[WS1-4] Bacterial Membrane Vesicles: Towards vaccine applications based on the versatile functions
Bacteria release spherical proteoliposomes called bacterial membrane vesicles (BMVs) under favorable and unfavorable growth conditions, which range in size from 10 to 300 nm in diameter. Our research group is now pursuing “sustainable intranasal vaccine platform” using BMVs. In this presentation, I will talk about my first encounter with BMVs, followed by inspiration from the “fascinating physicochemical and biological properties”. Then, the following two research projects towards to vaccine development using BMVs will be introduced. The one is vaccine development against periodontitis, a very common disease in adults, by means of intranasal administration with BMVs of Porphyromonas gingivalis and the other periodontopathic bacteria. The other topic is our recent efforts to establish general vaccine platform by using bioengineered BMVs from probiotic bacteria that can highly express exogenous capsular polysaccharides. A straightforward example of chimeric BMVs of probiotic Escherichia coli expressing pneumococcal capsule will be provided with clear-cut results showing the mucosal adjuvanticity/immunogenicity, as well as the inhibitory effect on nasopharyngeal carriage of pneumococcus in a mouse model. In addition, the safety issues to be carefully addressed will be also discussed with the future practical use in mind.