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

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.