背景:在实体恶性肿瘤中使用嵌合抗原受体(CAR)工程化细胞疗法获得阳性结果仍然具有挑战性,例如结直肠癌(CRC)和胰腺导管腺癌(PDAC)。主要障碍是缺乏健康组织不共享的可靶向表面抗原。CD70成为有趣的目标,由于其在健康组织中的严格表达模式及其在大量恶性肿瘤中的肿瘤进展中的明显作用。此外,CD70也在癌症相关成纤维细胞(CAF)上表达,CRC和PDAC治疗效果的另一个障碍。我们探索了CD70作为CRC中CAR自然杀伤(NK)细胞治疗靶标的治疗潜力,PDAC,专注于肿瘤细胞和CAFs,和淋巴瘤。
方法:使用患者样本的RNA-seq数据和免疫组织化学分析来探索CRC和PDAC患者中CD70的表达。此外,开发了靶向CD70的CARNK细胞来评估针对CD70+肿瘤细胞和CAFs的细胞毒活性。并评价细胞因子刺激对其疗效的影响。针对一组具有不同CD70表达的肿瘤和CAF细胞系研究了CD70-CARNK细胞的体外功能性。携带淋巴瘤的小鼠用于验证CD70-CARNK细胞的体内效力。最后,为了考虑患者的变异性,在含有CAF的患者来源的类器官上测试CD70-CARNK细胞。
结果:在这项研究中,我们确定CD70是CRC和PDAC患者肿瘤细胞和CAFs的靶点.CD70导向的CARNK细胞的功能评估表明,IL-15刺激对于获得CD70+肿瘤细胞和CAFs的有效消除至关重要。并改善携带CD70+肿瘤的小鼠的肿瘤负荷和存活率。机械上,IL-15刺激通过上调CAR表达和增加促炎细胞因子的分泌,导致CD70-CARNK细胞的效力提高。主要以自分泌或细胞内的方式。
结论:我们公开了CD70作为血液肿瘤和实体瘤中的有吸引力的靶标。IL-15装甲的CARNK细胞作为有效的效应子消除这些CD70+细胞。它们可以靶向CRC和PDAC患者的肿瘤细胞和CAFs,和其他潜在的促纤维化实体瘤。
It remains challenging to obtain positive outcomes with chimeric antigen receptor (CAR)-engineered cell therapies in solid malignancies, like colorectal cancer (CRC) and pancreatic ductal adenocarcinoma (PDAC). A major obstacle is the lack of targetable surface antigens that are not shared by healthy tissues. CD70 emerges as interesting target, due to its stringent expression pattern in healthy tissue and its apparent role in tumor progression in a considerable amount of malignancies. Moreover, CD70 is also expressed on cancer-associated fibroblasts (CAFs), another roadblock for treatment efficacy in CRC and PDAC. We explored the therapeutic potential of CD70 as target for CAR natural killer (NK) cell therapy in CRC, PDAC, focusing on tumor cells and CAFs, and lymphoma.
RNA-seq data and immunohistochemical analysis of patient samples were used to explore CD70 expression in CRC and PDAC patients. In addition, CD70-targeting CAR NK cells were developed to assess cytotoxic activity against CD70+ tumor cells and CAFs, and the effect of cytokine stimulation on their efficacy was evaluated. The in vitro functionality of CD70-CAR NK cells was investigated against a panel of tumor and CAF cell lines with varying CD70 expression. Lymphoma-bearing mice were used to validate in vivo potency of CD70-CAR NK cells. Lastly, to consider patient variability, CD70-CAR NK cells were tested on patient-derived organoids containing CAFs.
In this study, we identified CD70 as a target for tumor cells and CAFs in CRC and PDAC patients. Functional evaluation of CD70-directed CAR NK cells indicated that IL-15 stimulation is essential to obtain effective elimination of CD70+ tumor cells and CAFs, and to improve tumor burden and survival of mice bearing CD70+ tumors. Mechanistically, IL-15 stimulation resulted in improved potency of CD70-CAR NK cells by upregulating CAR expression and increasing secretion of pro-inflammatory cytokines, in a mainly autocrine or intracellular manner.
We disclose CD70 as an attractive target both in hematological and solid tumors. IL-15 armored CAR NK cells act as potent effectors to eliminate these CD70+ cells. They can target both tumor cells and CAFs in patients with CRC and PDAC, and potentially other desmoplastic solid tumors.