Streptococcus pneumoniae-derived Exosome Research and Application

The development and study of the Streptococcus pneumoniae-derived exosome has facilitated an in-depth understanding of the mechanisms of infection and transmission of pathogens and has also opened up new possibilities for the development of safe and effective cell-free vaccine strategies. Creative Biolabs specializes in advancing the understanding of the Streptococcus pneumoniae-derived exosome by providing a comprehensive range of research services from isolation to analysis.

Isolation of Streptococcus pneumoniae-derived Exosome

Culture Streptococcus pneumoniae overnight at 37°C and then collect the bacterial medium.
Centrifuge Streptococcus pneumoniae cultures at low speed to remove bacterial bodies and debris.
Aseptically filter the Streptococcus pneumoniae supernatant and confirm the sterility of the supernatant by overnight incubation.
Ultracentrifuge the sterile supernatant to obtain exosome precipitates.
Resuspend the Streptococcus pneumoniae-derived exosomes with PBS.
Further purify Streptococcus pneumoniae-derived exosome from soluble protein impurities using SEC columns loaded with agarose.

Research on Streptococcus pneumoniae-derived Exosome

Research	Conclusion
Characterization of vesicles isolated from Streptococcus pneumoniae.	Cryo-transmission electron microscopy observations revealed that vesicles from Streptococcus pneumoniae display heterogeneity in morphology, size, and content, identified to a variety of structures and particle diameters including spherical, rod-shaped, chain-like arrangements and irregularities. In addition, there may be different shades of color depending on the content.
Cytotoxicity of Streptococcus pneumoniae-derived exosome.	Cell viability assays revealed that the human lung epithelial cell line, human keratinocyte-forming cell line, differentiated human macrophage phenotype, and mouse dendritic cell line exhibited tolerance to Streptococcus pneumoniae-derived exosome without any toxic effects.
Cellular Uptake of Streptococcus pneumoniae-derived exosome.	Flow cytometry and fluorescent tracer exosome assays revealed that Streptococcus pneumoniae-derived exosome could be taken up by human lung epithelial cell lines, human keratinocyte-forming cell lines, differentiated human macrophage phenotypes, and mouse dendritic cell lines for the delivery of bacterial-associated cargoes, and the extent of uptake was better in immune cells.

Fig. 1 Streptococcus pneumoniae-derived exosomes are taken up by cells in a time-dependent manner.¹

Research	Conclusion
The immunostimulatory potential of Streptococcus pneumoniae-derived exosome.	ELISA of dendritic cells after incubation with exosomes revealed that Streptococcus pneumoniae-derived exosomes were able to stimulate the release of inflammation-associated factors, showing potential to stimulate immunity. Streptococcus pneumoniae-derived exosomes were able to activate NF-κB signaling in macrophages in a dose-dependent manner.
Biological functions of immunity induced by Streptococcus pneumoniae-derived exosomes and their mechanisms.	Examination of PBMC cells and spleens from mice injected intravenously with exosomes revealed that Streptococcus pneumoniae-derived exosome induced a significant increase in M2 macrophages and immune responses. The contribution of bacterial lipoproteins to the activation of NF-κB and regulation of host immune signaling by the Streptococcus pneumoniae-derived exosome was shown by comparison with exosomes derived from the same strain with gene deletion mutations.
Streptococcus pneumoniae-derived exosomes regulation of adaptive immunity.	Analysis of the Streptococcus pneumoniae-derived exosome-treated mouse models revealed that topical inoculation with Streptococcus pneumoniae-derived exosome triggered the recruitment of host immune cells in the microenvironment and immune responses. In addition, Streptococcus pneumoniae-derived exosome induced the activation of M2-type macrophages thereby favoring the chronic carriage of bacteria.

Fig. 2 Streptococcus pneumoniae-derived exosomes induced host cell recruitment.²

Recently there has been a growing understanding of exosome-like vesicles isolated from Gram-positive bacteria including Streptococcus pneumoniae. Creative Biolabs can provide efficient and reliable services for the study of Streptococcus pneumoniae-derived exosomes, contributing to the exploration of bacterial vesicles as vaccine candidates. Please contact us with interest.

References

Mehanny, Mina, et al. "Streptococcal extracellular membrane vesicles are rapidly internalized by immune cells and alter their cytokine release." Frontiers in immunology 11 (2020): 80.
Yerneni, Saigopalakrishna S., et al. "Pneumococcal extracellular vesicles modulate host immunity." MBio 12.4 (2021): 10-1128.

Plant Exosome Isolation