Modified Bacterial Outer Membrane Vesicles Induce Autoantibodies for Tumor Therapy

Using monoclonal antibodies to block tumor angiogenesis has obtained effective anti-tumor effects. However, this treatment method has long cycles and is very expensive; therefore, its long-term and extensive application is limited. In this study, we developed a nanovaccine using bacterial biomembrane as carriers for anti-tumor therapy. The whole basic fibroblast growth factor (BFGF) molecule (154 aa) was loaded onto bacterial outer membrane vesicles (OMVs) using gene recombination technology. The strong adjuvant effect of OMVs was used to induce the host to produce anti-BFGF autoantibodies. We proved that persistent anti-BFGF autoantibodies could be induced in mice after only 3 immunizations to antagonize BFGF functions. The presentations were multiple tumor suppression functions including inhibition of tumor angiogenesis, induction of tumor cell apoptosis, reversal of tumor immune barriers, and promotion of tumor-specific cytotoxic T lymphocytes (CTLs), eventually causing tumor regression. We, for the first time, confirmed that bacterial biomembrane could be used as a vaccine delivery system to induce the production of antibodies against autoantigens, which could be used for tumor therapy. This study expands the application fields of bacterial biomembrane systems and provides new thinking for tumor immunotherapy other than monoclonal antibody technology.