Comprehensive single-cell analysis demonstrates radiotherapy-induced infiltration of macrophages expressing immunosuppressive genes into tumor in esophageal squamous cell carcinoma
Hidekazu Oyoshi, Junyan Du, Shunsuke A. Sakai, Riu Yamashita, Masayuki Okumura, Atsushi Motegi, Hidehiro Hojo, Masaki Nakamura, Hidenari Hirata, Hironori Sunakawa, Daisuke Kotani, Tomonori Yano, Takashi Kojima, Yuka Nakamura, Motohiro Kojima, Ayako Suzuki, Junko Zenkoh, Katsuya Tsuchihara, Tetsuo Akimoto, Atsushi Shibata, Yutaka Suzuki, Shun‐Ichiro Kageyama
Abstract
Radiotherapy (RT) combined with immunotherapy is promising; however, the immune response signature in the clinical setting after RT remains unclear. Here, by integrative spatial and single-cell analyses using multiplex immunostaining (CODEX), spatial transcriptome (VISIUM), and single-cell RNA sequencing, we substantiated the infiltration of immune cells into tumors with dynamic changes in immunostimulatory and immunosuppressive gene expression after RT. In addition, our comprehensive analysis uncovered time- and cell type-dependent alterations in the gene expression profile after RT. Furthermore, myeloid cells showed prominent up-regulation of immune response-associated genes after RT. Notably, a subset of infiltrating tumor-associated myeloid cells showing PD-L1 positivity exhibited significant up-regulation of immunostimulatory (HMGB1 and ISG15), immunosuppressive (SIRPA and IDO1), and protumor genes (CXCL8, CCL3, IL-6, and IL-1AB), which can be targets of immunotherapy in combination with PD-L1. These datasets will provide information on the RT-induced gene signature to seek an appropriate target for personalized immunotherapy combined with RT and guide the timing of combination therapy.