Modified bacterial outer membrane vesicles induce autoantibodies for tumor therapy

Area of Science:

• Immunology
• Biotechnology
• Oncology

Background:

• Monoclonal antibodies targeting tumor angiogenesis are effective but limited by cost and treatment cycles.
• Novel strategies are needed for accessible and sustainable tumor immunotherapy.

Purpose of the Study:

• To develop a bacterial nanovaccine using outer membrane vesicles (OMVs) to induce autoantibodies against basic fibroblast growth factor (BFGF) for cancer therapy.
• To evaluate the efficacy of this nanovaccine in inhibiting tumor growth and its associated mechanisms.

Main Methods:

• Engineered bacterial outer membrane vesicles (OMVs) to carry the full-length BFGF protein.
• Immunized mice with the BFGF-loaded OMVs to induce anti-BFGF autoantibodies.
• Assessed tumor suppression functions including angiogenesis inhibition, apoptosis induction, immune barrier reversal, and cytotoxic T lymphocyte (CTL) activation.

Main Results:

• Induced persistent anti-BFGF autoantibodies in mice after only three immunizations.
• Demonstrated significant tumor suppression, including inhibited angiogenesis, induced apoptosis, and reversed immunosuppression.
• Observed enhanced tumor-specific cytotoxic T lymphocyte (CTL) responses, leading to tumor regression.

Conclusions:

• Bacterial biomembranes (OMVs) serve as effective vaccine delivery systems for inducing autoantibodies against tumor-associated antigens like BFGF.
• This nanovaccine approach offers a promising alternative to monoclonal antibodies for tumor immunotherapy, expanding applications of bacterial biomembrane systems.