Abstract

Engineered Synthetic Bacterial Vesicles as Cancer Immunotherapy and as Vaccines against Bacteria and SARS-CoV-2

Jan Lötvall, Professor/Chairman, University of Gothenburg

We are developing a novel platform of “exosome-like” synthetic bacterial vesicles (SyBV) that can be utilized as cancer immunotherapy, and as preventive vaccines against viral or bacterial infection. Briefly, the SyBV are produced from isolated bacterial membranes, and exhibit many of the features of natural bacterial veicles (OMV), but have been detoxified efficiently by removal of multiple bacterial components that activate pattern recognition receptors (PRR), including Toll Like Receptors (TLR). This strongly reduces the dose-limiting side effects of the SyBVs, but retains their stimulatory effects on adaptive immunity. The SyBV efficiently induce specific immunity via T-cell and humoral responses in both cancer models, and against bacterial components. SyBV combined with tumor exosomes induce immune responses in models of malignant melanoma and colon cancer, and synergize with checkpoint inhibitors to reduce or stop tumor growth. Further, SyBV can function as adjuvant in virus vaccine candidates, including SARS-CoV-2. SyBV is a safe and highly efficient platform with potentially very wide clinical applications in both cancer immunotherapy, as well as preventive vaccines against both bacterial and viral infections.