Polarizing Macrophages to Tumor Suppressors by Blocking Multiple CCR2 Chemokine Receptor Epitopes

项目摘要 尽管肿瘤间质在癌症进展中起着重要作用，但绝大多数抗癌疗法都是在肿瘤细胞中进行的。 靶向癌细胞，而不是肿瘤微环境。一种新的药物递送方法，不仅靶向 肿瘤细胞以及炎性细胞将是高度期望的。在这里，我们建议开发一个交付 该平台建立在我们最近设计单链可变片段抗体的工作基础上， 炎性单核细胞迁移至肿瘤和巨噬细胞向杀肿瘤M1表型迁移 通过劫持CCL 2/CCR 2通路。这种方法利用了抗体结合特异性，但利用了 CCR 2受体的结构和功能，以提高治疗效果。我们假设同时 靶向多个CCR 2表位将介导协同药物效应并抑制肿瘤生长和转移 通过诱导M1巨噬细胞极化和减少巨噬细胞迁移。我们的蛋白质递送方法 利用抗体片段的靶向特异性以及它们诱导或修饰 下行信号。因此，抗体片段将同时充当递送载体和治疗药物 并且具有使载体诱导的毒性最小化的潜力。本提案的具体目标是：（1）综合 用于巨噬细胞极化的模块化CCR 2靶向zip-ligand系统，并建立其作用机制; (2)评估多表位CCR 2靶向构建体对巨噬细胞极化，肿瘤生长， 三阴性乳腺癌（TNBC）小鼠模型中的转移;和（3）评估治疗效果 多表位CCR 2靶向与（a）抗PD-1阻断剂和（B）其它治疗剂组合在小鼠中的应用 TNBC是一种临床结果特别差且治疗选择有限的亚型。一旦成功 完成后，该项目将建立一个新的交付概念，以修改下游信令和调制 细胞表型

Project Summary Despite the important role of the tumor stroma in cancer progression, the vast majority of anticancer therapies target cancer cells and not the tumor microenvironment. A novel drug delivery approach that not only target tumor cells but also the inflammatory cells would be highly desirable. Here we propose to develop a delivery platform that builds on our recent work designing single chain variable fragment antibodies that both inhibit inflammatory monocyte migration to tumors and polarize macrophages towards the tumoricidal M1 phenotype by hijacking the CCL2/CCR2 pathway. This approach capitalizes on antibody binding specificity but exploits CCR2 receptor structure and function to improve therapeutic efficacy. We hypothesize that simultaneous targeting of multiple CCR2 epitopes will mediate a synergistic drug effect and inhibit tumor growth and metastasis by inducing M1 macrophage polarization and reducing macrophage migration. Our protein delivery approach capitalizes on both the targeting specificity of antibody fragments and also their ability to induce or modify downstream signaling. Thus, the antibody fragments will serve both as a delivery vehicle and therapeutic drug and have the potential to minimize carrier-induced toxicity. The specific aims of this proposal are to (1) synthesize a modular CCR2-targeting zip-ligand system for macrophage polarization and establish its mechanism of action; (2) assess the effects of multi-epitope CCR2-targeting constructs on macrophage polarization, tumor growth, and metastasis in a triple-negative breast cancer (TNBC) mouse model; and (3) evaluate the therapeutic effects of multi-epitope CCR2 targeting in combination with (a) anti-PD-1 blockade and (b) other therapeutics in a mouse model of TNBC, a subtype with particularly poor clinical outcomes and limited treatment options. Upon successful completion, this project will establish a new delivery concept to modify downstream signaling and modulate cellular phenotypes.