Phanthaphol Nattaporn, Somboonpatarakun Chalermchai, Suwanchiwasiri Kwanpirom, Chieochansin Thaweesak, Sujjitjoon Jatuporn, Wongkham Sopit, Maher John, Junking Mutita, Yenchitsomanus Pa-Thai
Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Siriraj Center of Research Excellence for Cancer Immunotherapy (SiCORE-CIT), Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Front Oncol. 2021 Mar 3;11:657868. doi: 10.3389/fonc.2021.657868. eCollection 2021.
Cholangiocarcinoma (CCA) is a lethal bile duct cancer that responds poorly to current standard treatments. A new therapeutic approach is, therefore, urgently needed. Adoptive T cell transfer using chimeric antigen receptor (CAR) T cells is a new therapeutic modality with demonstrated efficacy in hematologic malignancies. However, its efficacy against solid tumors is modest, and further intensive investigation continues. An important factor that influences the success of CAR T cell therapy is the selection of a target antigen that is highly expressed on cancer cells, but markedly less so in normal cells. Integrin αvβ6 is upregulated in several solid tumors, but is minimally expressed in normal epithelial cells, which suggests integrin αvβ6 as an attractive target antigen for CAR T cell immunotherapy in CCA. We investigated integrin αvβ6 expression in pathological tissue samples from patients with liver fluke-associated CCA. We then created CAR T cells targeting integrin αvβ6 and evaluated their anti-tumor activities against CCA cells. We found overexpression of the integrin αvβ6 protein in 23 of 30 (73.3%) CCA patient tissue samples. Significant association between high integrin αvβ6 expression and short survival time ( = 0.043) was also observed. Lentiviral constructs were engineered to encode CARs containing an integrin αvβ6-binding peptide (A20) derived from foot-and-mouth disease virus fused with a second-generation CD28/CD3ζ signaling domain (A20-2G CAR) or with a fourth-generation CD28/4-1BB/CD27/CD3ζ signaling domain (A20-4G CAR). The A20-2G and A20-4G CARs were highly expressed in primary human T cells transduced with the engineered lentiviruses, and they exhibited high levels of cytotoxicity against integrin αvβ6-positive CCA cells ( < 0.05). Interestingly, the A20-2G and A20-4G CAR T cells displayed anti-tumor function against integrin αvβ6-positive CCA tumor spheroids ( < 0.05). Upon specific antigen recognition, A20-4G CAR T cells produced a slightly lower level of IFN-γ, but exhibited higher proliferation than A20-2G CAR T cells. Thus, the A20-4G CAR T cells with lower level of cytokine production, but with higher proliferation represents a promising potential adoptive T cell therapy for integrin αvβ6-positive CCA.
胆管癌（CCA）是一种致命的胆管癌，对当前的标准治疗反应不佳。因此，迫切需要一种新的治疗方法。使用嵌合抗原受体（CAR）T细胞进行过继性T细胞转移是一种新的治疗方式，已在血液系统恶性肿瘤中显示出疗效。然而，其对实体瘤的疗效一般，仍在进一步深入研究。影响CAR T细胞治疗成功的一个重要因素是选择在癌细胞上高表达而在正常细胞中明显低表达的靶抗原。整合素αvβ6在几种实体瘤中上调，但在正常上皮细胞中表达极低，这表明整合素αvβ6是CCA中CAR T细胞免疫治疗的一个有吸引力的靶抗原。我们研究了肝吸虫相关性CCA患者病理组织样本中整合素αvβ6的表达。然后我们构建了靶向整合素αvβ6的CAR T细胞，并评估了它们对CCA细胞的抗肿瘤活性。我们发现30例CCA患者组织样本中有23例（73.3%）整合素αvβ6蛋白过表达。还观察到整合素αvβ6高表达与较短生存时间之间存在显著关联（P = 0.043）。构建慢病毒载体以编码含有源自口蹄疫病毒的整合素αvβ6结合肽（A20）并与第二代CD28/CD3ζ信号域（A20 - 2G CAR）或第四代CD28/4 - 1BB/CD27/CD3ζ信号域（A20 - 4G CAR）融合的CAR。A20 - 2G和A20 - 4G CAR在经工程化慢病毒转导的原代人T细胞中高表达，并且它们对整合素αvβ6阳性的CCA细胞表现出高水平的细胞毒性（P < 0.05）。有趣的是，A20 - 2G和A20 - 4G CAR T细胞对整合素αvβ6阳性的CCA肿瘤球体显示出抗肿瘤功能（P < 0.05）。在特异性抗原识别后，A20 - 4G CAR T细胞产生的IFN - γ水平略低，但比A20 - 2G CAR T细胞表现出更高的增殖能力。因此，细胞因子产生水平较低但增殖能力较高的A20 - 4G CAR T细胞代表了一种有前景的针对整合素αvβ6阳性CCA的过继性T细胞治疗方法。
