Bacterial outer membrane vesicles suppress tumor by interferon-γ-mediated antitumor response

Area of Science:

• Immunology
• Nanotechnology
• Oncology

Background:

• Gram-negative bacteria produce outer membrane vesicles (OMVs), which are nanoscale proteolipids.
• OMVs are recognized for their potential as vaccines and drug delivery systems.
• The therapeutic application of OMVs in cancer treatment remains unexplored.

Purpose of the Study:

• To investigate the potential of bacterial outer membrane vesicles (OMVs) as immunotherapeutic agents for cancer treatment.
• To evaluate the efficacy of OMVs in eradicating established tumors and preventing metastasis.
• To elucidate the mechanisms underlying OMV-mediated antitumor immune responses.

Main Methods:

• Systematic administration of bacterial OMVs in a tumor model.
• Assessment of tumor eradication and metastasis prevention.
• Analysis of immune cell infiltration and cytokine production (CXCL10, interferon-γ) in tumor tissues.
• Evaluation of OMV efficacy in interferon-γ-deficient mice.

Main Results:

• Bacterial OMVs effectively eradicated established tumors and prevented metastasis.
• OMVs specifically targeted and accumulated in tumor tissues.
• OMVs induced significant production of antitumor cytokines CXCL10 and interferon-γ.
• The antitumor effects were dependent on interferon-γ, as demonstrated in deficient mice.
• No notable adverse effects were observed with OMV administration.

Conclusions:

• Bacterial outer membrane vesicles (OMVs) demonstrate significant potential as a novel immunotherapeutic agent for cancer treatment.
• OMVs can induce long-term antitumor immune responses, leading to tumor eradication and prevention of metastasis.
• The efficacy of OMVs is mediated by interferon-γ-dependent mechanisms, highlighting their role in modulating the tumor microenvironment.