Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Japan.
Institute for Molecular Science (IMS), National Institutes of Natural Sciences, Okazaki, Japan.
Front Immunol. 2023 Jan 25;14:1090898. doi: 10.3389/fimmu.2023.1090898. eCollection 2023.
Although interactions of small molecular drugs with serum proteins have been widely studied from pharmacokinetic and pharmacodynamic perspectives, there have been few reports on the effects of serum components on therapeutic antibody functions. This study reports the effect of abundant serum proteins on antibody-dependent cellular cytotoxicity (ADCC) mediated by rituximab and Fcγ receptor III (FcγRIII). Human serum albumin (HSA) and the Fab fragment from the pooled serum polyclonal IgG were found to compromise ADCC as non-competitive inhibitors. Our nuclear magnetic resonance data provided direct evidence for the interactions of HSA with both the Fab and Fc regions of rituximab and also with the extracellular region of FcγRIII (sFcγRIII). The degree of involvement in the interaction decreased in the order of rituximab-Fab > rituximab-Fc > sFcγRIII, suggesting preferential binding of HSA to net positively charged proteins. Although much less pronounced than the effect of HSA, polyclonal IgG-Fab specifically interacted with rituximab-Fc. The NMR data also showed that the serum protein interactions cover the Fc surface extensively, suggesting that they can act as pan-inhibitors against various Fc receptor-mediated functions and pharmacokinetics. Our findings highlight the importance of considering serum-protein interactions in the design and application of antibody-based drugs with increased efficacy and safety.
虽然小分子药物与血清蛋白的相互作用已从药代动力学和药效学的角度进行了广泛研究，但关于血清成分对治疗性抗体功能的影响的报道却很少。本研究报告了丰富的血清蛋白对利妥昔单抗和 Fcγ 受体 III（FcγRIII）介导的抗体依赖的细胞毒性（ADCC）的影响。人血清白蛋白（HSA）和来自混合血清多克隆 IgG 的 Fab 片段被发现作为非竞争性抑制剂来降低 ADCC。我们的核磁共振数据为 HSA 与利妥昔单抗的 Fab 和 Fc 区域以及 FcγRIII 的细胞外区域（sFcγRIII）相互作用提供了直接证据。相互作用的参与程度按利妥昔单抗-Fab > 利妥昔单抗-Fc > sFcγRIII 的顺序降低，表明 HSA 优先与带净正电荷的蛋白质结合。尽管不如 HSA 的影响明显，但多克隆 IgG-Fab 特异性地与利妥昔单抗-Fc 相互作用。NMR 数据还表明，血清蛋白相互作用广泛覆盖 Fc 表面，表明它们可以作为针对各种 Fc 受体介导的功能和药代动力学的泛抑制剂。我们的发现强调了在设计和应用具有更高疗效和安全性的抗体药物时考虑血清蛋白相互作用的重要性。
