Centro Ricerca M. Tettamanti, Clinica Pediatrica, Ospedale San Gerardo, Università Milano-Bicocca, Monza, Italy.
J Immunother. 2011 Jul-Aug;34(6):469-79. doi: 10.1097/CJI.0b013e31821e763b.
The identification of the optimal T-cell effector subtype is a crucial issue for adoptive cell therapy with chimeric receptor-modified T cells. The ideal T cell population must be able to home toward tumor site, exert prolonged antitumoral activity, and display minimal toxicity against normal tissues. Therefore, we characterized the in vitro antitumoral properties of three effector T-cell populations: Epstein-Barr virus-specific cytotoxic T lymphocytes (EBV-CTLs), cytokine-induced killer (CIK) cells, and γ₉δ₂ T (GDT) cells, after transduction with a chimeric receptor specific for the CD33 antigen, broadly expressed on acute myeloid leukemia cells. EBV-CTLs, CIK, and GDT cells were generated and transduced with high efficiency with a retroviral vector coding for an anti-CD33-ζ chimeric receptor without alterations of their native phenotype. Anti-CD33-ζ chimeric receptor-redirected T cells displayed analogous in vitro chemotactic activity toward CXCL12. In addition, anti-CD33-ζ chimeric receptor-expressing EBV-CTLs, CIK, and GDT cells showed potent and similar cytotoxicity against several CD33⁺ leukemic targets both in short-term 4-hours-⁵¹chromium-release assays (mean killing vs primary leukemic cells at effector:target ratio of 5:1; 50%, 61%, and 50% for EBV-CTLs, CIK, and GDT cells, respectively) and in long-term assays, where they were cocultured with leukemic cells for 6 days on stromal mesenchymal cells (mean survival of primary leukemic cells at effector:target ratio of 1:100; 18%, 16%, and 29% for EBV-CTLs, CIK, and GDT cells, respectively). Moreover, all effector cells acquired consistent capability to proliferate in vitro after contact with CD33⁺ cells and to release high and comparable levels of immunostimulatory cytokines, while secreting similar low amount of immunoregulatory cytokines as the unmanipulated counterpart. Our results indicate that expression of an anti-CD33-ζ chimeric receptor potently and similarly increase the antileukemic functions of different effector T-cell subtypes, underlying the impossibility to identify a more potent T-cell population through in vitro analysis, and consistently with recent observations that have emerged from clinical trials with chimeric receptor-modified T cells, suggesting the need to perform such type of studies in the human setting.
嵌合抗原受体修饰 T 细胞过继细胞治疗中，鉴定最佳 T 细胞效应子亚型是一个关键问题。理想的 T 细胞群体必须能够向肿瘤部位归巢，发挥持久的抗肿瘤活性，并对正常组织表现出最小的毒性。因此，我们在体外对三种效应 T 细胞群体的抗肿瘤特性进行了表征：EBV-CTLs、CIK 细胞和γ₉δ₂ T（GDT）细胞，这些细胞在转导了一种针对广泛表达于急性髓系白血病细胞上的 CD33 抗原的嵌合受体后。EBV-CTLs、CIK 和 GDT 细胞以高效率被逆转录病毒载体转导，该载体编码一种抗 CD33-ζ 嵌合受体，而不会改变其天然表型。抗 CD33-ζ 嵌合受体导向的 T 细胞显示出对 CXCL12 的类似体外趋化活性。此外，表达抗 CD33-ζ 嵌合受体的 EBV-CTLs、CIK 和 GDT 细胞对几种 CD33+白血病靶标表现出强大且相似的细胞毒性，无论是在 4 小时-51Cr 释放试验中的短期试验（效应物：靶标比为 5:1 时的平均杀伤率；50%、61%和 50%分别为 EBV-CTLs、CIK 和 GDT 细胞）还是在长期试验中，其中它们与白血病细胞在基质间充质细胞上共培养 6 天（效应物：靶标比为 1:100 时的原代白血病细胞的平均存活率；50%、61%和 50%分别为 EBV-CTLs、CIK 和 GDT 细胞）。此外，所有效应细胞在与 CD33+细胞接触后均获得了一致的体外增殖能力，并释放出高且相当水平的免疫刺激性细胞因子，同时分泌出与未经处理的对应物相似的低量免疫调节细胞因子。我们的结果表明，表达抗 CD33-ζ 嵌合受体可强力且相似地增强不同效应 T 细胞亚型的抗白血病功能，这表明通过体外分析无法鉴定出更有效的 T 细胞群体，并且与最近从嵌合受体修饰 T 细胞的临床试验中出现的观察结果一致，这表明需要在人体环境中进行此类研究。
