Effector-attenuating Substitutions That Maintain Antibody Stability and Reduce Toxicity in Mice
Effector-attenuating Substitutions That Maintain Antibody Stability and Reduce Toxicity in Mice
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DOI：
10.1074/jbc.m116.767749
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发表时间：
2017-03-03
影响因子：
4.8
通讯作者：
Ernst, James A.
中科院分区：
文献类型：
--
作者：
Lo, Megan;Kim, Hok Seon;Ernst, James A.
抗体 Fc 区调节抗体细胞毒活性和血清半衰期。然而，在治疗背景下，抗体的细胞毒性效应子功能通常是不理想的，并且可能通过激活针对表达受体抗原的细胞的天然宿主免疫防御而产生安全隐患。据报道，Fc 区的几种氨基酸变化可沉默或降低抗体的效应子功能。这些早期研究主要集中于人类抗体与人类 Fc 受体的相互作用，但目前仍不清楚 Fc 的这种变化如何转化为鼠抗体。我们证明常用的 N297G (NG) 和 D265A、N297G (DANG) 变体可有效减弱灵长类动物的效应子功能，但在小鼠中保留有效的补体激活能力，从而导致小鼠研究中的安全隐患。相比之下，我们发现 L234A、L235A、P329G (LALA-PG) 变体消除了鼠 IgG2a 和人 IgG1 中的补体结合和固定以及 Fc 依赖性、抗体依赖性、细胞介导的细胞毒性。这些 LALA-PG 取代可以在小鼠和灵长类动物之间更准确地翻译无效应抗体产生的结果。此外，我们还表明，含有 LALA-PG 变体的人类和鼠类抗体在啮齿类动物中都具有典型的药代动力学，并保留了热稳定性，从而实现了高效的旋钮入孔双特异性抗体生产，并为临床前研究提供了生成高度效应衰减的双特异性抗体的可靠途径。
The antibody Fc region regulates antibody cytotoxic activities and serum half-life. In a therapeutic context, however, the cytotoxic effector function of an antibody is often not desirable and can create safety liabilities by activating native host immune defenses against cells expressing the receptor antigens. Several amino acid changes in the Fc region have been reported to silence or reduce the effector function of antibodies. These earlier studies focused primarily on the interaction of human antibodies with human Fc- receptors, and it remains largely unknown how such changes to Fc might translate to the context of a murine antibody. We demonstrate that the commonly used N297G (NG) and D265A, N297G (DANG) variants that are efficacious in attenuating effector function in primates retain potent complement activation capacity in mice, leading to safety liabilities in murine studies. In contrast, we found an L234A, L235A, P329G (LALA-PG) variant that eliminates complement binding and fixation as well as Fc--dependent, antibody-dependent, cell-mediated cytotoxity in both murine IgG2a and human IgG1. These LALA-PG substitutions allow a more accurate translation of results generated with an effectorless antibody between mice and primates. Further, we show that both human and murine antibodies containing the LALA-PG variant have typical pharmacokinetics in rodents and retain thermostability, enabling efficient knobs-into-holes bispecific antibody production and a robust path to generating highly effector-attenuated bispecific antibodies for preclinical studies.