Immunometabolism in Cancer and Inflammation

该实验室一直在采取一种方法，涉及更多的考虑内的相互作用，并适应，代谢生态位。我们假设免疫细胞的代谢适应导致其环境的改变。因此，浸润有免疫细胞的肿瘤将具有不同的代谢燃料可用性，这将在生长期间驱动肿瘤的适应，反之亦然。我们最近发现，腹膜腔是一个独特的代谢生态位。使用详细的生化分析，代谢组学，特异性抑制剂，通量分析和高清晰度显微镜与NCI-Frederick光学显微镜分析实验室的组合，我们发现，腹膜驻留巨噬细胞（pRes）利用效应器功能的小生境。这种共生的生化相互作用在腹膜小生境导致我们检查可能的代谢适应癌症的腹膜。简而言之，我们在癌症中发现了两个这种关系的例子。首先，我们发现腹膜间隙的癌症会导致常驻的腹膜巨噬细胞表达免疫反应基因-1（Irg 1），积累衣康酸，并以Irg 1依赖性方式促进肿瘤生长。因此，我们发现来自晚期癌症患者腹水的骨髓细胞表达Irg 1。在第二个实施例中，我们发现来自荷癌小鼠的嗜中性粒细胞适应其代谢，以利用葡萄糖耗尽的肿瘤微环境。这种适应允许它们抑制T细胞功能，即使控制中性粒细胞不能。这里再次有迹象表明这种机制在人类身上。乳腺癌患者外周血中具有这些代谢特征的中性粒细胞数量较多。除了对癌症的直接研究外，我们还确定了一氧化氮（NO）在巨噬细胞活化过程中发生的代谢重编程中的作用。虽然这一机制在很大程度上被忽视，我们发现，这些细胞的代谢特征的几个完全是由于NO的生产。NO对这些细胞的代谢适应的深远影响包括控制几个关键代谢物，包括衣康酸，柠檬酸，α-酮戊二酸，琥珀酸。重要的是，作为我们对代谢生态位的兴趣的一部分，我们发现巨噬细胞和腹腔灌洗液的体内特征与我们体外研究预测的一致。总之，我们的工作证明了先天免疫细胞的强大能力，不仅可以适应其代谢组合，而且可以通过改变代谢生态位的组成来潜在地发挥反式代谢效应。正在进行的工作更深入地探讨了NO和衣康酸在各种生理系统中的代谢作用。为了应对最近爆发的SARS-CoV-2，我们已经开始研究氯喹与Zn 2+组合的潜在治疗效果。众所周知，氯喹具有抗炎作用。最近，它已被证明，氯喹是一个有效的锌离子载体在体外。Zn 2+是RNA病毒（如SARS-CoV-2）使用的RNA依赖性RNA聚合酶（RdRp）的已知抑制剂。这提出了一种有趣的可能性，即氯喹可能通过两种机制对COVID-19疾病有益：抗炎和通过Zn 2+介导的RdRp抑制来抑制病毒复制。考虑到氯喹的毒性，我们假设局部鼻内应用与ZnCl 2联合可能会显著增加肺上皮细胞中的Zn 2+水平，同时限制全身毒性。我们正在测试这一假设，通过使用小鼠模型，Zn 2+检测器和质谱监测肺白细胞和上皮细胞中的Zn 2+水平和氯喹的药代动力学。

The laboratory has been taking an approach that involves more consideration of the interactions within, and adaptations to, metabolic niches. We hypothesize that metabolic adaptation of immune cells results in modification of their environment. As a consequence, tumors infiltrated with immune cells will have different availability of metabolic fuels that will drive adaptation of tumors during growth and vice versa. We recently found that the peritoneal cavity is a unique metabolic niche. Using a combination of detailed biochemical analysis, metabolomics, specific inhibitors, flux analysis, and high definition microscopy with the NCI-Frederick Optical Microscopy Analysis Laboratory we found that peritoneal resident macrophages (pRes) exploit that niche for effector function. This symbiotic biochemical interaction in the peritoneal niche led us to examine possible metabolic adaptation to cancer in the peritoneum. In brief, we found two examples of that relationship in cancer. In the first, we found cancer in the peritoneal space causes resident peritoneal macrophages to express Immunoresponsive Gene-1 (Irg1), accumulate itaconic acid, and promote tumor growth in an Irg1-dependent manner. Accordingly, we found that myeloid cells from the ascites of advanced cancer patients expressed Irg1. In the second example, we found that neutrophils from cancer bearing mice adapt their metabolism in order to exploit the glucose depleted tumor microenvironment. This adaptation permits them to suppress T cell function even when control neutrophils cannot. Here again there were indications of this mechanism in humans. Peripheral blood of breast cancer patients had greater numbers of neutrophils with these metabolic characteristics. In addition to direct studies of cancer, we have defined the role of nitric oxide (NO) in the metabolic reprogramming that occurs during macrophage activation. Although this mechanism has been largely overlooked, we found that several of the metabolic characteristics of these cells are solely due to the production of NO. The profound effects of NO on the metabolic adaptations of these cells includes control of several key metabolites including itaconate, citrate, alpha-ketoglutarate, and succinate. Importantly, as part of our interest in the metabolic niche, we find that in vivo signatures of macrophages and in peritoneal lavage fluid match those predicted by our in vitro studies. Taken together our work demonstrates the powerful ability of innate immune cells to not only adapt their metabolic portfolios but to potentially exert metabolic effects in trans by altering the composition of the metabolic niche. Ongoing work more deeply explores the metabolic effects of NO and itaconate in a variety of physiological systems. In response to the recent outbreak of SARS-CoV-2 we have begun to investigate the potential therapeutic efficacy of Chloroquine in combination with Zn2+. Chloroquine is known to have anti-inflammatory effects. Recently, it has been shown that Chloroquine is an effective Zn2+ ionophore in vitro. Zn2+ is a known inhibitor of the RNA-dependent RNA polymerase (RdRp) used by RNA viruses such as SARS-CoV-2. This raises the intriguing possibility that Chloroquine may be beneficial in COVID-19 disease through two mechanisms; anti-inflammatory and suppression of viral replication via Zn2+-mediated suppression of RdRp. Given the reported toxicity of Chloroquine we hypothesized that local, intranasal application in combination with ZnCl2 might substantially increase Zn2+ levels in lung epithelial cells while limiting systemic toxicity. We are testing this hypothesis by using mouse models, Zn2+ detectors and mass spectroscopy to monitor Zn2+ levels in lung leukocytes and epithelial cells and Chloroquine pharmacokinetics.