Protective Role of Nonclassical Monocytes in Immunotherapies for Solid Cancers

非经典单核细胞(在人类中被确认为CD14dimCD16+)显示出一种独特的巡视或调查能力 血管内皮细胞在稳态和炎症期间的管腔侧。非古典 单核细胞在循环中发挥作用，帮助清除血管系统中的病原体和碎片。我们最近 发现非经典单核细胞在血管系统发挥作用，通过协调来防止肿瘤转移 对转移的肿瘤细胞的杀伤和清除。非经典成分的抗肿瘤免疫潜能 巡逻单核细胞与越来越多的促肿瘤和促转移功能的证据相反 许多肿瘤类型中的髓系细胞。在目前的方案中，我们假设非经典单核细胞 抗肿瘤功能支持实体瘤患者CAR T细胞的扩增和疗效 肿瘤。因此，我们建议的一个主要目标是确定单核细胞疗法是否使用抗肿瘤药物 非经典单核细胞与现有的CAR T免疫治疗相结合将提高疗效。我们会 使用质量细胞术研究癌症患者的单核细胞亚群，以确定新的有助于 很容易确定拟议的免疫疗法对患者可能有多成功。目标1将确定独特的 多重复发肉瘤患者与健康人非经典单核细胞标志物的比较 质量细胞术。目标1将使用现有GD2 CAR T试验的库存样本在 美国国立卫生研究院临床中心。目标2将检验以下假设：非经典单核细胞在 与实体瘤转移的免疫治疗联合使用时，可促进抗肿瘤免疫。 AIM 2将同时使用异种移植人源化小鼠和同基因小鼠肿瘤模型。目标3将研究 CAR T细胞免疫联合非经典单核细胞治疗的安全性和初步疗效 多发性复发、转移性或进展性儿童实体瘤的细胞治疗。在目标3中，我们 将启动第二代GD2 CAR T细胞试验，用于多次复发的骨肉瘤患者和 神经母细胞瘤。考虑到巡逻单核细胞的潜在抗肿瘤效果，我们计划在 单用非经典单核细胞和联合CAR T细胞治疗的阶段临床试验 是这场审判的一部分。这个项目有3名调查人员：一名校外调查人员，一名NCI校内调查人员，一名在 美国国立卫生研究院临床中心。从这项提案的结果中，我们将获得对以下角色的重要洞察力 不同髓系细胞亚群对CAR T细胞抗肿瘤反应的促进和抑制作用 实体肿瘤的治疗方法。作为一个研究团队，我们正处于独特的地位，直接解决 人类患者单核细胞和其他髓系细胞与CAR T细胞的相互作用。我们的调查结果是 研究小组将显著推进将导致有效的CAR T细胞治疗的知识 肿瘤。由于单核细胞与受检查点抑制物调节的T细胞发生类似的相互作用 试验，我们预计我们的发现将深入了解单核细胞：T细胞相互作用在 检查点抑制疗法。

Nonclassical monocytes (identified as CD14dimCD16+ in humans) exhibit a unique ability to `patrol' or survey the luminal side of the vascular endothelium both at steady state and during inflammation. Nonclassical monocytes function in circulation to aid in removing pathogens and debris from the vasculature. We recently found that nonclassical monocytes function in the vasculature to prevent tumor metastasis by orchestrating the killing and clearance of metastasizing tumor cells. The anti-tumor immune potential of nonclassical patrolling monocytes is in contrast to the growing evidence for pro-tumorigenic and pro-metastatic functions of myeloid cells in many tumor types. In the current proposal, we hypothesize that nonclassical monocytes function in an anti-tumoral manner to support CAR T cell expansion and efficacy in patients with solid tumors. Thus, one major goal of our proposal is to determine whether monocyte therapy using anti-tumoral nonclassical monocytes in combination with existing CAR T immunotherapy would improve efficacy. We will use mass cytometry to study monocyte subsets in cancer patients to identify new markers that will help readily determine how successful a proposed immunotherapy may be for patients. Aim 1 will identify unique markers of nonclassical monocytes in multiply relapsed sarcoma patients versus healthy subjects using mass cytometry. Aim 1 will be performed using banked samples from the existing GD2 CAR T trial at the NIH Clinical Center. Aim 2 will test the hypothesis that nonclassical monocytes play a functional role in promoting anti-tumor immunity when used in combination with immunotherapy for solid tumor metastasis. Aim 2 will use both xenografted humanized mouse and syngeneic mouse tumor models. Aim 3 will study the safety and preliminary efficacy of CAR T cell immunotherapy in combination with nonclassical monocyte cell therapy for patients with multiple relapsed, metastatic or progressive pediatric solid tumors. In Aim 3, we will initiate a second generation GD2 CAR T cell trial for multiply relapsed patients with osteosarcoma and neuroblastoma. Given the potential anti-tumor efficacy of patrolling monocytes we plan to initiate an early phase clinical trial delivering nonclassical monocytes alone and in combination with CAR T cell therapy as part of this trial. There are 3 investigators in this project: one extramural, one intramural at NCI, and one at the NIH Clinical Center. From the results of this proposal, we will achieve significant insight into the roles of various myeloid cell subpopulations on promoting and inhibiting the anti-tumoral responses of CAR T cell therapies for solid tumors. We are uniquely poised as a research team to directly address the role of monocytes and other myeloid cells in interacting with CAR T cells in human patients. The findings of our research team will significantly advance the knowledge that will lead to effective CAR T cell therapy for solid tumors. As similar interactions of monocytes occur with T cells that are modulated by checkpoint inhibitor trials, we anticipate that our findings will shed insight into monocyte:T cell interactions in the context of checkpoint inhibition therapy.