Harnessing the therapeutic potential of histotripsy focused ultrasound-induced immunogenic cancer cell death

项目摘要/摘要 免疫疗法对引起免疫系统认可的癌症非常有效。 系统(如黑色素瘤)，但对免疫检测基本上看不见的癌症仍然无效 (例如，胰腺癌)。癌症免疫治疗的进展将需要干预措施，使癌症 对免疫系统来说更明显。越来越多的证据表明聚焦超声(FUS) 肿瘤消融术可能就是这种干预措施。通过非侵入性地破坏癌细胞，热和机械 FUS的模式已被证明能触发针对肿瘤的令人惊讶的强大免疫反应。我们有 发现组织摩擦学，一种机械融合的非热模式，刺激了一种强大的系统性抗肿瘤 免疫反应强到足以引起远处、非消融肿瘤部位的异常消退--效果不是 通常见于传统疗法，如放射或热消融。组织旅游是一项技术， 目前正被引入临床使用；因此，了解其机制将是当务之急 组织摩擦免疫刺激的基础。我们的初步研究指出了一系列逐步发生的事件 或许可以解释这一现象。首先，组织摩擦学导致亚细胞癌细胞抗原在 以保持其免疫原性完整性的方式。第二，组织摩擦学诱导癌细胞经历一种 细胞自杀的特定途径称为坏死性下垂--一种吸引炎症和免疫的死亡途径 注意，有效地启动免疫系统识别癌症抗原。接下来的是一个进步的 CD8T细胞向远处肿瘤的渗透伴随着另一种称为癌细胞死亡的途径 铁下垂-一种死亡途径，最近被发现是免疫治疗启动的关键机制 CD8T细胞杀死癌细胞。 在这项提案中，我们将回顾这些步骤，以了解组织试验如何发挥其异常有效的作用 免疫效果。首先，我们将对引起组织摩擦组织空化的参数进行定量微调 最大限度地释放免疫原性肿瘤抗原。接下来，我们将重点关注坏死性下垂的早期诱导 确定这是否是一种必要的局部先兆事件，在这种情况下组织摩擦病的后来表现 免疫刺激依赖于。然后，我们将研究CD8T细胞驱动的铁下垂的后期过程 确定这是否是组织摩擦学的远距离、非局部性影响的中介机制。最后，我们 将利用从这些研究中获得的机械性见解来开发和测试潜在的临床前 组织摩擦学对肿瘤抗原释放、坏死性下垂和铁性下垂的影响的策略 最大限度地用于癌症免疫治疗。我们已经组建了一支在FUS方面拥有专业知识的多学科团队， 免疫学和癌症免疫疗法继续这项工作，这有望揭示洞察力和战略 将癌症免疫治疗的影响带给更广泛的需要治愈的患者。

PROJECT SUMMARY/ABSTRACT Immunotherapy can be highly effective against cancers that elicit some recognition from the immune system (e.g., melanoma), but it remains ineffectual against cancers that are largely invisible to immune detection (e.g., pancreatic cancer). Advances in cancer immunotherapy will require interventions that can make cancers more apparent to the immune system. A growing body of evidence suggests that focused ultrasound (FUS) tumor ablation could be that intervention. By non-invasively disrupting cancer cells, thermal and mechanical modes of FUS have been shown to trigger surprisingly potent immune responses against tumors. We have found that histotripsy, a non-thermal mode of mechanical FUS, stimulates a powerful and systemic anti-tumor immune response strong enough to cause abscopal regression of distant, non-ablated tumor sites – effects not generally seen with traditional therapies like radiation or thermal ablation. Histotripsy is a technology that is presently being introduced into clinical use; therefore, it will be imperative to understand the mechanistic underpinnings of histotripsy immunostimulation. Our preliminary studies point to a stepwise series of events that may explain this phenomenon. First, histotripsy causes the release of subcellular cancer cell antigens in a manner that preserves their immunogenic integrity. Second, histotripsy induces cancer cells to undergo a specific pathway of cellular suicide called necroptosis – a death pathway that attracts inflammation and immune attention, effectively priming the immune system to recognize cancer antigens. What follows is a progressive infiltration of CD8+ T cells into distant tumors that is accompanied by another pathway of cancer cell death called ferroptosis – a death pathway recently discovered to be the critical mechanism by which immunotherapy-primed CD8+ T cells kill cancer cells. In this proposal, we will retrace these steps to understand how histotripsy exerts its unusually potent immune effects. First, we will quantitatively fine-tune the parameters of histotripsy tissue cavitation that cause maximally immunogenic tumor antigen release. Next, we will focus on the early induction of necroptosis to determine if this is a necessary local precursor event on which later manifestations of histotripsy immunostimulation depend. Then, we will examine the later process of CD8+ T cell-driven ferroptosis to determine if this is the mechanism by which the distant, abscopal effects of histotripsy are mediated. Finally, we will leverage mechanistic insights gained from these investigations to develop and test potential preclinical strategies with which the effects of histotripsy on tumor antigen release, necroptosis, and ferroptosis could be maximized for cancer immunotherapy. We have assembled a multidisciplinary team with expertise in FUS, immunology and cancer immunotherapy to pursue this work, which promises to reveal insights and strategies to bring the impact of cancer immunotherapy to a wider range of patients in need of cure.