Project 4: Interrogating and harnessing age-related IFN signaling and innate immunity in HCC prevention and therapy

项目摘要--项目4 原发性肝癌，主要是肝细胞癌，是目前最致命的恶性肿瘤之一。 衰老是肝细胞癌发生的高危因素，尽管其潜在的机制尚不清楚。 老化的肝脏的特征是免疫抑制微环境的逐渐发展， 由慢性干扰素信号、代谢变化以及先天免疫和获得性免疫改变所致。 因此，肝脏肿瘤对免疫治疗的反应很差。项目4的目标是阐明干扰素的作用。 等炎性细胞因子参与衰老相关肝脏免疫格局的改变。这个项目 是由我们在最近的实验中意外发现的。在剖析其分子机制时 利用可诱导的基因打靶系统Mx1-cre，我们确定了一种强大的肿瘤抑制作用 多聚肌苷-多胞苷(PolyIC)，一种诱导干扰素表达的合成dsRNA的作用。这些数据显示在 干扰素信号不仅挑战了IL1a-IL6细胞因子通路在肝脏肿瘤发生中的广为人知的理论，而且 也为肝癌的免疫治疗开辟了新的策略。不过，初步数据也显示，注射 PolyIC进入老年小鼠引发了截然不同的免疫反应，实际上加剧了肝癌的进展 如果在肿瘤晚期给药。因此，我们假设干扰素和其他相关的炎性细胞因子具有 在肝细胞癌发展中的双向或矛盾作用，取决于年龄和肿瘤分期。为了测试这一点 假设，我们将广泛询问干扰素信号在单细胞NASH-肝癌模型中的作用 决议。我们还将进一步开发和优化数学模型和TI(肿瘤生成指数)计算 定量测量致瘤信号强度、肿瘤分期和预后的系统，并评估 各种手法或治疗策略对肿瘤的抑制作用。值得注意的是，初步数据还显示 PolyIC在肝脏中强劲地诱导PD-L1的表达，这促使我们测试PolyIC的组合 和PD-L1/PD-1阻断治疗青年和老年小鼠肝癌。我们将广泛调查 先天免疫和获得性免疫功能的协同激活如何有效地抑制原发和 肝脏的转移性肿瘤进展。最后，我们将利用新建立的小鼠肿瘤 模型，系统地寻找肝脏特异性免疫抵抗的因素和机制。全 在这个雄心勃勃的项目中，拟议的实验的一部分只能与Shadel，Adams和 Kaech拥有互补的专业知识和核心。

PROJECT SUMMARY – PROJECT 4 Primary liver cancer, mainly hepatocellular carcinoma (HCC), is now one of the most deadly malignant diseases. Aging is a high-risk factor for HCC development, although the underlying mechanisms are poorly understood. The aging liver is characterized by progressive development of an immunosuppressive microenvironment, contributed by chronic interferon (IFN) signaling, metabolic changes and altered innate and adaptive immunity. Thus, liver tumors are poorly responsive to immunotherapy. The goal of project 4 is to elucidate the roles of IFN and other inflammatory cytokines in aging-related changes of the hepatic immunological landscape. This project was prompted by our unexpected finding in most recent experiments. In dissecting molecular mechanisms of liver tumorigenesis with an inducible gene targeting system, Mx1-cre, we identified a robust tumor-inhibitory effect of polyinosinic-polycytidylic acid (polyIC), a synthetic dsRNA that induces IFN expression. These data on IFN signaling not only challenge a widely known theory of IL1a-IL6 cytokine circuit in liver tumorigenesis, but also open up new strategies for HCC immunotherapy. However, preliminary data also showed that injecting polyIC into aged mice triggered sharply different immune responses and actually aggravated HCC progression if given at late tumor stages. Thus, we hypothesize that IFN and other related inflammatory cytokines have bidirectional or paradoxical roles in HCC development, depending on ages and tumor stages. To test this hypothesis, we will extensively interrogate the roles of IFN signaling in a NASH-HCC model at single cell resolution. We will also further develop and optimize a math model and a TI (tumorigenic index) calculation system to quantitatively measure tumorigenic signal strength, tumor stages and prognosis, and also evaluate tumor-inhibitory effects of various manipulation or treatment strategies. Of note, preliminary data also showed robust induction of PD-L1 expression by polyIC in the liver, which prompted us to test a combination of polyIC and PD-L1/PD-1 blockade in treatment of liver cancer in young and old mice. We shall extensively investigate how coordinated activation of innate and adaptive immune functions can effectively suppress primary and metastatic tumor progression in the liver. Finally, we shall take advantage of newly established mouse tumor models, to systematically search for liver-specific factors and mechanisms of resistance to immunotherapy. All of the proposed experiments in this ambitious project can only be done in collaboration with Shadel, Adams and Kaech with complementary expertise and the Cores.