Characterization of Natural Killer cells infiltrating irradiated murine tumors through flow cytometry

The radiation-induced immune response is increasingly well documented. However, some aspects remain unclear, notably the role of Natural Killer (NK) cells, a subgroup of innate lymphoid cells involved in the antitumor response, in the response to RT. It therefore seems necessary to better characterize NK cells infiltrating irradiated tumors in order to better understand the mechanisms of action of RT, enabling its subsequent optimization and combination with other immunomodulatory treatments. A key technology for studying intratumoral immune cells is flow cytometry, which can simultaneously quantify and analyze the phenotype of numerous cells. Here, we propose a method for phenotyping intratumoral NK cells through flow cytometry in mice bearing colorectal tumors treated with radiotherapy. This procedure can also be used to study the radiation-induced NK cell response in a wide range of solid tumors.