Abstract 2148: Screening of cancer-reactive T cells in lymph nodes in colorectal cancer patients

Tumor draining lymph nodes (TDLNs) are located in the routes of lymphatic drainage from a primary tumor and have the highest metastasis in various types of solid tumors. TDLNs are considered as a tissue to activate the antitumor immunity, where antigen-specific effector T cells are generated and released to the blood stream. These effector T cells then infiltrate into the tumor site and attack cancer cells. However, it has not been investigated whether cancer-reactive T cells are present in lymph nodes. Through T cell receptor (TCR) repertoire analysis of cancer tissues and total 203 regional lymph nodes from 23 colorectal cancer patients, we previously found that regional lymph nodes, especially metastasis-positive lymph nodes, contain T cells with TCR shared with primary cancer tissues. In this study, we collected surgically-resected fresh cancer tissues and total 12 regional lymph nodes from 4 colorectal cancer patients. From these freshly-obtained cancer tissues and lymph nodes, we isolated single cells and then cultured T cells and patient-derived cancer cells. We co-cultured each of T cells from the 12 lymph nodes with autologous cancer cells, and examined their cancer-reactivity using IFN-γ ELISPOT assay. Six among the 7 metastasis-positive lymph nodes, shows significant production of INF-γ, suggesting the presence of cancer-reactive T cells in the lymph nodes. We also detected cancer-reactive T cells in 3 out of 5 metastasis-negative lymph nodes. In FACS analysis, we found the proportion of TIM3+ cells in CD8+PD1+ T cells were lower in T cells in lymph nodes compared to T cells in primary tumor. These data suggest that lymph nodes may be a good source of T cells for cancer immunotherapy. Citation Format: Kazuma Kiyotani, Kazumi Okamura, Satoshi Nagayama, Yusuke Nakamura. Screening of cancer-reactive T cells in lymph nodes in colorectal cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2148.