通过 pHLIP 肽将替代抗原嫁接到肿瘤细胞表面以将 CAR-T 细胞治疗普适性靶向实体瘤

CAR-T cells and monoclonal antibodies (mAbs) are immunotherapeutics that have shown efficacies against certain malignancies.

However, their broad application is hindered by the scarcity of tumor-associated antigens on tumor cell surfaces. Previous investigations unveiled the unique capacity of pH-low insertion peptide (pHLIP) to anchor to plasma membranes under acidic conditions. Considering that an acidic tumor microenvironment is a hallmark of solid tumors, we engineered a novel peptide, Myc-pHLIP, by tethering a surrogate epitope tag, the c-Myc-tag, to pHLIP.

We evaluated the efficiency of Myc-pHLIP in inserting the artificial c-Myc-tag onto the plasma membrane of malignant cells and determined if this engraftment could convert it into a therapeutic target for CAR-T cells or mAbs.

Our in vitro experiments demonstrated that incubating Myc-pHLIP with tumor cells in acidic media triggered significant killing by either Myc-targeted CAR-T cells (Myc-CAR-T), or by an anti-Myc mAb in the presence of NK cells. In vivo studies demonstrated substantial antitumor effects with sequential administration of Myc-pHLIP followed by either Myc-CAR-T or Myc-mAb.

These findings establish that Myc-pHLIP has the potential to act as a universal surrogate tumor antigen capable of directing CAR-T cells or mAbs to treat any solid tumors by concurrently targeting both malignant and stromal cells.