Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control, No. 2, Tiantan Xili, Dongcheng District, Beijing, 100050, China.
Anal Bioanal Chem. 2018 Nov;410(27):7067-7075. doi: 10.1007/s00216-018-1307-0. Epub 2018 Sep 4.
IL-6 has an important role in the pathogenesis of autoimmunity and chronic inflammation. Several mAbs that target IL-6 or the IL-6 receptor (IL-6R) have been established and approved for the treatment of various diseases such as multicentric Castleman's disease and rheumatoid arthritis. Quality control of therapeutic antibodies requires accurate determination of bioactivity. However, current cell-based anti-proliferation assays are tedious, time consuming, and result in high variation. We therefore developed a reporter gene assay (RGA) based on an IL-6-dependent DS-1 cell line that stably expressed the reporter luciferase controlled by the serum-induced element (SIE) response element, which was a key element located downstream of the IL-6 signaling pathway. The RGA method demonstrated good performance characteristics after careful optimization, including high specificity, stability, accuracy, precision, and robustness. It also had superior precision and sensitivity. The assay is simple compared with the traditional anti-proliferation assay. This novel RGA based on the IL-6-IL-6R-STAT3 pathway can be useful, in conjunction with the anti-proliferation bioassay, to determine the bioactivity of anti-IL-6/anti-IL-6R therapeutic mAbs. Graphical abstract The mechanism sketch of the reporter gene assay for the bioactivity determination of anti-IL-6/anti-IL-6Rα mAbs.
IL-6 在自身免疫和慢性炎症的发病机制中起着重要作用。已经开发并批准了几种针对 IL-6 或 IL-6 受体 (IL-6R) 的 mAb 用于治疗多种疾病，如多发性骨髓瘤性 Castleman 病和类风湿关节炎。治疗性抗体的质量控制需要准确测定生物活性。然而，目前基于细胞的抗增殖测定既繁琐又耗时，且结果差异较大。因此，我们开发了一种基于依赖 IL-6 的 DS-1 细胞系的报告基因测定法 (RGA)，该细胞系稳定表达受血清诱导元件 (SIE) 反应元件控制的报告基因荧光素酶，这是 IL-6 信号通路下游的关键元件。经过仔细优化，RGA 方法表现出良好的性能特征，包括高特异性、稳定性、准确性、精密度和稳健性。它还具有更高的精度和灵敏度。与传统的抗增殖测定相比，该测定法较为简单。这种基于 IL-6-IL-6R-STAT3 通路的新型 RGA 可与抗增殖生物测定法结合使用，用于测定抗 IL-6/抗 IL-6R 治疗性 mAb 的生物活性。
