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 β-D-glucan and showed particle sizes and zeta potentials approximately 128.8 nm and -7.39 mV, respectively. S-EVs were positive for heat shock protein 70 kDa (HSP70). These S-EVs considerably enhanced the production of proinflammatory tumor necrosis factor-α and interleukin 6 from RAW264.7 cells (mouse macrophage-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 cerevisiae are an attractive source as a novel vaccine material for immune cells maturation.

Higuchi A ，Morishita M ，Nagata R ，Maruoka K ，Katsumi H ，Yamamoto A ... -  《-》

Lymphatic Transport and Immune Activation Effect by Locally Administered Extracellular Vesicles from Saccharomyces cerevisiae as Biocompatible Vaccine Adjuvants.

Morishita M ，Nagata R ，Maruoka K ，Higuchi A ，Sasaki S ，Wada S ，Katsumi H ，Yamamoto A ... -  《-》

Characterizing Different Probiotic-Derived Extracellular Vesicles as a Novel Adjuvant for Immunotherapy.

Morishita M ，Horita M ，Higuchi A ，Marui M ，Katsumi H ，Yamamoto A ... -  《-》

Activation of Host Immune Cells by Probiotic-Derived Extracellular Vesicles via TLR2-Mediated Signaling Pathways.

Morishita M ，Sagayama R ，Yamawaki Y ，Yamaguchi M ，Katsumi H ，Yamamoto A ... -  《-》

The linear structure of β-glucan from baker's yeast and its activation of macrophage-like RAW264.7 cells.

Yeast β-glucan has many formulations with different chemical structures, water solubility and purity. In particular, the purity of β-glucan in these formulations is variable and relatively low, contributing to different data on its biological activity. In this study, the major polysaccharide component in the crude Baker's yeast polysaccharides coded as BBG with high purity of 99% was obtained, and its chemical structure was determined to be a linear β-(1,3)-glucan. It was found that BBG interacted with complement receptor 3 (CR3) and toll-like receptor 2 (TLR2) on the surface of macrophage-like RAW264.7 cells, and initiated activation of RAW264.7 cells characterized by significant production of tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1). Additionally, activation of the nuclear factor kappaB p65 (NF-κB p65), c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) induced by BBG, were also observed, further confirming the stimulation of RAW264.7 cells by BBG. All these findings provided important scientific evidences for better understanding the molecular mechanism of action for the linear β-(1,3)-glucan in cells.

Zheng X ，Zou S ，Xu H ，Liu Q ，Song J ，Xu M ，Xu X ，Zhang L ... -  《-》