# Engineering bioactive mineralized tumor cells for tumor immunotherapy

## TL;DR

This study introduces a new tumor vaccine using mineralized tumor cells and CpG to boost immune responses and significantly reduce tumor growth in mice.

## Contribution

A novel vaccine combining manganese-mineralized tumor cells and CpG to enhance dendritic cell maturation and tumor suppression.

## Key findings

- The vaccine reduced tumor volume to one-fifth of the control group in B16F10 tumor-bearing mice.
- It significantly extended survival to day 30 in the tested mice.
- The vaccine increased immune cell infiltration and cytokine production in the tumor microenvironment.

## Abstract

Whole-cell tumor vaccines are advantageous because of their ability to induce a broad and multifaceted immune response through the presentation of a wide range of tumor antigens, thereby enhancing the ability of the immune system to recognize and target cancerous cells.

In this study, we present a multifunctional vaccine that consists of manganese-mineralized tumor cells and positively charged polymer-immobilized CpG. The Mn2+ and CpG released from the engineered vaccine facilitate the maturation of dendritic cells through the activation of the cGAS-STING and TLR9 pathways, respectively.

As a consequence, the engineered vaccine derived from B16F10 cells exhibited a pronounced tumor-suppressive effect, reducing the tumor volume to approximately one-fifth of that in the control group, and significantly extending survival to day 30 in B16F10 tumor-bearing mice. This superior therapeutic outcome is associated with enhanced activation of dendritic cells, increased infiltration of NK and CD8+ T cells, and increased production of immune cytokines within the tumor microenvironment.

Together, our study highlights the immense potential of engineering bioactive mineralized tumor cells to facilitate whole-cell tumor vaccine-based immunotherapy.