Epigenetic subversion in Leishmania macrophage infection (ELATION)

表观遗传控制失调已被认为是人类疾病的主要来源，范围从癌症到微生物感染。许多病毒、细菌和真核病原体感染哺乳动物细胞，并共同进化出调节宿主细胞表达谱的策略，以促进自身的生存。尽管对人类健康造成了毁灭性的后果，但这种宿主细胞颠覆背后的表观遗传机制却知之甚少。在这里，我们应用原生动物寄生虫利什曼原虫作为一个独特的模型系统，通过研究允许这些寄生虫逃避巨噬细胞免疫代谢功能并利用这些基本免疫细胞进行细胞内生存的表观遗传机制，来解除这一主要的科学障碍。初步研究揭示了一系列针对巨噬细胞表观遗传酶“赖氨酸特异性去甲基酶1”（LSD1）的抑制剂，这些抑制剂以宿主为导向的方式杀死细胞内利什曼原虫。我们认为利什曼原虫破坏巨噬细胞LSD1功能，为细胞内寄生虫的生存建立有利条件，研究我们系统中LSD1功能将为细胞内感染的表观遗传机制和病理巨噬细胞极化状态的发展提供新的见解。我们将开发创新的化学生物学工具，这将有助于理解宿主细胞LSD1在巨噬细胞感染中的作用。具体来说，生物素化的LSD1抑制剂将成为ChemSeq的有力工具，LSD1的化学降解物（PROTACs）将允许化学驱动的功能丧失研究，dcas9介导的前药释放将允许亚细胞控制表观遗传抑制剂的作用。因此，申请人的综合和协同专业知识将为利什曼原虫的表观遗传巨噬细胞颠覆提供深入的机制洞察，此外还将作为研究其他细胞内感染的蓝图。

Dysregulation of epigenetic control has been recognized as a major source of human disease, ranging from cancer to microbial infection. Many viral, bacterial and eukaryotic pathogens infect mammalian cells and have co-evolved strategies to modulate the expression profile of their host cells promoting their own survival. Despite the devastating consequences for human health, the epigenetic mechanisms underlying such host cell subversion are only poorly understood. Here we apply the protozoan parasite Leishmania as a unique model system to lift this major scientific barrier by investigating the epigenetic mechanisms that allow these parasites to evade macrophage immuno-metabolic functions and to exploit these essential immune cells for intracellular survival. Preliminary work revealed a series of inhibitors targeting the macrophage epigenetic enzyme ‘lysine specific demethylase 1’ (LSD1) that lead to killing of intracellular Leishmania in a host-directed fashion. We propose that Leishmania subverts macrophage LSD1 functions to establish permissive conditions for intracellular parasite survival and that investigating LSD1 functions in our system will provide new insight into epigenetic mechanisms underlying intracellular infection and the development of pathological macrophage polarization states. We will develop innovative chemical biology tools that will strongly contribute to the understanding of the role of host cell LSD1 in macrophage infection. Specifically, biotinylated LSD1 inhibitors will be powerful tools for ChemSeq, chemical degraders (PROTACs) of LSD1 will allow chemically driven loss-of-function studies and dCas9-mediated prodrug release will allow subcellular control of epigenetic inhibitor action. Thus, the combined and synergistic expertise of the applicants will deliver deep mechanistic insight into epigenetic macrophage subversion by Leishmania which in addition will serve as a blueprint to study other intracellular infections.