嵌合抗原受体自然杀伤（CAR-NK）疗法在治疗血液肿瘤方面具有广阔的前景，但由于缺乏合适的靶点以及工程化 NK 细胞的浸润性差，其在实体瘤中的疗效有限。在此，我们探讨药物处理后从内质网易位到细胞表面的免疫原性细胞死亡（ICD）标记物ERp57是否可以作为CAR-NK治疗的靶点。为了靶向ERp57，使用VHH噬菌体展示文库筛选ERp57-靶向纳米抗体（Nbs）。与人和小鼠 ERp57 具有高结合亲和力的候选 Nb 用于构建 CAR-NK 细胞。我们进行了各种体外和体内研究来评估构建的 CAR-NK 细胞的抗肿瘤功效。我们证明 ERp57 的易位不仅可以通过低剂量奥沙利铂 (OXP) 治疗诱导，而且可以在细胞上自发表达。各种类型肿瘤细胞系的表面。我们的结果表明，G6-CAR-NK92 细胞可以在体外有效杀死各种诱导或内在表达 ERp57 的肿瘤细胞系，并且在癌细胞来源的异种移植和患者来源的异种移植小鼠模型中也表现出有效的抗肿瘤作用。此外，低剂量ICD诱导药物OXP可协同增强G6-CAR-NK92细胞的抗肿瘤活性。总的来说，我们的研究结果表明ERp57可以作为CAR-NK靶向的新肿瘤抗原，并且所得结果通过与 ICD 诱导药物相结合，CAR-NK 细胞有潜力成为多种癌症的广谱免疫细胞疗法。© 作者（或其雇主）2024。CC BY 允许重复使用-NC。不得商业再利用。请参阅权利和权限。英国医学杂志出版。

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.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.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.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.© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.