Protocol for analyzing tumor-infiltrating bystander CD8+ T cells in mice using adoptive transfer of P14 TCR-transgenic CD8+ T cells

While tumor-specific CD8 + T cells become functionally exhausted within the tumor microenvironment (TME), virus-specific bystander memory CD8 + T (T BYS ) cells are abundant and represent valuable immunotherapy targets. Here, we present a protocol to analyze tumor-infiltrating virus-specific T BYS cells in murine tumor models using P14 CD8 + T cells. We describe steps for monitoring long-term in vivo behavior of P14 T BYS cells and characterizing their differentiation trajectories and functional heterogeneity. For complete details on the use and execution of this protocol, please refer to Lin et al. 1