Investigating TLR-agonist adjuvancy in STING-activating nanoparticle cancer vaccines

项目摘要/摘要 针对黑色素瘤的治疗性疫苗尚未实现其临床潜力。几项III期临床试验 评估针对癌症-睾丸抗原、全细胞裂解物或与癌症相关的疫苗的效果 抗原未能达到它们的治疗终点。这一失败是由于缺乏抗原特异性细胞毒性T细胞。 免疫后淋巴细胞增殖。众所周知，疫苗的效力需要时空排出两者。 淋巴结的抗原和佐剂，用于刺激先天免疫和抗原提呈。因为 由于其尺寸和物理化学性质，纳米颗粒疫苗能够精确地递送抗原和 对淋巴结中相关细胞类型的佐剂。然而，细胞内危险信号的足够放大 仍然具有挑战性。最近，我们实验室发现了一种两亲性嵌段共聚物，聚乙二醇-b-PC7A， 它直接结合并激活干扰素基因的刺激物(STING)。这种先天免疫受体 一般识别胞浆DNA，由环GMP-AMP合成酶(CGAS)加工为其天然配体2‘3’- 环状GMP-AMP(CGAMP)然而，在cGAS-cGAMP非依赖的情况下，PEG-b-PC7A直接与STING结合 过程，放大I型干扰素的分泌后，吞噬的抗原呈递细胞。我们有 图为用PC7A聚合物胶束和肿瘤相关抗原制剂接种荷瘤小鼠 会导致肿瘤生长受到抑制。虽然这种聚合物表现出显著的纳米粒子自组装，但pH- 反应性、内溶性性和刺激性，抗肿瘤免疫反应可能是难治的 在免疫抑制肿瘤模型中。因此，我将通过加入额外的免疫-来解决这个问题- 我们配方中的调节成分。尤其是炎性细胞因子的低表达 地址。我将用Toll样受体(TLR)激动剂制备PC7A纳米颗粒，以增加 以非冗余的方式释放细胞因子。而TLR和STING通路都集中在类型的表达上 I干扰素，适配器蛋白和信号通路(例如，NF-κB)的差异可以导致显著的 特殊激动剂接种后细胞因子表达动力学的变化。在此应用程序中，我将 筛选和鉴定包裹TLR激动剂的PC7A纳米粒以改善干扰素刺激 世代，和抗肿瘤免疫。我推测TLR-7激动剂咪喹莫特(R837)包裹了PC7A 由于TLR7/STING-IRF3/7诱导的非冗余，纳米粒子将显示出更好的抗肿瘤免疫能力 I型干扰素转录。这个应用程序将通过制定新的协同学类来展示创新 TLR-STING激动剂纳米颗粒，该提案适合于这一项目，因为显著的 PC7A聚合物纳米粒子的性质。

Project Summary/Abstract Therapeutic vaccination against melanoma has yet to realize its clinical potential. Several phase III clinical trials assessing efficacy of vaccination against cancer-testis antigens, whole cell lysates, or cancer associated antigens failed to meet their therapeutic endpoints. This failure is due to lack of antigen-specific cytotoxic T lymphocyte proliferation after vaccination. It is known vaccine efficacy requires spatiotemporal draining of both antigen and adjuvant to lymph nodes for stimulating innate immunity as well as antigen presentation. Because of their size and physicochemical properties, nanoparticle vaccines enable precision delivery of both antigen and adjuvant to relevant cell types in the lymph node. However, sufficient amplification of intracellular danger signals can remain challenging. Recently, our laboratory has discovered an amphiphilic block copolymer, PEG-b-PC7A, which directly binds and activates the stimulator of interferon genes (STING). This innate immune receptor generally recognizes cytosolic DNA, processed by cyclic GMP-AMP Synthase (cGAS) to its natural ligand 2’3’- cyclic GMP-AMP (cGAMP). However, PEG-b-PC7A directly binds to STING in a cGAS-cGAMP-independent process, amplifying the secretion of type I interferons after phagocytosis by antigen presenting cells. We have shown vaccinating tumor-bearing mice with a PC7A polymeric micelle and tumor-associated antigen formulation will lead to tumor growth inhibition. While this polymer shows remarkable nanoparticle self-assembly, pH- responsiveness, endosomolytic, and STING activating properties, anti-tumor immune response can be refractory in immunosuppressive tumor models. Therefore, I will address this problem by incorporating additional immuno- modulatory components in our formulation. Particularly, low expression of inflammatory cytokines will be addressed. I will formulate PC7A nanoparticle with toll-like receptor (TLR) agonists to increase expression of cytokines in non-redundant manners. While the TLR and STING pathways both converge on expression of type I interferons, the differences in adaptor proteins and signaling pathways (e.g. NF-κB) can lead to significant changes in the kinetics of cytokines expression after vaccination by unique agonists. In this application I will screen and identify PC7A nanoparticles encapsulating TLR agonists for improved interferon stimulation, CTL generation, and anti-tumor immunity. I hypothesize the TLR-7 agonist, Imiquimod (R837), encapsulated PC7A nanoparticles will show improved anti-tumor immunity due to non-redundancy in TLR7/STING-IRF3/7-induced transcription of type I interferons. This application will show innovation by formulating a new class of synergetic TLR-STING agonist nanoparticles, and the proposal is suited for this project because of the remarkable properties of the PC7A polymeric nanoparticles.