Mazorra Zaima, Lavastida Anabel, Concha-Benavente Fernando, Valdés Anet, Srivastava Raghvendra M, García-Bates Tatiana M, Hechavarría Esperanza, González Zuyen, González Amnely, Lugiollo Martha, Cuevas Iván, Frómeta Carlos, Mestre Braulio F, Barroso Maria C, Crombet Tania, Ferris Robert L
Department of Clinical Immunology, Clinical Direction, Center of Molecular ImmunologyHavana, Cuba.
Department of Immunology, University of Pittsburgh, PittsburghPA, United States.
Front Pharmacol. 2017 Jun 19;8:382. doi: 10.3389/fphar.2017.00382. eCollection 2017.
Survival benefit and long-term duration of clinical response have been seen using the epidermal growth factor receptor (EGFR)-targeted monoclonal antibody (mAb) nimotuzumab. Blocking EGFR signaling may not be the only mechanism of action underlying its efficacy. As an IgG1 isotype mAb, nimotuzumab's capacity of killing tumor cells by antibody dependent cellular cytotoxicity (ADCC) and to induce an immune response in cancer patients have not been studied. ADCC-induced by nimotuzumab was determined using a Cr release assay. The effect of nimotuzumab on natural killer (NK) cell activation and dendritic cell (DC) maturation and the frequency of circulating regulatory T cells (Tregs) and NK cells were assessed by flow cytometry. Cytokine levels in supernatants were determined by ELISA. ELISpot was carried out to quantify EGFR-specific T cells in nimotuzumab-treated head and neck cancer (HNSCC) patients. Nimotuzumab was able to kill EGFR+ tumor cells by NK cell-mediated ADCC. Nimotuzumab-activated NK cells promoted DC maturation and EGFR-specific CD8+ T cell priming. Interestingly, nimotuzumab led to upregulation of some immune checkpoint molecules on NK cells (TIM-3) and DC (PD-L1), to a lower extent than another EGFR mAb, cetuximab. Furthermore, circulating EGFR-specific T cells were identified in nimotuzumab-treated HNSCC patients. Notably, nimotuzumab combined with cisplatin-based chemotherapy and radiation increased the frequency of peripheral CD4+CD39+FOXP3+Tregs which otherwise were decreased to baseline values when nimotuzumab was used as monotherapy. The frequency of circulating NK cells remained constant during treatment. Nimotuzumab-induced, NK cell-mediated DC priming led to induction of anti-EGFR specific T cells in HNSCC patients. The association between EGFR-specific T cells and patient clinical benefit with nimotuzumab treatment should be investigated.
使用表皮生长因子受体（EGFR）靶向单克隆抗体（mAb）尼妥珠单抗已观察到生存获益和临床反应的长期持续时间。阻断EGFR信号传导可能不是其疗效的唯一作用机制。作为一种IgG1同种型单克隆抗体，尼妥珠单抗通过抗体依赖性细胞毒性（ADCC）杀伤肿瘤细胞的能力以及在癌症患者中诱导免疫反应的能力尚未得到研究。使用铬释放试验确定尼妥珠单抗诱导的ADCC。通过流式细胞术评估尼妥珠单抗对自然杀伤（NK）细胞活化、树突状细胞（DC）成熟以及循环调节性T细胞（Tregs）和NK细胞频率的影响。通过酶联免疫吸附测定（ELISA）确定上清液中的细胞因子水平。进行酶联免疫斑点试验（ELISpot）以量化尼妥珠单抗治疗的头颈癌（HNSCC）患者中EGFR特异性T细胞。尼妥珠单抗能够通过NK细胞介导的ADCC杀伤EGFR+肿瘤细胞。尼妥珠单抗激活的NK细胞促进DC成熟和EGFR特异性CD8+T细胞致敏。有趣的是，尼妥珠单抗导致NK细胞（TIM-3）和DC（PD-L1）上一些免疫检查点分子的上调，其程度低于另一种EGFR单克隆抗体西妥昔单抗。此外，在尼妥珠单抗治疗的HNSCC患者中鉴定出循环EGFR特异性T细胞。值得注意的是，尼妥珠单抗与基于顺铂的化疗和放疗联合使用增加了外周CD4+CD39+FOXP3+Tregs的频率，而当尼妥珠单抗作为单一疗法使用时，这些细胞会降至基线值。治疗期间循环NK细胞的频率保持恒定。尼妥珠单抗诱导的、NK细胞介导的DC致敏导致HNSCC患者中抗EGFR特异性T细胞的诱导。应研究EGFR特异性T细胞与尼妥珠单抗治疗患者临床获益之间的关联。
