Generation of a novel fusion protein to redirect macrophage differentiation following radiation therapy.

 描述（由申请人提供）：放射治疗是杀死癌细胞的高效方式，并且我们和其他人已经证明，放射后的抗原佐剂释放可以产生和增强适应性免疫应答，特别是当与免疫调节治疗一起使用时。然而，这些作用受到辐射肿瘤中的肿瘤相关巨噬细胞的限制，所述巨噬细胞响应于与直接对抗抗肿瘤免疫应答的辐射细胞的相互作用而指导组织修复。我们建议靶向一个特定的途径，指导这种修复表型在巨噬细胞辐射后使用一种新的表型。我们假设，巨噬细胞对辐射的免疫反应可以被重定向远离修复表型，并朝向适应性促进免疫反应，使用一种新的Gas 6-CD 40 L融合蛋白。在这项研究中，我们建议进行这种新的融合蛋白的初步表征。为此，我们建议实现以下具体目标。目的1：表征Gas 6-CD 40 L融合蛋白与垂死细胞的体外结合及其激活巨噬细胞的能力。目的2：确定Gas 6-CD 40 L融合蛋白在无肿瘤和荷瘤小鼠中的体内药代动力学和毒性特征。目的3：测试Gas 6-CD 40 L融合蛋白在荷瘤小鼠中局灶性辐射后对肿瘤相关巨噬细胞的体内功能。我们的研究设计结合了融合蛋白结合的体外表征和对巨噬细胞极化的影响以及体内药代动力学、毒性和生物分布的研究。该项目的成功完成将为进一步开展更广泛的研究提供必要的初步数据和可行性。

 DESCRIPTION (provided by applicant): Radiation therapy is a highly effective modality to kill cancer cells, and we and others have demonstrated that both antigen adjuvant release following radiation can generate and enhance adaptive immune responses particularly when used with immunomodulatory therapies. However these effects are limited by tumor associated macrophages in the radiated tumor that direct tissue repair in response to interaction with irradiated cells that directly oppose anti-tumor immune responses. We propose targeting a specific pathway that directs this repair phenotype in macrophages following radiation using a novel phenotype. We hypothesize that the macrophage immune response to radiation can be redirected away from a repair phenotype and toward an adaptive promoting immune response using a novel Gas6-CD40L fusion protein. We propose in this study to perform initial characterization of this novel fusion protein. To do this we propose addressing the following specific aims. Aim1: Characterize the in vitro binding of a Gas6-CD40L fusion protein to dying cells and its ability to activate macrophages. Aim2: Define both the in vivo pharmacokinetic and toxicity profile of a Gas6-CD40L fusion protein in both tumor free and tumor bearing mice. Aim3: Test the in vivo function of a Gas6-CD40L fusion protein on tumor associated macrophages following focal radiation in tumor bearing mice. Our study design incorporates in vitro characterization of fusion protein binding and effect on macrophage polarization as well as in vivo studies of pharmacokinetics, toxicity and biodistribution. The successful completion of this project will provide the necessary preliminary data and feasibility for further development in more extensive studies.