Engineered Attenuated Salmonella typhimurium Expressing Neoantigen Has Anticancer Effects

Area of Science:

• Oncology
• Immunotherapy
• Microbial Engineering

Background:

• Neoantigen vaccines are a promising cancer immunotherapy.
• Current strategies face challenges with rapid vaccine degradation and precise immune cell targeting.
• Developing effective delivery systems is crucial for neoantigen vaccine efficacy.

Purpose of the Study:

• To engineer attenuated Salmonella typhimurium as a tumor-infiltrating carrier for neoantigen peptide vaccines.
• To evaluate the efficacy of this engineered Salmonella-based delivery system in vivo.

Main Methods:

• Attenuated Salmonella typhimurium was genetically modified to express neoantigen peptides using a constitutive promoter.
• In vivo experiments were conducted using bacteria-treated mice bearing tumors.
• Tumor growth, survival rates, T cell populations (CD4 and CD8), and cytokine release were assessed.

Main Results:

• Engineered Salmonella successfully infiltrated tumors and expressed neoantigens.
• Significant suppression of tumor growth was observed in treated mice.
• Higher survival rates, longer survival times, increased CD4/CD8 T cell counts, and elevated cytokine release were documented.

Conclusions:

• Engineered Salmonella typhimurium serves as an effective carrier for neoantigen immunotherapy.
• This approach offers a stable and targeted delivery method for cancer vaccines.
• The system demonstrates potential for improving anti-tumor immunity and patient outcomes.