Biomaterials for Targeted Modulation of Conventional Type 1 Dendritic Cells

摘要 免疫疗法已经显示出治愈癌症的巨大希望，特别是随着检查站封锁的成功 和嵌合抗原受体(CAR)T细胞疗法，但其用途仍然受到患者应答率低的限制， 对许多实体肿瘤疗效不佳，和/或严重副作用。这些问题推动了 新的免疫疗法可以诱导强大和持久的细胞毒性T淋巴细胞(CTL)反应，并最大限度地减少 偏离目标的毒性。1型常规树突状细胞(CDC1s)的靶向调控 在抗原交叉呈递中，淋巴中的CTL反应将能够得到最佳的激活，并导致强大的 免疫疗法，但到目前为止还没有实现。这个项目的主要目标是开发一个大尺度的 将免疫细胞归巢大孔材料与代谢多糖相结合的材料体系 标记以实现体内cDC1的募集、标记和靶向。有了这个材料系统，我们的目标是开发 一种前所未有的免疫调节剂靶向偶联技术，包括抗原， 佐剂和细胞因子结合到淋巴结中的CDC1s，并进一步开发有效和安全的癌症免疫治疗。 为了实现这一点，一种可注射的大孔生物材料负载了cDC1-募集趋化因子和叠氮基- 糖将被用来在原位招募和代谢性地标记带有化学标记(例如叠氮基团)的cDC1。这些 化学标记的CDC1s可以从生物材料迁移到淋巴结，以进行随后的靶向结合 通过高效和生物正交点击化学的免疫调节剂。将组织实验 围绕三个目标。在目标1中，可注射造孔藻酸盐凝胶具有独立可调节的孔径、硬度 将制定粘度、趋化因子释放动力学，以及各参数对免疫功能的影响 将阐明细胞募集情况，以便合理设计能够 优先招募并在原位代谢标记叠氮基团的cDC1s。在目标2中，靶向递送肿瘤 通过点击化学方法将新抗原和佐剂或脂质体疫苗转移到淋巴结中叠氮标记的CDC1s 正在探索，目标是改善新抗原特异性CTL反应和整体抗肿瘤疗效 对抗免疫原性差的实体瘤。在目标3中，靶向接合和表面展示 将探索淋巴组织中CDC1s的免疫调节剂，以调节CDC1T细胞之间的相互作用 放大CTL反应。我们假设，细胞因子一旦结合，可以保留在cDC1表面 在T细胞启动过程中为效应T细胞提供持续刺激的时间。完成 该项目将导致新的免疫疗法，具有强大的抗肿瘤效果，对实体瘤和减少 偏离目标的副作用。此外，cdc1的招募、标记和定向技术也将在 自身免疫性疾病和传染病治疗的未来发展。

SUMMARY Immunotherapy has shown great promise to cure cancers, especially with the success of checkpoint blockades and chimeric antigen receptor (CAR) T cell therapies, but its utility is still limited by low patient response rate, poor efficacy against many solid tumors, and/or severe side effects. These issues motivate the development of new immunotherapy that can elicit potent and persistent cytotoxic T lymphocyte (CTL) responses and minimize off-target toxicity. Targeted modulation of type 1 conventional dendritic cells (cDC1s), a subset of DCs superior in antigen cross-presentation, in lymph nodes will enable optimal activation of CTL responses and result in robust immunotherapy, but has not been achieved so far. The primary goal of this project is to develop a macroscale materials-based system that integrates immune cell-homing macroporous materials with metabolic glycan labeling to achieve cDC1 recruitment, labeling, and targeting in vivo. With this material system, we aim to develop an unprecedented technology for targeted conjugation of immunomodulatory agents, including antigens, adjuvants, and cytokines, to cDC1s in lymph nodes, and further develop potent and safe cancer immunotherapy. To achieve this, an injectable macroporous biomaterial loaded with cDC1-recruiting chemokines and azido- sugars will be used to recruit and metabolically label cDC1s with chemical tags (e.g., azido group) in situ. These chemically tagged cDC1s can migrate from the biomaterial to lymph nodes for subsequent targeted conjugation of immunomodulatory agents via efficient and bioorthogonal click chemistry. Experiments will be organized around three aims. In Aim 1, injectable pore-forming alginate gels with independently tunable pore size, stiffness, viscosity, and chemokine release kinetics will be developed, and the impact of each parameter on the immune cell recruitment profile will be elucidated, in order to rationally design macroporous materials that can preferentially recruit and metabolically label cDC1s with azido groups in situ. In Aim 2, targeted delivery of tumor neoantigens and adjuvants or liposomal vaccines to azido-labeled cDC1s in lymph nodes via click chemistry will be explored, with a goal of improving neoantigen-specific CTL responses and the overall antitumor efficacy against poorly-immunogenic solid tumors. In Aim 3, targeted conjugation and surface display of immunomodulatory agents on cDC1s in lymph nodes will be explored to regulate cDC1-T cell interactions and amplify CTL responses. We hypothesize that cytokines, once conjugated, can be retained on cDC1 surface for hours to provide continuous stimulation to effector T cells during the T cell priming process. The completion of this project will lead to new immunotherapies with robust antitumor efficacy against solid tumors and reduced off-target side effects. Further, the cDC1 recruitment, labeling and targeting technology will also be promising for future development of therapies against autoimmune disorders and infectious diseases.