Generation and Selection of Novel Fully Human Monoclonal Antibodies That Neutralize Dickkopf-1 (DKK1) Inhibitory Function in Vitro and Increase Bone Mass in Vivo
Generation and Selection of Novel Fully Human Monoclonal Antibodies That Neutralize Dickkopf-1 (DKK1) Inhibitory Function in Vitro and Increase Bone Mass in Vivo
复制标题
DOI：
10.1074/jbc.m110.166892
复制
发表时间：
2010-12-17
影响因子：
4.8
通讯作者：
Wang, Fubao
中科院分区：
文献类型：
--
作者：
Glantschnig, Helmut;Hampton, Richard A.;Wang, Fubao
Wnt/LRP 5信号传导是骨形成和骨吸收活性的中心调节组分，并且通路抑制剂DKK 1是小鼠中骨形成和骨量增加的抑制剂。此外，增加的DKK 1水平与啮齿动物模型中各种低骨量状态下的高骨转换和人类疾病病因相关。然而，检查DKK 1在正常骨骼和高等物种中的确切作用需要开发精制的DKK 1特异性药理学工具。在这里，我们报告的策略，导致在一个小组的完全人抗DKK 1抗体适用于研究的作用，小鼠，恒河猴，和人类DKK 1的质疑隔离。选择的抗DKK 1抗体以皮摩尔亲和力结合灵长类动物和人DKK-1，但不明显结合DKK 2或DKK 4。表位定位在DKK 1 C-末端结构域内，是与LRP 5/6相互作用所必需的，因此在体外有效地中和DKK 1功能。当引入到幼稚的正常生长的雌性小鼠，IgG显着改善骨小梁的体积和结构，并增加骨小梁和皮质骨矿物质密度以剂量相关的方式。此外，全人DKK 1-IgG在非人灵长类动物中显示出有利的药代动力学参数。总之，我们在此证明了生理DKK 1水平在调节完整雌性小鼠骨量中的限速功能，可通过新鉴定的DKK 1-IgG进行特异性药理学中和。重要的是，全人源IgG显示出一系列属性，这些属性建议在高等物种中进行测试，并在相关疾病模型中评估DKK 1功能。
Wnt/LRP5 signaling is a central regulatory component of bone formative and resorptive activities, and the pathway inhibitor DKK1 is a suppressor of bone formation and bone mass accrual in mice. In addition, augmented DKK1 levels are associated with high bone turnover in diverse low bone mass states in rodent models and disease etiologies in human. However, examination of the precise role of DKK1 in the normal skeleton and in higher species requires the development of refined DKK1-specific pharmacological tools. Here, we report the strategy resulting in isolation of a panel of fully human anti-DKK1 antibodies applicable to studies interrogating the roles of mouse, rhesus, and human DKK1. Selected anti-DKK1 antibodies bind primate and human DKK-1 with picomolar affinities yet do not appreciably bind to DKK2 or DKK4. Epitopes mapped within the DKK1 C-terminal domain necessary for interaction with LRP5/6 and consequently effectively neutralized DKK1 function in vitro. When introduced into naive normal growing female mice, IgGs significantly improved trabecular bone volume and structure and increased both trabecular and cortical bone mineral densities in a dose-related fashion. Furthermore, fully human DKK1-IgG displayed favorable pharmacokinetic parameters in non-human primates. In summary, we demonstrate here a rate-limiting function of physiologic DKK1 levels in the regulation of bone mass in intact female mice, amendable to specific pharmacologic neutralization by newly identified DKK1-IgGs. Importantly the fully human IgGs display a profile of attributes that recommends their testing in higher species and their use in evaluating DKK1 function in relevant disease models.