Epigenetic subversion in Leishmania macrophage infection (ELATION)

表观遗传控制的失调已被认为是人类疾病的主要来源，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，并共同进化策略来调节其宿主细胞的表达谱，促进其自身的存活。尽管对人类健康的破坏性后果，这种宿主细胞颠覆的表观遗传机制只是知之甚少。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，通过调查表观遗传机制，使这些寄生虫逃避巨噬细胞的免疫代谢功能，并利用这些必要的免疫细胞的细胞内生存，解除这一重大的科学障碍。初步工作揭示了一系列针对巨噬细胞表观遗传酶“赖氨酸特异性脱甲基酶1”（LSD 1）的抑制剂，这些抑制剂以宿主导向的方式杀死细胞内利什曼原虫。我们建议，利什曼原虫颠覆巨噬细胞LSD1功能，以建立允许的条件下，细胞内寄生虫的生存和调查LSD1功能在我们的系统将提供新的见解表观遗传机制的细胞内感染和病理性巨噬细胞极化状态的发展。我们将开发创新的化学生物学工具，这将大大有助于理解宿主细胞LSD 1在巨噬细胞感染中的作用。具体而言，生物素化的LSD1抑制剂将是ChemSeq的有力工具，LSD1的化学降解剂（PROTAC）将允许化学驱动的功能丧失研究，而dCas9介导的前药释放将允许表观遗传抑制剂作用的亚细胞控制。因此，申请人的组合和协同专业知识将提供对利什曼原虫的表观遗传巨噬细胞颠覆的深刻机制见解，此外，这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.