Abstract IA05: Microbiota, metabolites, and antitumor immunity

The intestinal microbiome heavily influences development and regulation of the immune system. The microbiome, which includes bacteria, viruses, and fungi, can also influence the initiation, development, and progression of cancer, with modulation of the immune system as one of the key pathways involved. Gut bacteria have also been found to alter the efficacy of cancer therapies, including immune checkpoint blockade therapy. These immunotherapies utilize the therapeutic potential of the immune system and have revolutionized cancer treatment. Yet this promising new strategy is not effective in all individuals (or all cancers) and has shown poor efficacy in colorectal cancer. We therefore investigated whether the intestinal microbiota could play a role in modulating immunotherapy in mouse models of colorectal cancers. We have identified specific intestinal commensal bacteria and a bacterial metabolite that control the efficacy of immune checkpoint blockade in animal models of colorectal cancer. In this session I will discuss the cellular and molecular pathways involved in this novel microbiota-microbe-immune pathway and describe the potential of bacteria-checkpoint blockade cotherapies.

Citation Format: Kathy D. McCoy. Microbiota, metabolites, and antitumor immunity [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr IA05.