Seliktar-Ofir Sivan, Merhavi-Shoham Efrat, Itzhaki Orit, Yunger Sharon, Markel Gal, Schachter Jacob, Besser Michal J
Ella Lemelbaum Institute for Immuno-Oncology, Sheba Medical Center, Tel Hashomer, Israel.
Department of Clinical Immunology and Microbiology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Front Immunol. 2017 Oct 10;8:1211. doi: 10.3389/fimmu.2017.01211. eCollection 2017.
Adoptive cell therapy (ACT) of autologous tumor infiltrating lymphocytes (TIL) is an effective immunotherapy for patients with solid tumors, yielding objective response rates of around 40% in refractory patients with metastatic melanoma. Most clinical centers utilize bulk, randomly isolated TIL from the tumor tissue for expansion and infusion. Only a minor fraction of the administered T cells recognizes tumor antigens, such as shared and mutation-derived neoantigens, and consequently eliminates the tumor. Thus, there are many ongoing effects to identify and select tumor-specific TIL for therapy; however, those approaches are very costly and require months, which is unreasonable for most metastatic patients. CD137 (4-1BB) has been identified as a co-stimulatory marker, which is induced upon the specific interaction of T cells with their target cell. Therefore, CD137 can be a useful biomarker and an important tool for the selection of tumor-reactive T cells. Here, we developed and validated a simple and time efficient method for the selection of CD137-expressing T cells for therapy based on magnetic bead separation. CD137 selection was performed with clinical grade compliant reagents, and TIL were expanded in a large-scale manner to meet cell numbers required for the patient setting in a GMP facility. For the first time, the methodology was designed to comply with both clinical needs and limitations, and its feasibility was assessed. CD137-selected TIL demonstrated significantly increased antitumor reactivity and were enriched for T cells recognizing neoantigens as well as shared tumor antigens. CD137-based selection enabled the enrichment of tumor-reactive T cells without the necessity of knowing the epitope specificity or the antigen type. The direct implementation of the CD137 separation method to the cell production of TIL may provide a simple way to improve the clinical efficiency of TIL ACT.
自体肿瘤浸润淋巴细胞（TIL）的过继性细胞疗法（ACT）是一种针对实体瘤患者的有效免疫疗法，在转移性黑色素瘤难治性患者中产生的客观缓解率约为40%。大多数临床中心利用从肿瘤组织中大量随机分离的TIL进行扩增和输注。所输注的T细胞中只有一小部分能识别肿瘤抗原，如共享抗原和突变衍生的新抗原，从而消除肿瘤。因此，目前有许多正在进行的研究致力于识别和选择用于治疗的肿瘤特异性TIL；然而，这些方法成本非常高，而且需要数月时间，这对大多数转移性患者来说是不合理的。CD137（4-1BB）已被确定为一种共刺激标志物，它在T细胞与其靶细胞的特异性相互作用时被诱导。因此，CD137可以成为一种有用的生物标志物以及选择肿瘤反应性T细胞的重要工具。在此，我们开发并验证了一种基于磁珠分离的简单且省时的方法，用于选择表达CD137的T细胞进行治疗。使用符合临床级标准的试剂进行CD137选择，并在GMP设施中大规模扩增TIL，以满足患者治疗所需的细胞数量。该方法首次被设计为既符合临床需求又考虑到局限性，并对其可行性进行了评估。经CD137选择的TIL显示出显著增强的抗肿瘤反应性，并且富集了识别新抗原以及共享肿瘤抗原的T细胞。基于CD137的选择能够富集肿瘤反应性T细胞，而无需了解表位特异性或抗原类型。将CD137分离方法直接应用于TIL的细胞生产可能提供一种提高TIL ACT临床效率的简单方法。
