Assessing the Antitumor Immune Effects of Gut Microbiota in a Preclinical Melanoma Model

Antitumor immune responses are regulated by a multitude of factors, including the gut microbiota. Specific bacterial taxa and metabolites have been correlated with improved responses to immune checkpoint inhibitor therapy in melanoma patients. Gut microbiota and microbiota-derived metabolites can modulate antitumor immune responses by increasing antigen presentation capabilities and enhancing cytotoxic T-cell effector functions. To assess the effects of gut microbiota on antitumor immune responses, we optimized the following protocols focused on immune checkpoint inhibitor therapy in a preclinical melanoma model. Analysis of tumor-infiltrating and circulating lymphocytes, bacterial translocation and growth, and immune cell activation provides a foundation for microbiota/cancer immunology research.