Bacterial outer membrane vesicles OMV-LL for delivery of neoantigen mRNA to induce anti-HCC therapy

Hepatocellular carcinoma (HCC) represents a significant health challenge, with immunotherapy serving as a crucial component of its complex treatment regimen. This study investigates the use of TP53Y220C as a preferred antigen to induce cytotoxic T lymphocytes (CTLs) for cytotoxic effects against HCC.

The TP53_Y220C mRNA (mTP53_Y220C) was synthesized through an in vitro transcription method and subsequently introduced into dendritic cells (DCs) using bacterial outer membrane vesicles expressing L7Ae and Listeria monocytogenes lysin O (OMV-LL), electroporation, and lipid nanoparticles, respectively. Co-culture of differently treated DCs with initial T cells induces CTLs. The cytotoxic effects of CTLs on hepatocellular carcinoma were evaluated through experiments such as flow cytometry and mouse tumour models.

We assessed the therapeutic efficacy of CTLs, activated by mTP53_Y220C-loaded DCs, in a murine model of HCC. Results demonstrate that CTLs, activated by DCs loaded with mTP53_Y220C via OMV-LL or electroporation, effectively initiated immune responses against HCC. While OMV-LL were less efficient than electroporation in mRNA delivery, they induced a significant pro-inflammatory response and activated the innate immune system.

This study highlights OMV-LL as an innovative mRNA delivery approach to DCs for CTLs activation and demonstrates their potential in CTLs-based therapy for HCC.