A Bacterial-Based Immunotherapy for PDAC

Area of Science:

• Oncolytic immunotherapy
• Bacterial cancer therapy
• Tumor immunology

Background:

• Pancreatic ductal adenocarcinoma (PDAC) remains a challenging cancer with limited treatment options.
• Effective anti-tumor immune responses are crucial for successful cancer therapy.
• Developing novel delivery systems for cancer antigens is essential for immunotherapy.

Purpose of the Study:

• To investigate the potential of engineered Listeria monocytogenes as a delivery vehicle for tetanus toxoid.
• To evaluate the efficacy of tetanus toxoid-pulsed Listeria monocytogenes in reactivating anti-tumor T cell memory.
• To assess the anti-tumor activity against pancreatic ductal adenocarcinoma in a preclinical mouse model.

Main Methods:

• Listeria monocytogenes was engineered to express and deliver tetanus toxoid.
• Mice with pancreatic ductal adenocarcinoma were vaccinated with tetanus toxoid.
• The reactivation of tetanus-specific memory T cells and their tumor-infiltrating capacity were analyzed.
• Tumor growth and survival were monitored in response to the treatment.

Main Results:

• Engineered Listeria monocytogenes successfully delivered tetanus toxoid to the tumor microenvironment.
• Pre-existing tetanus-specific memory T cells were reactivated and migrated to the tumor site.
• Reactivated T cells demonstrated tumor-destructive capabilities, leading to reduced tumor burden.
• Significant anti-tumor efficacy was observed in treated mice.

Conclusions:

• Bacterial delivery of tetanus toxoid can effectively reawaken anti-tumor T cell immunity.
• This approach shows promise as a novel immunotherapy strategy for pancreatic cancer.
• Further clinical evaluation in a phase I trial is planned to assess safety and efficacy in human patients.