AI Summary
The study explores the use of immunogenic cell death (ICD) marker ERp57 as a target for Chimeric antigen receptor natural killer (CAR-NK) therapy in solid tumors. The research demonstrates that ERp57 translocated to the cell surface after drug treatment can be targeted using CAR-NK cells, leading to robust antitumor activity in various tumor cell lines. The efficacy of the CAR-NK cells is further enhanced by combining them with the ICD-inducible drug Oxaliplatin (OXP). This suggests that ERp57 may serve as a new tumor antigen for CAR-NK targeting, providing potential broad-spectrum immune cell therapy for various cancers when used in combination with ICD inducer drugs.
Background
Chimeric antigen receptor natural killer (CAR-NK) therapy holds great promise for treating hematologic tumors, but its efficacy in solid tumors is limited owing to the lack of suitable targets and poor infiltration of engineered NK cells. Here, we explore whether immunogenic cell death (ICD) marker ERp57 translocated from endoplasmic reticulum to cell surface after drug treatment could be used as a target for CAR-NK therapy.
Methods
To target ERp57, a VHH phage display library was used for screening ERp57-targeted nanobodies (Nbs). A candidate Nb with high binding affinity to both human and mouse ERp57 was used for constructing CAR-NK cells. Various in vitro and in vivo studies were performed to assess the antitumor efficacy of the constructed CAR-NK cells.
Results
We demonstrate that the translocation of ERp57 can not only be induced by low-dose oxaliplatin (OXP) treatment but also is spontaneously expressed on the surface of various types of tumor cell lines. Our results show that G6-CAR-NK92 cells can effectively kill various tumor cell lines in vitro on which ERp57 is induced or intrinsically expressed, and also exhibit potent antitumor effects in cancer cell-derived xenograft and patient-derived xenograft mouse models. Additionally, the antitumor activity of G6-CAR-NK92 cells is synergistically enhanced by the low-dose ICD-inducible drug OXP.
Conclusion
Collectively, our findings suggest that ERp57 can be leveraged as a new tumor antigen for CAR-NK targeting, and the resultant CAR-NK cells have the potential to be applied as a broad-spectrum immune cell therapy for various cancers by combining with ICD inducer drugs.