Liu Xueting, Zeng Liping, Zhao Zhongqiu, Xie Yang, Wang Shan, Zhang Junyan, He Ying, Zou Zehong, Zhang Jianguo, Tao Ailin
1 The Second Affiliated Hospital, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, The State Key Laboratory of Respiratory Disease, Sino-French Hoffmann Institute, Guangzhou Medical University.
2 Center for the Study of Itch, Department of Anesthesiology, Washington University School of Medicine, St Louis, MO, USA.
Technol Cancer Res Treat. 2018 Jan 1;17:1533033818762910. doi: 10.1177/1533033818762910.
Staphylococcal enterotoxin A is well known as a superantigen and able to be used for cancer immunotherapy. In this study, recombinant Staphylococcal enterotoxin A was genetically conjugated to epidermal growth factor to produce a chimeric protein recombinant Staphylococcal enterotoxin A-epidermal growth factor expressed in Escherichia coli. The recombinant Staphylococcal enterotoxin A-epidermal growth factor protein was purified using Strep-Tactin affinity chromatography and Endotoxin Removal Resin and identified by sodium dodecyl sulfate-polyacrylamide gel electropheresis and liquid chromatography-tandem mass spectrometry analysis. Furthermore, in vitro experiments showed purified recombinant Staphylococcal enterotoxin A-epidermal growth factor could successfully bind to the human nasopharyngeal carcinoma cell line CNE2, significantly promote the proliferation of human peripheral blood mononuclear cells, and enhance the secretion of several cytokines that have broad antitumor activities, such as interferon-γ, tumor necrosis factor-α, and interleukin-2 . Importantly, recombinant Staphylococcal enterotoxin A-epidermal growth factor significantly inhibited proliferation of CNE2 cells and promoted apoptosis in CNE2 cells when cocultured with peripheral blood mononuclear cells. Finally, both the binding of recombinant Staphylococcal enterotoxin A-epidermal growth factor and the toxicity of recombinant Staphylococcal enterotoxin A-epidermal growth factor-activated peripheral blood mononuclear cells were demonstrated as specific and only effective on high epidermal growth factor receptor-expressing cell lines. In all, our work suggests that recombinant Staphylococcal enterotoxin A-epidermal growth factor serves as a promising novel immunotherapeutic agent. More in vivo and in vitro studies are needed to verify its antitumor potency, as well as investigate the underlying mechanisms in cancer immunotherapy.
葡萄球菌肠毒素A作为一种超抗原广为人知，可用于癌症免疫治疗。在本研究中，重组葡萄球菌肠毒素A与表皮生长因子进行基因偶联，以产生在大肠杆菌中表达的嵌合蛋白重组葡萄球菌肠毒素A-表皮生长因子。重组葡萄球菌肠毒素A-表皮生长因子蛋白通过链霉亲和素亲和层析和内毒素去除树脂进行纯化，并通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和液相色谱-串联质谱分析进行鉴定。此外，体外实验表明，纯化的重组葡萄球菌肠毒素A-表皮生长因子能够成功与人鼻咽癌细胞系CNE2结合，显著促进人外周血单个核细胞的增殖，并增强几种具有广泛抗肿瘤活性的细胞因子的分泌，如干扰素-γ、肿瘤坏死因子-α和白细胞介素-2。重要的是，重组葡萄球菌肠毒素A-表皮生长因子与外周血单个核细胞共培养时，显著抑制CNE2细胞的增殖并促进其凋亡。最后，重组葡萄球菌肠毒素A-表皮生长因子的结合以及重组葡萄球菌肠毒素A-表皮生长因子激活的外周血单个核细胞的毒性均表现为特异性，且仅对高表达表皮生长因子受体的细胞系有效。总之，我们的工作表明重组葡萄球菌肠毒素A-表皮生长因子是一种有前景的新型免疫治疗药物。需要更多的体内和体外研究来验证其抗肿瘤效力，并研究癌症免疫治疗的潜在机制。
