Local vaccination and systemic tumor suppression via irradiation and manganese adjuvant in mice

TL;DR

This study demonstrates that irradiation combined with manganese adjuvant in mice can induce a systemic tumor vaccination effect, significantly suppressing tumor growth and metastasis, suggesting new strategies for cancer radiotherapy and immunotherapy.

Contribution

First to report high-efficiency systemic tumor vaccination induced by irradiation and manganese adjuvant in mice, offering new insights for cancer treatment strategies.

Findings

Untreated tumor cells failed to grow after vaccination in mice.

Irradiation with proton or gamma-ray enhances immune response.

Systemic tumor suppression observed with manganese adjuvant.

Abstract

Presently 4T-1 luc cells were irradiated with proton under ultra-high dose rate FLASH or with gamma-ray with conventional dose rate, and then subcutaneous vaccination with or without Mn immuno-enhancing adjuvant into the mice for three times. One week later, we injected untreated 4T-1 luc cells on the other side of the vaccinated mice, and found that the untreated 4T-1 luc cells injected later nearly totally did not grow tumor (1/17) while controls without previous vaccination all grow tumors (18/18). The result is very interesting and the findings may help to explore in situ tumor vaccination as well as new combined radiotherapy strategies to effectively ablate primary and disseminated tumors. To our limited knowledge, this is the first paper reporting the high efficiency induction of systemic vaccination suppressing the metastasized/disseminated tumor progression.