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

Toll样受体激动剂(TLRs)是一种很有前途的抗癌疫苗佐剂，因为它们能够 诱导产生强大免疫反应所必需的促炎细胞因子。然而，目前可用的 TLR激动剂受到一些限制，包括自我调节免疫抑制和不利的 局部药代动力学导致树突状细胞内的利用度较低。此外，目前基于TLR激动剂的 抗癌疫苗能产生强大的细胞毒性CD8T细胞反应，但不能产生CD4Th1辅助T细胞反应。 这对于诱导有效的、长期的抗肿瘤免疫至关重要。我们将应对这些重要挑战 通过药物发现和药物输送努力的协同结合。我们团队已经开发了一套 高度取代的咪唑喹啉类化合物，它们激活TLR7和/或8，并诱导显著更高的水平 细胞因子与FDA批准的TLR7激动剂咪喹莫特进行比较。我们的研究表明，促炎性疾病与 免疫抑制细胞因子可以通过结构修饰来调节。封装 这些新型激动剂在酸性pH响应性纳米颗粒(NPs)中导致了CD4和COB的强劲激活 T细胞和自然杀伤(NK)细胞，导致比游离激动剂更强的抗癌免疫反应 或被包裹在非pH响应性NPs中。重要的是，使用中空的皮内递送NP疫苗 微针平台导致Th1免疫反应增强，这是有效诱导 长期的抗肿瘤免疫。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 高效包裹在pH响应型纳米粒中，调整纳米粒的性质，以改善树突状细胞的靶向性 经中空微针给药后，研究NK细胞介导的抗体介导的增强作用 细胞毒性。修订后的R01赠款申请的具体目标包括： 目的1：设计和合成针对NP包埋优化的TLR7/8激动剂 目的2：优化pH响应型纳米粒处方，用于中空微针辅助ID传递 目的3：确定空心微针辅助ID给药后NP疫苗的抗癌效果 我们希望我们的研究将确定TLR激动剂的新设计原则和给药策略，以克服 克服现有抗癌疫苗的局限性，进一步推动肿瘤免疫治疗领域的发展。

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.