Biomaterials for Targeted Modulation of Conventional Type 1 Dendritic Cells

总结 免疫疗法已经显示出治愈癌症的巨大希望，特别是检查点封锁的成功 和嵌合抗原受体（CAR）T细胞疗法，但其实用性仍然受到低患者应答率的限制， 对许多实体瘤的疗效差和/或严重的副作用。这些问题推动了 一种新的免疫疗法，可以引起有效和持久的细胞毒性T淋巴细胞（CTL）反应，并减少 脱靶毒性靶向调节1型常规树突状细胞（cDC 1），一种上级DC亚群 在抗原交叉呈递中，在淋巴结中将能够最佳地激活CTL应答，并导致稳健的免疫应答。 免疫疗法，但迄今尚未实现。该项目的主要目标是开发一个宏观尺度的 将免疫细胞归巢大孔材料与代谢聚糖整合的基于材料的系统 标记以实现cDC 1的体内募集、标记和靶向。有了这个材料系统，我们的目标是开发 一种用于免疫调节剂，包括抗原， 佐剂和细胞因子，在淋巴结中的cDC 1，并进一步开发有效和安全的癌症免疫疗法。 为了实现这一点，一种可注射的大孔生物材料，载有cDC 1募集趋化因子和叠氮基- 糖将用于募集和代谢标记具有化学标签的cDC 1（例如，叠氮基）。这些 化学标记的cDC 1可以从生物材料迁移到淋巴结，用于随后的靶向缀合 免疫调节剂通过高效和生物正交点击化学。将组织实验 围绕三个目标。在目标1中，制备了具有独立可调的孔径、刚度 粘度和趋化因子释放动力学，以及每个参数对免疫系统的影响。 为了合理设计大孔材料， 优先募集并原位代谢标记具有叠氮基的cDC 1。在目标2中，靶向递送肿瘤 通过点击化学将新抗原和佐剂或脂质体疫苗与淋巴结中的叠氮基标记的cDC 1结合， 目的是提高新抗原特异性CTL应答和整体抗肿瘤疗效 针对免疫原性差的实体瘤。在目标3中，靶向缀合和表面展示 将探索免疫调节剂对淋巴结中cDC 1的作用，以调节cDC 1-T细胞相互作用， 扩增CTL应答。我们假设，细胞因子，一旦结合，可以保留在cDC 1表面， 小时，以在T细胞引发过程中向效应T细胞提供连续刺激。完成 该项目将导致新的免疫疗法对实体瘤具有强大的抗肿瘤功效， 脱靶副作用此外，cDC 1募集、标记和靶向技术也将有望用于 针对自身免疫性疾病和感染性疾病的疗法的未来发展。

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.