Listeriolysin O as a strong immunogenic molecule for the development of new anti-tumor vaccines

Abstract

The pore-forming toxin listeriolysin O (LLO), which is produced by Listeria monocytogenes, mediates bacterial phagosomal escape and facilitates bacterial multiplication during infection. This toxin has recently gained attention because of its confirmed role in the controlled and specific modulation of the immune response. Currently, cancer immunotherapies are focused on conquering the immune tolerance induced by poorly immunogenic tumor antigens and eliciting strong, lasting immunological memory. An effective way to achieve these goals is the co-administration of potent immunomodulatory adjuvant components with vaccine vectors. LLO, a toxin that belongs to the family of cholesterol-dependent cytolysins (CDCs), exhibits potent cell type-non-specific toxicity and is a source of dominant CD4⁺ and CD8⁺ T cell epitopes. According to recent research, in addition to its effective cytotoxicity as a cancer immunotherapeutic drug, the non-specific adjuvant property of LLO makes it promising for the development of efficacious anti-tumor vaccines.

Keywords: :

• Listeria
• LLO
• pore-forming toxin
• cytotoxicity
• immunogenicity
• anti-tumor vaccine
• cancer immunotherapy

Disclosure of Potential Conflicts of Interest

The authors are engaging in one research of a broad-spectrum cancer vaccine project granted by Cell Resource Center of Chinese Academy of Medical Sciences. The authors declare they have no conflict of interest and no financial interest with the subject matter or materials discussed in the manuscript.

Acknowledgments

We are very grateful to the information provided by Cell Resource Center, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, and sincerely thanks to the resources of ExPASy system of SIB Bioinformatics Resource, Protein Data Bank and SWISS-MODEL Workspace.