Cytosolic Delivery of Tumor Antigens into Dendritic Cells

项目摘要/摘要 癌症疫苗最近已经成为一种选择性地激活T细胞对抗癌症的方法。治疗方法 是以多肽为基础的，称为肿瘤抗原，来自肿瘤中具有免疫原性的多肽序列。 另一类肿瘤抗原称为新抗原，是由尚未检测到的肿瘤突变引起的。 通过免疫系统。这些带有肿瘤抗原或新抗原的癌症疫苗可以促进抗原特异性， 而不是通过产生新的或放大现有的免疫反应来激活T细胞 对抗肿瘤。尽管通过这些治疗观察到了有希望的抗癌免疫反应，但有效的 而且免疫系统的选择性激活仍然很困难。 有几个挑战限制了癌症疫苗进入临床：(1)充分利用 抗原提呈细胞的抗原很难实现，这极大地影响了多肽是否被 被加工或呈递给T细胞。(2)多肽的蛋白酶体加工很难预测，这可能 导致形成除所需抗原以外的既不与人类白细胞抗原等位基因结合，也不与人类白细胞抗原等位基因结合的肽片段 激活免疫反应。抗原递送系统可以在改进癌症疫苗方面发挥关键作用。这个 递送系统可以执行两个关键功能，这两个功能的缺失目前限制了癌症的疗效 疫苗：促进针对树突状细胞(DC)并促进胞浆递送。 这项建议描述了一种炭疽递送系统的开发，用于递送肿瘤抗原。我的 最重要的假设是，炭疽机制非常适合输送肿瘤抗原，因为它 可以有效地进行蛋白质转位。在自然界中，递送系统将毒素输送到细胞胞浆中 会迅速导致细胞死亡。主要部件很容易改装，以便将非本地货物运输到 细胞，包括治疗性多肽、蛋白质，甚至小分子。这项建议将发展 炭疽病毒递送系统具有两个新功能：靶向树突状细胞和递送肿瘤抗原。这些 将开发增强体内肿瘤抗原活性的特征(目标1)并阐明抗原 处理和列报(目标2)。这项工作的影响将不仅仅是开发一个有效的工具 用来运送肿瘤抗原。这也为T细胞特异性肿瘤抗原的鉴定和研究奠定了基础 激活，这最终将导致开发出更好的肿瘤抗原，用于癌症疫苗 诊所和其他地方。 培训计划和环境允许设计和研究炭疽输送系统与 潘特鲁特实验室(麻省理工学院)、欧文实验室(麻省理工学院科赫癌症综合研究所)和吴实验室(达纳- 法伯癌症研究所)。拟议的研究将利用现有的设备和资源进行 在这些实验室中，以及科赫研究所斯旺森生物技术中心的设施。

PROJECT SUMMARY/ABSTRACT Cancer vaccines have recently emerged as a selective way to activate T cells against cancer. The treatments are based on peptides, called tumor antigens, derived from peptide sequences in tumors that are immunogenic. Another class of tumor antigens, called neoantigens, arise from mutations in tumors that have not been detected by the immune system. These cancer vaccines with tumor antigens or neoantigens can promote antigen-specific, rather than nonspecific, T-cell activation, by either generating new or amplifying existing immune responses against tumors. Despite the promising anti-cancer immune responses observed with these treatments, effective and selective activation of the immune system remains difficult. Several challenges have limited the translation of cancer vaccines into the clinic: (1) Sufficient uptake of the antigens by antigen presenting cells is difficult to achieve, which greatly influences whether the peptides are processed or presented to T cells. (2) Proteasomal processing of the peptides is difficult to predict, which can result in the formation of peptide fragments, other than the desired antigen, that neither bind to an HLA allele nor activate an immune response. Antigen delivery systems can play crucial roles in improving cancer vaccines. The delivery systems can perform two critical functions, which the absence of currently limits the efficacy of cancer vaccines: promote targeting to dendritic cells (DCs) and facilitate cytosolic delivery. This proposal describes the development of an anthrax delivery system for delivering tumor antigens. My overarching hypothesis is that the anthrax machinery is well suited for delivering tumor antigens, because it can efficiently perform protein translocation. In nature, the delivery system transports toxins into the cell cytosol that rapidly induce cell death. The main components are easily modified for transporting non-native cargo into cells, including therapeutic peptides, proteins, and even small molecules. This proposal will develop the anthrax delivery system with two new features: to target dendritic cells and to deliver tumor antigens. These features will be developed to enhance tumor antigen activity in vivo (Aim 1) and to shed light on antigen processing and presentation (Aim 2). The impact of this work will extend beyond developing an effective tool for tumor antigen delivery. It will also facilitate the identification and study of tumor antigens selective for T cell activation, which will ultimately lead to the development of better tumor antigens for cancer vaccines in the clinic and beyond. The training plan and environment permits the design and study of the anthrax delivery system with the Pentelute lab (MIT), Irvine lab (Koch Institute for Integrative Cancer Research at MIT), and Wu lab (Dana- Farber Cancer Institute). The proposed studies will be performed with the equipment and resources available in these labs, and with the facilities available at the Swanson Biotechnology Center at the Koch Institute.