Make solid tumor cells look like a virus for the immune system to kill them

Good news! Cancer is history (soon)! This seems to be a clever approach!

"Solid tumour cells tagged with fragments of the hepatitis B virus can be killed by T cells trained to target this virus. Researchers created T cells with a memory of hepatitis B proteins using an mRNA vaccine. Then, they genetically engineered a defective vaccinia virus — similar to the virus used in the smallpox vaccine — that would replicate inside tumour cells and express hepatitis B proteins on the cell surface. These became beacons for the defensive antiviral T cells, which then attacked and killed the cancer. In mice, this strategy increased survival by reducing the recurrence and spread of multiple tumour types."

From the 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."

Nature Briefing: Cancer

HBsAg-tagged tumour vaccine system eliminates solid tumours through virus-specific memory T cells (no public access, but article above contains link to PDF)