A genetically encoded multifunctional TRAIL trimer facilitates cell-specific targeting and tumor cell killing.
A genetically encoded multifunctional TRAIL trimer facilitates cell-specific targeting and tumor cell killing.
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DOI：
10.1158/1535-7163.mct-10-0225
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发表时间：
2010-07
影响因子：
5.7
通讯作者：
Hawkins WG
中科院分区：
文献类型：
--
作者：
Spitzer D;McDunn JE;Plambeck-Suess S;Goedegebuure PS;Hotchkiss RS;Hawkins WG
肿瘤坏死因子相关凋亡诱导配体（TRAIL，Apo 2L）已被证明对肿瘤细胞表现出有效和特异性的凋亡活性。已经在患者中尝试了几种TRAIL构建体，并且该分子仍处于积极的临床研究中。天然和重组TRAIL必须形成同源三聚体才能具有生物活性。然而，非共价结合的TRAIL显示出对降解的高度敏感性，这限制了其治疗潜力。为了加强重组蛋白的三聚化，我们通过基因融合开发了共价连接的TRAIL三聚体（TR 3）。这种分子药物设计赋予了改进的稳定性，而不改变TRAIL的天然杀伤能力。通过用可溶性死亡受体5（DR 5-Fc）阻断TR 3活性来证明靶特异性。此外，我们已经证明TR 3适合进一步的遗传修饰。向TR 3掺入额外的功能结构域，例如允许试剂的更细胞特异性递送的抗体片段（scFv），是化学计量控制的，并且对于TRAIL的生物活性无关紧要。作为概念验证，TR 3活性靶向小鼠RBC膜。TR 3修饰的RBC能够有效地杀死胰腺癌模型中的靶细胞。TR 3代表了一个普遍适用的平台工具，以研究死亡受体途径的基本机制沿着。更重要的是，将TR 3靶向细胞表面的能力提供了创造具有更少脱靶毒性和增强杀伤能力的癌症选择性药物的机会。
TNF-related apoptosis-inducing ligand (TRAIL, Apo2L) has been shown to exhibit potent and specific apoptotic activity against tumor cells. Several TRAIL constructs have been tried in patients and the molecule remains under active clinical investigation. Native and recombinant TRAIL must form a homotrimer to become biologically active. However, non-covalently associated TRAIL displays a high degree of sensitivity to degradation which limits its therapeutic potential. To enforce trimerization of the recombinant protein, we developed a covalently linked TRAIL trimer (TR3) by genetic fusion. This molecular drug design conferred improved stability without altering TRAIL's native killing ability. Target specificity was demonstrated by blocking TR3 activity with soluble death receptor 5 (DR5-Fc). In addition, we have demonstrated that TR3 is amenable to further, genetic modifications. The incorporation of additional functional domains to TR3, such as antibody fragments (scFvs) that allow for a more cell-specific delivery of the agent is stoichiometrically-controlled and inconsequential with regard to TRAIL's bioactivity. As a proof-of-concept, TR3 activity was targeted to the mouse RBC membrane. TR3-decorated RBCs were effectively capable of target cell killing in a model of pancreatic cancer. TR3 represents a generally applicable platform tool to study basic mechanisms along the death receptor pathway. More importantly, the ability to target TR3 to a cell surface presents the opportunity to create a cancer-selective drug with fewer off target toxicities and enhanced killing capacities.