HBsAg-tagged tumour vaccine system eliminates solid tumours through virus-specific memory T cells

Nat Biomed Eng. 2025 Nov 17. doi: 10.1038/s41551-025-01555-w. Online ahead of print.

Abstract

It is challenging for cancer vaccines to identify immunogenic antigens that are specifically and uniformly expressed on heterogeneous solid tumours and that can elicit production of T cells to lyse antigen-positive tumour cells and expand within the immunosuppressive tumour microenvironment. In contrast, microbial antigens are well-defined and robustly immunogenic and can activate specific memory T cells to eliminate microbes within the tumour microenvironment. Inspired by this, we developed a hepatitis B surface antigen (HBsAg)-tagged tumour vaccine system (H-TVAC). H-TVAC leverages HBsAg-specific memory T cells from a HBsAg mRNA vaccine to target and lyse HBsAg-tagged tumour cells using the vaccinia virus. This approach also elicits a tumour-specific immune response through epitope spreading by recruiting dendritic cells, thereby eliminating heterogeneous solid tumours. In various preclinical murine models, including the B16-OVA, B16F10, MC38, CT26, 4T1 and H22 hepatocellular carcinoma, as well as a B16F10 bilateral tumour model, H-TVAC demonstrates anti-tumour immune responses, improved survival rates and reduced metastasis and recurrence.