Figure 1.
Main mechanism by which the gut microbiota influences ICI treatment. The homology between non-self material of the gut microbiota and tumor antigen induces cross-reactivity of T cells. Dendritic cells (DC) recognize the non-self material of gut microbiota, then present the antigen and activate the T cells in the lymph node. Exposure to antigens and central memory T cells (TCM) is formed. Subsequently, accumulated TCM in tumor bed could differentiate to effector T cell and further recruit effector T cells from peripheral circulation. The increased T cell activity has a positive influence on immune checkpoint inhibitor (ICI) treatment.