TLR7/8 agonist design and delivery for effective anticancer immune response

Toll样受体（TLR）的激动剂是有希望的抗癌疫苗佐剂，因为它们能够 诱导产生强免疫应答所必需的促炎细胞因子。然而，目前 TLR激动剂具有许多局限性，包括自我调节免疫抑制和不利的免疫抑制。 局部药代动力学导致树突细胞内的可用性差。此外，目前基于TLR激动剂的 抗癌疫苗产生强烈的细胞毒性CD 8 T细胞应答但不产生CD 4 Th 1辅助T细胞应答， 这对于诱导有效的、长期的抗肿瘤免疫是关键的。我们将应对这些重大挑战 通过药物发现和药物递送努力的协同组合。我们的团队开发了一套 高度取代的咪唑并喹啉，其激活TLR 7和/或8并诱导显著更高水平的 与FDA批准的TLR 7激动剂咪喹莫特相比，我们的研究表明，促炎因子 免疫抑制细胞因子可以通过结构修饰来调节。封装 这些酸性pH响应性纳米颗粒（NPs）中的新型激动剂导致CD 4和COB的强烈活化， T细胞以及自然杀伤（NK）细胞，导致比游离激动剂更强的抗癌免疫应答 或包封在非pH响应性NP中的那些。重要的是，使用中空微球进行NP疫苗的皮内递送。 微针平台导致增强的Th 1免疫应答，这对于有效诱导 长期抗肿瘤免疫。我们将在这些令人兴奋的发现的基础上，进一步优化新的激动剂， 在pH响应性NP中的有效包封，调节NP性质以改善树突状细胞的靶向 在通过中空微针递送后，研究NK细胞介导的抗体介导的免疫增强。 细胞毒性此修订R 01补助金申请的具体目的包括： 目的1：设计和合成优化用于NP包封的TLR 7/8激动剂 目的2：优化用于中空微针辅助ID递送的pH响应性NP制剂 目的3：确定空心微针辅助ID递送后NP疫苗的抗癌功效 我们希望我们的研究将确定TLR激动剂的新设计原则和递送策略， 目前抗癌疫苗的局限性，并进一步推进癌症免疫治疗领域。

Agonists of toll like receptors (TLRs) are promising anticancer vaccine adjuvants because of their ability to induce proinflammatory cytokines necessary to generate a robust immune response. However, currently available TLR agonists suffer from a number of limitations including self-regulatory immunosuppression and unfavorable local pharmacokinetics resulting in poor availability within dendritic cells. Further, current TLR agonist-based anticancer vaccines generate a robust cytotoxic CD8 T cell response but not CD4 Th 1 helper T cell response, which is critical for inducing effective, long-term antitumor immunity. We will address these important challenges through a synergistic combination of drug discovery and drug delivery efforts. Our team has developed a suite of highly substituted imidazoquinolines, which activate TLR7 and/or 8 and induce significantly higher levels of cytokines compared to imiquimod, an FDA approved TLR7 agonist. Our studies show the balance between proinflammatory and immunosuppressive cytokines can be tuned through structural modifications. Encapsulation of these novel agonists in acidic pH responsive nanoparticles (NPs) resulted in robust activation of CD4 and COB T cells as well as natural killer (NK) cells, leading to a stronger anticancer immune response than free agonist or that encapsulated in non-pH responsive NPs. Importantly, intradermal delivery of NP vaccine using a hollow microneedle platform led to an enhanced Th1 immune response, which is essential for effective induction of long-term antitumor immunity. We will build on these exciting findings and further optimize the new agonists for efficient encapsulation in pH responsive NPs, tune the NP properties for improved targeting of dendritic cells following delivery via hollow microneedles, and investigate potentiation of NK cell-mediated antibody-mediated cellular cytotoxicity. The Specific Aims of this revised R01 grant application include: Aim 1: Design and synthesize TLR7/8 agonists that are optimized for NP encapsulation Aim 2: Optimize pH responsive NP formulation for hollow microneedle-assisted ID delivery Aim 3: Determine anticancer efficacy of NP vaccine following hollow microneedle-assisted ID delivery We expect our studies will identify new design principles and delivery strategies for TLR agonists that overcome the limitations of current anticancer vaccines and further advance the field of cancer immunotherapy.