Eradication of Triple-Negative Breast Cancer Cells by Targeting Glycosylated PD-L1

Publication date: 12 February 2018
Source:Cancer Cell, Volume 33, Issue 2
Author(s): Chia-Wei Li, Seung-Oe Lim, Ezra M. Chung, Yong-Soo Kim, Andrew H. Park, Jun Yao, Jong-Ho Cha, Weiya Xia, Li-Chuan Chan, Taewan Kim, Shih-Shin Chang, Heng-Huan Lee, Chao-Kai Chou, Yen-Liang Liu, Hsin-Chih Yeh, Evan P. Perillo, Andrew K. Dunn, Chu-Wei Kuo, Kay-Hooi Khoo, Jennifer L. Hsu, Yun Wu, Jung-Mao Hsu, Hirohito Yamaguchi, Tzu-Hsuan Huang, Aysegul A. Sahin, Gabriel N. Hortobagyi, Stephen S. Yoo, Mien-Chie Hung
Protein glycosylation provides proteomic diversity in regulating protein localization, stability, and activity; it remains largely unknown whether the sugar moiety contributes to immunosuppression. In the study of immune receptor glycosylation, we showed that EGF induces programmed death ligand 1 (PD-L1) and receptor programmed cell death protein 1 (PD-1) interaction, requiring β-1,3-N-acetylglucosaminyl transferase (B3GNT3) expression in triple-negative breast cancer. Downregulation of B3GNT3 enhances cytotoxic T cell-mediated anti-tumor immunity. A monoclonal antibody targeting glycosylated PD-L1 (gPD-L1) blocks PD-L1/PD-1 interaction and promotes PD-L1 internalization and degradation. In addition to immune reactivation, drug-conjugated gPD-L1 antibody induces a potent cell-killing effect as well as a bystander-killing effect on adjacent cancer cells lacking PD-L1 expression without any detectable toxicity. Our work suggests targeting protein glycosylation as a potential strategy to enhance immune checkpoint therapy.

Teaser

Li et al. show that glycosylation of PD-L1 is essential for PD-L1/PD-1 interaction and immunosuppression in triple-negative breast cancer (TNBC). They generate a glycosylation-specific antibody that induces PD-L1 internalization and an antibody-drug conjugate with potent anti-tumor activities in TNBC models.


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