…Despite the preferential study by delivery particles of lipid and polymeric origin, new approaches involving natural delivery systems based on microorganisms emerge as novel systems to be explored [20, 22 -23]. Due to their composition, they can signalize efficient immune responses, promoting a specific uptake, transporting nucleic acids anchored superficially or in their interior, and expanding the range of administration methods [8]. Among microorganisms, yeasts have application value as biofactories of therapeutic proteins and carriers of biological molecules [8][9].…”

“…Due to their composition, they can signalize efficient immune responses, promoting a specific uptake, transporting nucleic acids anchored superficially or in their interior, and expanding the range of administration methods [8]. Among microorganisms, yeasts have application value as biofactories of therapeutic proteins and carriers of biological molecules [8][9]. However, despite its potential, there is still a need for a better understanding of its applicability in the delivery of mRNA vaccines, as well as a better evaluation of the mechanisms of uptake and transport.…”

“…Several methods have already been adopted, such as lipid nanoparticles used in mRNA vaccines developed for SARS-CoV-2 [6,7]. However, the application of microorganisms as delivery systems has been gaining prominence due to their ability to generate efficient immune responses, specific capture, and physical protection for the vaccine antigen [8]. In this context, yeasts such as Saccharomyces Disclaimer/Publisher's Note: The statements, opinions, and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s).…”