Reinvigoration of cytotoxic T lymphocytes in microsatellite instability-high colon adenocarcinoma through lysosomal degradation of PD-L1

作者：Dan Liu, Jin Yan, Fang Ma, Jingmei Wang, Siqi Yan, Wangxiao He · 发表于：Nature Communications · 年份：2024 · DOI：10.1038/s41467-024-51386-7 · 被引用次数：11 · 研究领域：Monoclonal and Polyclonal Antibodies Research、Peptidase Inhibition and Analysis、Glycosylation and Glycoproteins Research

Compensation and intracellular storage of PD-L1 may compromise the efficacy of antibody drugs targeting the conformational blockade of PD1/PD-L1 on the cell surface. Alternative therapies aiming to reduce the overall cellular abundance of PD-L1 thus might overcome resistance to conventional immune checkpoint blockade. Here we show by bioinformatics analysis that colon adenocarcinoma (COAD) with high microsatellite instability (MSI-H) presents the most promising potential for this therapeutic intervention, and that overall PD-L1 abundance could be controlled via HSC70-mediated lysosomal degradation. Proteomic and metabolomic analyses of mice COAD with MSI-H in situ unveil a prominent acidic tumor microenvironment. To harness these properties, an artificial protein, IgP β, is engineered using pH-responsive peptidic foldamers. This features customized peptide patterns and designed molecular function to facilitate interaction between neoplastic PD-L1 and HSC70. IgP β effectively reduces neoplastic PD-L1 levels via HSC70-mediated lysosomal degradation, thereby persistently revitalizing the action of tumor-infiltrating CD8 + T cells. Notably, the anti-tumor effect of lysosomal-degradation-based therapy surpasses that of antibody-based immune checkpoint blockade for MSI-H COAD in multiple mouse models. The presented strategy expands the use of peptidic foldamers in discovering artificial protein drugs for targeted cancer immunotherapy. The efficiency of antibody-based immune checkpo...