Development of novel targeted degradation strategies to modulate immunosuppressive adenosine signaling in cancer

开发新型靶向降解策略来调节癌症中的免疫抑制腺苷信号传导

基本信息

批准号：
10312522
负责人：
Katarina Pance
金额：
$ 1.85万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2021-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10312522
关键词：
Address Adenosine Agonist Antibodies Antibody-drug conjugates Antineoplastic Agents Binding Binding Proteins Biological Biological Models Bispecific Antibodies CD8-Positive T-Lymphocytes Cancer cell line Cell Line Cell Surface Proteins Cell surface Cells Chemicals Clinical Treatment Clinical Trials Data Development Dose Drug Approval Endosomes Engineering Epitopes Event Extracellular Protein Future G-Protein-Coupled Receptors Generations Goals Half-Life Human Immune Immune response Immunoglobulin G Interleukin 2 Receptor Interleukin-2 Lead Length Ligands Link Malignant Neoplasms Mediating Membrane Membrane Proteins Methods Modality Modeling Monoclonal Antibodies Patients Phage Display Pharmaceutical Preparations Pharmacology Polyubiquitination Property Protac Proteins Proteome Recombinant Antibody Regulatory T-Lymphocyte Research Signal Pathway Signal Transduction Site T-Lymphocyte Technology Testing Therapeutic Therapeutic Effect Toxic effect Treatment Efficacy Ubiquitin Ubiquitination base cancer therapy cell type clinically relevant experimental study extracellular immune checkpoint improved inhibitor/antagonist insight interest member multicatalytic endopeptidase complex new technology non-Native novel programmed cell death ligand 1 protein degradation receptor receptor binding receptor internalization recruit resistance mechanism scaffold small molecule success targeted delivery therapeutic protein treatment strategy tumor ubiquitin-protein ligase

项目摘要

Project Summary Small molecule and biologic drugs have dominated FDA cancer drug approvals over the last two decades. However, due to their occupancy-driven pharmacology, these therapies are generally liable to cancer resistance mechanisms. Thus, there remains a critical need for the development of novel cancer therapeutics to improve treatment efficacy and patient survival. Recently, heterobifunctional small molecule protein degraders which operate through event-driven pharmacology have emerged as an alternative cancer treatment strategy. These modalities, such as PROteolysis TArgeting Chimeras (PROTACs), have been successful in recruiting E3 ubiquitin ligases to non-native substrates, leading to the ubiquitination and proteasomal degradation of the target protein. However, recruitment of intracellular E3 ligases inherently limits the target scope of PROTACs to intracellular proteins. To counteract this limitation, our lab has recently developed a strategy termed antibody- based PROTACs (AbTACs), which are bispecific antibody constructs that recruit membrane-bound E3 ligase, RNF43, to a cell surface protein of interest for efficient lysosomal degradation. Though successful, some limitations to our approach currently exist. Namely, (1) we are unable to degrade multi-pass membrane proteins for which few extracellular-binding antibodies exist and (2) the ubiquitous expression of RNF43 limits cell-type selective degradation. To this end, I hypothesize that antibody-drug conjugates will enable targeting of multi- pass membrane proteins for E3 ligase-mediated degradation. Furthermore, I hypothesize that non-E3 ligases, such as rapidly internalizing receptors, can be co-opted for cell-type selective targeting. Here, I propose to expand the scope of AbTACs to overcome these limitations and modulate the immunosuppressive adenosine signaling pathway in human cancers through the development of two novel antibody-based modalities. First, I have developed antibody-drug conjugates that comprise of an anti-RNF43 antibody chemically linked to a small molecule adenosine 2a receptor (A2aR) agonist. I have confirmed the degradation ability of these first-generation A2aR degraders in a MOLT-4 derived T cell line and shown dose-, site-, and linker-length dependent degradation of A2aR. Going forward, I will optimize the antibody-drug conjugate to confer maximal A2aR degradation, which will then be used to characterize the mechanism and functional consequences of degradation on boosting CD8+ T cell immune response. To develop T regulatory cell (Treg)-selective degraders of adenosine-generating CD39 and CD73, I will perform phage display on interleukin-2 receptor α (IL-2Rα) to isolate antibodies that bind outside the IL-2 epitope. I will engineer these binders into bispecific knob-in-hole antibodies, which I expect to efficiently degrade CD39 and CD73 upon IL-2 stimulation and IL-2Rα internalization. Finally, I will functionally characterize CD39/CD73 degradation to determine its effect on inhibiting Treg-generated immunosuppressive adenosine. Collectively, the proposed studies will lead to the development of two novel targeted degradation modalities and provide mechanistic insights into the functional consequences of degrading A2aR, CD39, and CD73.

项目摘要在过去的二十年中，小分子和生物药在FDA癌症药物批准中占主导地位。但是，由于其占用驱动的药理学，这些疗法通常容易受到抗癌的耐药性机制。这仍然是开发新型癌症治疗以改善的迫切需要治疗效率和患者生存。最近，杂功能的小分子蛋白降解剂通过事件驱动的药理学运作已成为替代性癌症治疗策略。这些靶向嵌合体的蛋白水解（Protacs）等模态已成功地招募E3 泛素连接酶至非本地底物，导致靶标的泛素化和蛋白酶体降解蛋白质。但是，募集细胞内E3连接酶固有地将Protac的目标范围限制为细胞内蛋白。为了抵消这一限制，我们的实验室最近制定了一种称为抗体 - 的策略基于双特异性抗体构建体的基于膜结合的E3连接酶的双特异性抗体构建体（ABTAC） RNF43，到具有有效溶酶体降解的感兴趣的细胞表面蛋白。虽然成功，有些目前存在对我们方法的局限性。即，（1）我们无法降解多通膜蛋白对于几乎没有细胞外结合抗体的存在，（2）RNF43的无处不在表达限制了细胞类型选择性降解。为此，我假设抗体 - 药物结合物将能够靶向多通过E3连接酶介导的降解的膜蛋白。此外，我假设非E3连接酶，例如快速内在化的受体可以选择用于细胞类型的选择性靶向。在这里，我建议扩大ABTAC的范围以克服这些局限性并调节免疫抑制腺苷通过开发两种新型抗体模态，人类癌症中的信号传导途径。首先，我已经开发了抗体 - 药物缀合物，该抗体的抗体抗体化学上的抗RNF43抗体与小分子腺苷2A受体（A2AR）激动剂。我已经确认了这些第一代的降解能力 Molt-4派生的T细胞系中的A2AR降解器，并显示剂量，位点和接头依赖性降解 A2ar。展望未来，我将优化对会议最大A2AR降解的抗体 - 药物结合物，然后将使用降解对增强CD8+的机理和功能后果表征 T细胞免疫响应。开发T调节细胞（TREG） - 生成CD39的选择性降解者和CD73，我将在白介素-2受体α（IL-2Rα）上执行噬菌体显示，以分离出在外部结合的抗体 IL-2情节。我将把这些粘合剂设计成双特异性旋钮抗体，我希望它能有效 IL-2模拟和IL-2Rα内在化后，降解CD39和CD73。最后，我将在功能上表征 CD39/CD73降解以确定其对抑制Treg生成的免疫抑制腺苷的影响。总体而言，拟议的研究将导致两种新颖的靶向降解方式的发展和提供有关降解A2AR，CD39和CD73的功能后果的机械见解。