Candiolo Cancer Institute, FPO-IRCCS, Strada Provinciale 142 Km 3.95, 10060, Candiolo, TO, Italy.
Department of Oncology, University of Turin, Regione Gonzole 10, 10043, Orbassano, TO, Italy.
J Exp Clin Cancer Res. 2023 Nov 22;42(1):310. doi: 10.1186/s13046-023-02884-x.
Even acknowledging the game-changing results achieved in the treatment of metastatic melanoma with the use of immune checkpoint inhibitors (ICI), a large proportion of patients (40-60%) still fail to respond or relapse due to the development of resistance. Alterations in the expression of Human Leukocyte Antigen class I (HLA-I) molecules are considered to play a major role in clinical resistance to ICI. Cellular immunotherapy with HLA-independent CAR-redirected lymphocytes is a promising alternative in this challenging setting and dedicated translational models are needed.
In this study, we propose an HLA-independent therapeutic strategy with Cytokine Induced Killer lymphocytes (CIK) genetically engineered with a Chimeric Antigen Receptor (CAR) targeting the tumor antigen CSPG4 as effector mechanism. We investigated the preclinical antitumor activity of CSPG4-CAR.CIK in vitro and in a xenograft murine model focusing on patient-derived melanoma cell lines (Mel) with defective expression of HLA-I molecules.
We successfully generated CSPG4-CAR.CIK from patients with metastatic melanoma and reported their intense activity in vitro against a panel of CSPG4-expressing patient-derived Mel. The melanoma killing activity was intense, even at very low effector to target ratios, and not influenced by the expression level (high, low, defective) of HLA-I molecules on target cells. Furthermore, CAR.CIK conditioned medium was capable of upregulating the expression of HLA-I molecules on melanoma cells. A comparable immunomodulatory effect was replicated by treatment of Mel cells with exogenous IFN-γ and IFN-α. The antimelanoma activity of CSPG4-CAR.CIK was successfully confirmed in vivo, obtaining a significant tumor growth inhibition of an HLA-defective Mel xenograft in immunodeficient mice.
In this study we reported the intense preclinical activity of CSPG4-CAR.CIK against melanoma, including those with low or defective HLA-I expression. Our findings support CSPG4 as a valuable CAR target in melanoma and provide translational rationale for clinical studies exploring CAR-CIK cellular immunotherapies within the challenging setting of patients not responsive or relapsing to immune checkpoint inhibitors.
尽管免疫检查点抑制剂 (ICI) 的应用在转移性黑色素瘤的治疗中取得了改变游戏规则的结果，但仍有很大一部分患者（40-60%）由于耐药性的发展而无法响应或复发。人类白细胞抗原 I 类 (HLA-I) 分子表达的改变被认为在临床对 ICI 的耐药性中起主要作用。在这种具有挑战性的环境中，使用 HLA 非依赖性 CAR 重定向淋巴细胞的细胞免疫疗法是一种很有前途的替代方法，需要专门的转化模型。
在这项研究中，我们提出了一种 HLA 非依赖性治疗策略，使用细胞因子诱导的杀伤细胞（CIK）作为效应机制，对靶向肿瘤抗原 CSPG4 的嵌合抗原受体（CAR）进行基因工程改造。我们研究了 CSPG4-CAR.CIK 在体外和异种移植小鼠模型中的抗肿瘤活性，重点是针对 HLA-I 分子表达缺陷的患者来源黑色素瘤细胞系（Mel）。
我们成功地从转移性黑色素瘤患者中生成了 CSPG4-CAR.CIK，并报告了它们在体外对一组表达 CSPG4 的患者来源 Mel 的强烈活性。即使在非常低的效应物与靶细胞的比例下，黑色素瘤杀伤活性也很强烈，并且不受靶细胞上 HLA-I 分子表达水平（高、低、缺陷）的影响。此外，CAR.CIK 条件培养基能够上调黑色素瘤细胞上 HLA-I 分子的表达。用外源性 IFN-γ 和 IFN-α 处理 Mel 细胞可复制类似的免疫调节作用。在免疫缺陷小鼠中，CSPG4-CAR.CIK 对 HLA 缺陷性 Mel 异种移植物的生长抑制作用显著，体内证实了其抗黑色素瘤活性。
在这项研究中，我们报告了 CSPG4-CAR.CIK 对黑色素瘤的强烈临床前活性，包括那些 HLA-I 表达低或缺陷的黑色素瘤。我们的发现支持 CSPG4 作为黑色素瘤中一种有价值的 CAR 靶点，并为探索 CAR-CIK 细胞免疫疗法在对免疫检查点抑制剂无反应或复发的患者中具有挑战性的环境中的临床研究提供了转化依据。
