Exosomal PD-L1 detection in cancer predictive biomarker for response to immune checkpoint blockade therapy
Tetsuichi Kansha, Shuai Ma, Hao Wang, Xiaotong Yu, Ying Song, Zhengyang Guo, Jiagui Song, Lixiang Xue, Jianling Yang
Abstract
Programmed death-ligand 1 (PD-L1) carried by tumor-derived exosomes has emerged as a critical mediator of immune evasion and resistance to immune checkpoint blockade therapy. Unlike membrane-bound PD-L1, exosomal PD-L1 is systemically distributed and capable of suppressing T cell activity at distant sites. This review summarizes the current understanding of exosomal PD-L1 biogenesis, its immunosuppressive mechanisms, and its clinical relevance across multiple cancer types. We highlight its potential as a non-invasive biomarker for predicting therapeutic response and monitoring disease progression. Compared with tissue-based PD-L1 assessment, exosomal PD-L1 offers advantages in accessibility and dynamic reflection of tumor immune status. However, challenges remain regarding standardization of detection methods and clinical interpretation. Future directions include the integration of exosomal PD-L1 profiling into immunotherapy decision-making and the development of therapeutic strategies targeting exosome secretion. These insights may contribute to overcoming resistance in immunologically inert tumors and advancing precision oncology.