AUTHOR=Xu Huimin , Piao Linghua , Wu Yundi , Liu Xiande 

TITLE=IFN-γ enhances the antitumor activity of attenuated salmonella-mediated cancer immunotherapy by increasing M1 macrophage and CD4 and CD8 T cell counts and decreasing neutrophil counts

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2022.996055

DOI=10.3389/fbioe.2022.996055

ISSN=2296-4185

ABSTRACT=<p>Bacteria-mediated cancer immunotherapy (BCI) inhibits tumor progression and has a synergistic antitumor effect when combined with chemotherapy. The anti- or pro-tumorigenic effects of interferon-γ (IFN-γ) are controversial; hence, we were interested in the antitumor effects of IFN-γ/BCI combination therapy. Here, we demonstrated that IFN-γ increased the tumor cell killing efficacy of attenuated <italic>Salmonella</italic> by prolonging the survival of tumor-colonizing bacteria <italic>via</italic> blockade of tumor-infiltrating neutrophil recruitment. In addition, IFN-γ attenuated <italic>Salmonella</italic>-stimulated immune responses by stimulating tumor infiltration by M1-like macrophages and CD4<sup>+</sup> and CD8<sup>+</sup> T cells, thereby facilitating tumor eradication. Taken together, these findings suggest that combination treatment with IFN-γ boosts the therapeutic response of BCI with S. tΔppGpp, suggesting that IFN-γ/BCI is a promising approach to immunotherapy.</p>