Antitumor memory T cell in mice quantified by bulk T-cell receptor clonal analysis

Tumor-specific memory T cells play a crucial role in the immune system's ability to recognize and eliminate cancer cells. Using the bulk TCR clonal analysis in mice cured with oncolytic immunotherapy, we identified an oligoclonal antitumor CD4 and CD8 memory T cells. Adoptive transfer demonstrated that high amplitude responding T cells were tumor-specific. Tetramer analysis confirmed that clonotype frequency determined by TCR analysis closely approximated cell clone frequency. The mean frequency of resting anti-tumor memory CD4 T- cells in the unchallenged spleen were 0.028%, and of memory CD8 T-cells was 0.11% which was not high enough to distinguish them from the background. The methodology can be developed to use blood and tissue sampling to rapidly quantify the effectiveness of a tumor vaccine or any vaccine-generating therapeutic T-cells.