Functional Characterization of Extracellular Vesicles from Baker's Yeast Saccharomyces Cerevisiae as a Novel Vaccine Material for Immune Cell Maturation

Extracellular vesicles (EVs) encapsulate various bioactive molecules, and much effort has been directed towards developing a novel EV-based therapy. Although recent studies reported the secretion of EVs from probiotics baker's yeast Saccharomyces cerevisiae (S. cerevisiae), their properties and functions remain obscure. The aim of this study was to clarify the usefulness of EVs from S. cerevisiae (S-EVs) as a novel vaccine material by defining their physicochemical properties and biological functions. The collected S-EVs contained /3-D-glucan and showed particle sizes and zeta potentials approximately 128.8 nm and-7.39 mV, respec-tively. S-EVs were positive for heat shock protein 70 kDa (HSP70). These S-EVs considerably enhanced the production of proinflammatory tumor necrosis factor -a and interleukin 6 from RAW264.7 cells (mouse mac-rophage-like cells) and DC2.4 cells (mouse dendritic cells). The expression of maturation markers CD40, CD80 and CD86 on the surface of these immune cells incubated with S-EVs was remarkably upregulated. Immune cells endocytosed S-EVs, and toll like receptor 2 on immune cells was involved in immune activation by S-EVs. These results indicate that extracellular vesicles derived from baker's yeast Saccharomyces cerevi-siae are an attractive source as a novel vaccine material for immune cells maturation.(c) 2022 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.

Automated summary

This study aimed to clarify the usefulness of extracellular vesicles (EVs) secreted by baker's yeast Saccharomyces cerevisiae as a novel vaccine material. The collected EVs contained 3-D-glucan and exhibited particle sizes and zeta potentials of approximately 128.8 nm and -7.39 mV, respectively. They significantly enhanced the production of proinflammatory cytokines and promoted the maturation and activation of immune cells. Therefore, EVs derived from baker's yeast are an attractive source for novel vaccine materials.