Prospects and progress of Listeria-based cancer vaccines

ABSTRACT

Introduction: The development of an effective therapeutic vaccine to induce cancer-specific immunity remains problematic. Recently, a species of intracellular pathogen known as Listeria monocytogenes (Lm) has been used to transfer DNA, RNA and proteins into tumour cells as well as elicit an immune response against tumour-specific antigens.

Areas covered: Herein, the authors provide the mechanisms of different Listeria monocytogenes strains, which are potential therapeutic cancer vaccine vectors, in addition to their preclinical and clinical development. They also speculate on the future of Lm-based tumour immunotherapies. The article is based on literature published on PubMed and data reported in clinical trials.

Expert opinion: Attenuated strains of Listeria monocytogenes have safely been applied as therapeutic bacterial vectors for the delivery of cancer vaccines. These vectors stimulate MHCI and MHCII pathways as well as the proliferation of antigen-specific T lymphocytes. Several preclinical studies have demonstrated the potency of Lm in intracellular gene and protein delivery in vitro and in vivo. They have also indicated safety and efficiacy in clinical trials. Readers should be aware that the ability of attenuated Lm strains to induce potent immune responses depends on the type of deleted or inactivated Lm virulent gene or genes.

KEYWORDS:

• Bacterial vectors
• Listeria
• attenuation
• safety
• anti-cancer vaccines
• mechanisms of action

Article highlights

• Listeria monocytogenes (Lm) is able to elicit an immune response against tumor-specific antigens

• Preclinical studies have highlighted the potency of Lm for intracellular gene or protein delivery in vitro and in vivo

• Attenuated Lm strains are different at inducing potent immune responses dependent on the type of deleted or inactivated Lm virulent gene (s)

• Listeria monocytogenes showed safety and efficacy in clinical trials

• Lm is an ideal vector for antigen delivery and its presentation through both the MHC class I and II antigen-processing pathways

This box summarizes key points contained in the article.

Acknowledgments

The authors thank Saied Reza Naddaf of the Pasteur Institute of Iran for his assistance in editing the language of this manuscript.

Declaration of interest

The authors are all employees of the Pasteur Institute of Iran. The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This manuscript has not been funded.