Lymph node-targeted codelivery of albumin-binding peptide antigens and di-adjuvant for melanoma combination immunotherapy

项目摘要 晚期黑色素瘤是一种高度侵袭性的癌症。而免疫治疗，如免疫检查点封锁 (ICB)已经使一些患者受益，大多数黑色素瘤患者对ICB没有反应。这很大程度上是由于缺乏 ICB的先前存在的靶细胞和检查点、肿瘤抗原的异质性和肿瘤免疫抑制。 ICB治疗效果可通过输送肿瘤抗原的疫苗配方来促进新的 ICB靶向抗肿瘤细胞，减轻肿瘤免疫抑制。化学定义的多肽疫苗是 因相对容易制造和良好的药物稳定性而颇具吸引力。多肽疫苗的成功 依赖于高效的交付。尽管对各种多肽疫苗配方进行了临床测试，但它们的治疗作用 由于递送和免疫调节问题，疗效一直受到限制，包括1)向 作用部位(淋巴结和抗原提呈细胞)，2)免疫刺激佐剂效果差，原因是 限制人类靶细胞亚群，3)限制佐剂/抗原共传递以增强抗原免疫原性， 4)克服肿瘤抗原异质性的能力有限；5)传递异质性的能力有限 抗原。我们的战略是开发一个高效的、时空靶向的多肽疫苗平台， 解决这些缺陷以改进ICB治疗：1)搭乘白蛋白顺风车运送多肽疫苗 针对淋巴结和抗原呈递细胞，2)二佐剂靶向广泛的细胞亚群 3)有效的二佐剂和佐剂/抗原共传递增强抗原的免疫原性，以及4)a 模块化系统提供异质多抗原，以克服肿瘤抗原的异质性。在我们的 初步研究，我们开发了白蛋白结合疫苗(AlbiVax)，将疫苗投放速度提高了100倍 小鼠，促进抗癌T细胞反应14倍，并提高黑色素瘤的治疗效果 临床基准。此外，通过使用纳米支架共同传递二佐剂和抗原，AlbiVax进一步 增强抗原免疫原性，提高黑色素瘤治疗效果。我们这项研究的目标是 将多抗原/双佐剂联合递送白蛋白(MADC-AlbiVax)作为联合递送的高效平台 一种双佐剂和多个异源多肽抗原对淋巴结和抗原提呈细胞的诱导 针对ICB黑色素瘤的一种有效、广泛和持久的联合免疫疗法。目标1是优化 MADC-AlbiVax型靶向多抗原/二佐剂共传递到淋巴结的模块化结构， 抗原提呈细胞和亚细胞位置，以实现最佳的抗肿瘤免疫调节；目标2是 用多种肿瘤抗原合成黑色素瘤MadC-AlbiVax并检测疫苗共传递和 免疫调节；目的3是评价黑色素瘤的治疗效果和安全性。 AlbiVax联合ICB在多种小鼠模型中的应用。这项工作的一个重要成果将是临床前 使用临床测试或使用的试剂共同交付化学定义疫苗的创新系统的验证 用于未来的临床评估。 1

Project Summary Advanced melanoma is a highly aggressive cancer. While immunotherapy such as immune checkpoint blockade (ICB) has benefited some patients, most melanoma patients do not respond to ICB. This is largely due to a lack of preexisting target cells and checkpoints for ICB, tumor antigenic heterogeneity, and tumor immunosuppression. ICB therapeutic efficacy can be promoted by vaccine formulations that deliver tumor antigens to induce new antitumor cells for ICB to target and reduce tumor immunosuppression. Chemically defined peptide vaccines are attractive for relatively easy manufacturing and good pharmaceutical stability. The success of peptide vaccines relies on efficient delivery. Despite clinical testing of various peptide vaccine formulations, their therapeutic efficacy has been limited due to delivery and immunomodulation issues including 1) poor vaccine delivery to the sites of action (lymph nodes and antigen-presenting cells), 2) poor immunostimulant adjuvant efficacy due to restricted target cell subsets in human, 3) limited adjuvant/antigen codelivery to enhance antigen immunogenicity, 4) limited ability to overcome tumor antigenic heterogeneity, and 5) limited ability to deliver heterogeneous antigens. Our strategy is to develop a high efficiency and spatiotemporally targeted peptide vaccine platform that addresses each of these deficiencies to improve ICB therapy: 1) albumin hitchhiking delivers peptide vaccines to lymph nodes and antigen-presenting cells, 2) a di-adjuvant targets a broad spectrum of cell subsets across species, 3) potent di-adjuvant and adjuvant/antigen codelivery enhance antigen immunogenicity, and 4) a modular system delivers heterogeneous multi-antigens to overcome tumor antigenic heterogeneity. In our preliminary studies, we developed albumin-binding vaccines (AlbiVax) to enhance vaccine delivery 100-fold in mice, promote anticancer T cell responses 14-fold, and improve melanoma therapeutic efficacy relative to a clinical benchmark. Moreover, by codelivering a di-adjuvant and antigens using a nanoscaffold, AlbiVax further potentiated antigen immunogenicity and promoted melanoma therapeutic efficacy. Our objective in this study is to engineer multi-antigen/di-adjuvant codelivery AlbiVax (mADC-AlbiVax) as an efficient platform that codelivers a di-adjuvant and multiple heterogenous peptide antigens to lymph nodes and antigen-presenting cells to elicit a potent, broad, and long-lasting immunity for ICB melanoma combination immunotherapy. Aim 1 is to optimize the modular structure of model mADC-AlbiVax for targeted multi-antigen/di-adjuvant codelivery to lymph nodes, antigen-presenting cells, and subcellular locations for optimal antitumor immunomodulation; Aim 2 is to synthesize melanoma mADC-AlbiVax using multiple tumor antigens and measure vaccine codelivery and immunomodulation; Aim 3 is to evaluate the melanoma therapeutic efficacy and safety of melanoma mADC- AlbiVax combined with ICB in multiple mouse models. A significant deliverable of this work will be preclinical validation of an innovative system to codeliver chemically-defined vaccines using clinically tested or used agents for future clinical evaluation. 1