CD106 in tumor-specific exhausted CD8+ T cells mediates immunosuppression by inhibiting TCR signaling.

Abstract

T cell exhaustion is a major contributor to immunosuppression in the tumor microenvironment (TME). Blockade of key regulators of T cell exhaustion, such as PD-1, can reinvigorate tumor-specific T cells and activate anti-tumor immunity in various types of cancer. Here, we identified that CD106 was specifically expressed in exhausted CD8+ T cells in the TME using single-cell RNA-sequencing. High CD106 expression in the TME in clinical samples corresponded to improved response to cancer immunotherapy. CD106 in tumor-specific T cells suppressed anti-tumor immunity both in vitro and in vivo, and loss of CD106 in CD8+ T cells suppressed tumor growth and improved response to PD-1 blockade. Mechanistically, CD106 inhibited T-cell receptor (TCR) signaling by interacting with the TCR/CD3 complex and reducing its surface expression. Together, these findings provide insights into the immunosuppressive role of CD106 expressed in tumor-specific exhausted CD8+ T cells, identifying it as a potential biomarker and therapeutic target for cancer immunotherapy.

• Authors: Yuto Naoi, Takao Morinaga, Joji Nagasaki, Ryo Ariyasu, Youki Ueda, Kazuo Yamashita, Wenhao Zhou, Shusuke Kawashima, Katsushige Kawase, Akiko Honobe-Tabuchi, Takehiro Ohnuma, Tatsuyoshi Kawamura, Yoshiyasu Umeda, Yu Kawahara, Yasuhiro Nakamura, Yukiko Kiniwa, Osamu Yamasaki, Satoshi Fukushima, Masahito Kawazu, Yutaka Suzuki, Hiroyoshi Nishikawa, Toyoyuki Hanazawa, Mizuo Ando, Takashi Inozume, Yosuke Togashi
• Journal: Cancer research (Cancer Res) (Apr 18 2024) ISSN: 1538-7445 [Electronic] United States
• PMID: 38635899 (Publication Type: Journal Article)