Riggs Jeffrey M, Hanna Richard N, Rajan Bhargavi, Zerrouki Kamelia, Karnell Jodi L, Sagar Divya, Vainshtein Inna, Farmer Erika, Rosenthal Kimberly, Morehouse Chris, de Los Reyes Melissa, Schifferli Kevin, Liang Meina, Sanjuan Miguel A, Sims Gary P, Kolbeck Roland
Respiratory, Inflammation and Autoimmunity, MedImmune LLC, Gaithersburg, Maryland, USA.
Clinical Pharmacology and DMPK, MedImmune LLC, Mountain View, California, USA.
Lupus Sci Med. 2018 Apr 5;5(1):e000261. doi: 10.1136/lupus-2018-000261. eCollection 2018.
We investigated the mechanistic and pharmacological properties of anifrolumab, a fully human, effector-null, anti-type I interferon (IFN) alpha receptor 1 (IFNAR1) monoclonal antibody in development for SLE.
IFNAR1 surface expression and internalisation on human monocytes before and after exposure to anifrolumab were assessed using confocal microscopy and flow cytometry. The effects of anifrolumab on type I IFN pathway activation were assessed using signal transducer and activator of transcription 1 (STAT1) phosphorylation, IFN-stimulated response element-luciferase reporter cell assays and type I IFN gene signature induction. The ability of anifrolumab to inhibit plasmacytoid dendritic cell (pDC) function and plasma cell differentiation was assessed by flow cytometry and ELISA. Effector-null properties of anifrolumab were assessed in antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) assays with B cells.
Anifrolumab reduced cell surface IFNAR1 by eliciting IFNAR1 internalisation. Anifrolumab blocked type I IFN-dependent STAT1 phosphorylation and IFN-dependent signalling induced by recombinant and pDC-derived type I IFNs and serum of patients with SLE. Anifrolumab suppressed type I IFN production by blocking the type I IFN autoamplification loop and inhibited proinflammatory cytokine induction and the upregulation of costimulatory molecules on stimulated pDCs. Blockade of IFNAR1 suppressed plasma cell differentiation in pDC/B cell co-cultures. Anifrolumab did not exhibit CDC or ADCC activity.
Anifrolumab potently inhibits type I IFN-dependent signalling, including the type I IFN autoamplification loop, and is a promising therapeutic for patients with SLE and other diseases that exhibit chronic dysfunctional type I IFN signalling.
我们研究了阿尼鲁单抗的作用机制和药理学特性，这是一种正在研发用于系统性红斑狼疮（SLE）的全人源、无效应功能、抗I型干扰素（IFN）α受体1（IFNAR1）单克隆抗体。
使用共聚焦显微镜和流式细胞术评估人单核细胞在暴露于阿尼鲁单抗前后IFNAR1的表面表达和内化情况。使用信号转导和转录激活因子1（STAT1）磷酸化、IFN刺激反应元件荧光素酶报告基因细胞测定以及I型IFN基因特征诱导来评估阿尼鲁单抗对I型IFN通路激活的影响。通过流式细胞术和酶联免疫吸附测定（ELISA）评估阿尼鲁单抗抑制浆细胞样树突状细胞（pDC）功能和浆细胞分化的能力。在针对B细胞的抗体依赖性细胞介导的细胞毒性（ADCC）和补体依赖性细胞毒性（CDC）测定中评估阿尼鲁单抗的无效应功能特性。
阿尼鲁单抗通过引发IFNAR1内化降低细胞表面IFNAR1。阿尼鲁单抗阻断重组和pDC来源的I型IFN以及SLE患者血清诱导的I型IFN依赖性STAT1磷酸化和IFN依赖性信号传导。阿尼鲁单抗通过阻断I型IFN自身扩增环抑制I型IFN产生，并抑制促炎细胞因子诱导以及刺激的pDC上共刺激分子的上调。阻断IFNAR1抑制pDC/ B细胞共培养中的浆细胞分化。阿尼鲁单抗未表现出CDC或ADCC活性。
阿尼鲁单抗有效抑制I型IFN依赖性信号传导，包括I型IFN自身扩增环，对于SLE患者以及其他表现出慢性功能失调的I型IFN信号传导的疾病是一种有前景的治疗方法。
