Effector molecules of the apoptosis-inducing signaling cascade as active components in cytotoxic antibody fusion proteins for cancer therapy

细胞凋亡诱导信号级联的效应分子作为癌症治疗细胞毒性抗体融合蛋白的活性成分

• 批准号: 46199767
• 负责人: Professor Dr. Winfried Wels
• 金额: --
• 依托单位: Georg-Speyer-Haus, Institut für Tumorbiologie und experimentelle Therapie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/46199767?language=en
• 关键词: Effector; molecules; apoptosis; inducing; signaling

Major objective of this project is the generation of highly active, immunotoxin-like antibody fusion proteins, that utilize a cell-death inducing effector protein of human origin to eliminate tumor cells. The potential utility of immunotoxins for cancer therapy was demonstrated in clinical studies with recombinant molecules, that employ a bacterial toxin as a cytotoxic effector. However, these studies also identified the high immunogenicity of the bacterial protein domain as a critical limitation. We previously described prototypic, humanized antibody fusion proteins, that approach the high specificity and cell killing activity of current immunotoxins. Such molecules contain the human pro-apoptotic serine protease Granzyme B (GrB) as a cytotoxic effector, fused to cell recognition domains that bind to the clinically relevant tumor-associated antigens ErbB2 and EGF receptor. Based on such prototypic molecules, we will introduce well directed modifications intended to eliminate remaining nonspecific cell binding activity of the effector domain, and extend specific cell recognition to other important surface antigens on tumor cells such as CD20 and EpCAM. Furthermore, efficient release from endosomes after uptake, and intracellular routing to critical target substrates will be improved by including additional functional domains. To enhance antitumoral activity, individual modifications will be combined, and such optimized molecules will be tested in human tumor xenograft models in vivo. We expect that principles established during this project will not only result in tumor-specific GrB fusion proteins suitable for further development towards clinical applications, but will also provide a basis to improve immunotoxin-like reagents derived from other human pro-apoptotic molecules.

该项目的主要目标是产生高活性的免疫毒素样抗体融合蛋白，其利用人源性细胞死亡诱导效应蛋白来消除肿瘤细胞。免疫毒素用于癌症治疗的潜在效用在使用重组分子的临床研究中得到证实，所述重组分子采用细菌毒素作为细胞毒性效应物。然而，这些研究也确定了细菌蛋白结构域的高免疫原性作为关键限制。我们先前描述了原型、人源化抗体融合蛋白，其接近当前免疫毒素的高特异性和细胞杀伤活性。这些分子含有人促凋亡丝氨酸蛋白酶颗粒酶B（GrB）作为细胞毒性效应物，其融合到与临床相关的肿瘤相关抗原ErbB 2和EGF受体结合的细胞识别结构域。基于这样的原型分子，我们将引入良好的定向修饰，旨在消除效应结构域的剩余非特异性细胞结合活性，并将特异性细胞识别扩展到肿瘤细胞上的其他重要表面抗原，如CD20和EpCAM。此外，通过包括额外的功能结构域，将改善摄取后从内体的有效释放以及细胞内向关键靶底物的路由。为了增强抗肿瘤活性，将组合单独的修饰，并且将在体内人肿瘤异种移植模型中测试这种优化的分子。我们期望在该项目期间建立的原理不仅将导致肿瘤特异性GrB融合蛋白适合于进一步向临床应用发展，而且还将提供基础以改进来自其他人促凋亡分子的免疫毒素样试剂。