Hematopoietic stem cells overcome treatment resistance to adoptive cellular therapy against malignant gliomas

项目摘要和摘要 高级别胶质瘤，包括成人复发的胶质母细胞瘤和儿童的脑干胶质瘤 总是致命的。利用免疫疗法驾驭免疫系统已经取得了重大进展， 然而，在鼠类和人类系统中针对实体瘤的治疗，在恶性胶质瘤的背景下， 大多数宿主仍然死于疾病。免疫治疗中产生治疗耐药性的两个主要因素 对抗恶性胶质瘤的是1)肿瘤的异质性，以及2)肿瘤内的免疫抑制 微环境和宿主的造血系统。我们的团队最近证明了伴随而来的 移植造血干细胞(HSC)结合免疫治疗可克服治疗失败 直接应对这两个挑战的过继细胞疗法和检查点抑制(Flores等人)。 自然通讯。在新闻发布会上)。解决肿瘤异质性的一种新颖而创新的方法是利用 造血干细胞联合移植和过继细胞治疗。移植的HSCs在几小时内迁移到颅内肿瘤 分化为树突状细胞，可原位捕获肿瘤抗原并呈现给过继转移和 宿主肿瘤浸润性淋巴细胞，明显维持T细胞在其他部位的激活 免疫抑制肿瘤微环境。此外，我们最近发布的数据表明，一部小说 肝干细胞移植联合免疫治疗关闭多种关键免疫调节机制 肿瘤微环境内的通路同时包括PD-L-1、转化生长因子β、诱导型一氧化氮合酶和诱导型一氧化氮合酶。肝星状细胞 此外，恶性胶质瘤内内源性宿主MDSCs和TAMs也被取代，从而减少了整体调控细胞。 我们怀疑HSC转移影响内源性抑制细胞的增殖或募集 为了肿瘤。这种抑制途径的减少可能是维持T细胞的一个主要因素 激活。这项提案将集中于肝星状细胞取代内源性免疫调节的机制。 并增加肿瘤内过继转移的肿瘤反应性T细胞的激活 微环境。当HSCs关闭免疫抑制调节通路时，它们同时增加了肿瘤- 反应性T细胞活化。如果成功，我们机构正在进行的和不久的将来的临床研究可以增加 儿童恶性胶质瘤过继细胞治疗的疗效。我们的假设是，造血干细胞 通过持续的T淋巴细胞交叉激发克服过继细胞疗法的治疗耐药性 关闭肿瘤微环境内的调节通路。该项目的目标是：目标 1.确定HSC来源的树突状细胞是否具有呈递逃逸肿瘤的抗原的能力 过继细胞治疗；目的2.评估造血干细胞同时靶向多个 肿瘤微环境中的调控途径；目的3.了解HSC+的耐药机制 非根治疗法受试者的过继细胞疗法。

PROJECT SUMMARY AND ABSTRACT High grade gliomas including recurrent glioblastoma in adults and brain stem gliomas in children are invariably fatal. Harnessing the immune system using immunotherapy has made significant strides towards treatment against solid tumors in both murine and human systems, however, in the setting of malignant gliomas, the majority of hosts still succumb to disease. Two major contributors to treatment resistance in immunotherapy against malignant gliomas are 1) tumor heterogeneity, and 2) immunosuppression within both the tumor microenvironment and the hosts' hematopoietic system. Our group has recently demonstrated that concomitant transfer of hematopoietic stem cells (HSC) with immunotherapy leads to overcoming of treatment failure to both adoptive cellular therapy and checkpoint inhibition by directly addressing these two challenges (Flores et al. Nature Communications. In press). A novel and innovative way to address tumor heterogeneity is by leveraging HSC co-transfer with adoptive cellular therapy. Transferred HSCs migrate to intracranial tumor within hours and differentiate into dendritic cells that capture tumor antigens in situ and present to both adoptively transferred and host tumor infiltrating lymphocytes, demonstrably perpetuating T cell activation within the otherwise immunosuppressive tumor microenvironment. In addition, our recently published data demonstrates a novel approach of concomitant transfer of HSCs with immunotherapy shuts down multiple key immunoregulatory pathways within the tumor microenvironment simultaneously including PD-L-1, TGFβ, iNOS, and IDO-1. HSCs also supplant endogenous host MDSCs and TAMs within malignant glioma decreasing overall regulatory cells. We suspect that the HSC transfer impacts either the proliferation or recruitment of endogenous suppressive cells to tumor. This reduction in suppressive pathways is likely a major contributor to the maintenance of T cell activation. This proposal will focus on the mechanisms by which HSCs supplant endogenous immunoregulatory cells within the tumor and increase activation of adoptively transferred tumor-reactive T cells within the tumor microenvironment. As HSCs turn off immunosuppressive regulatory pathways, they concurrently increase tumor- reactive T cell activation. If successful, ongoing and near future clinical studies at our institution can increase efficacy of adoptive cellular therapy in children with malignant gliomas. Our HYPOTHESIS is that HSCs overcome treatment resistance to adoptive cellular therapy by continual cross-priming of T lymphocytes while shutting down regulatory pathways both within the tumor microenvironment. The AIMS of this project are to:AIM 1. Determine if HSC-derived dendritic cells have the capacity to present antigens from escaped tumor after adoptive cellular therapy; AIM 2. Evaluate the mechanisms by which HSCs simultaneously target multiple modulatory pathways within the tumor microenvironment; AIM 3. Understand resistance mechanisms to HSC + adoptive cellular therapy in subjects with non-curative treatment.