The Translational Response of C. neoformans to Oxidative Stress and Macrophage Phagocytosis.

环境真菌新型隐球菌能够适应人类宿主，并且在易感个体中，可以引起致命的脑膜炎，如果没有抗真菌治疗是致命的。C.在全世界范围内，约15%的艾滋病相关死亡是由新生儿引起的，并且是移植人群中死亡率和同种异体移植物丢失的重要原因。与巨噬细胞的相互作用对感染的结果很重要。C.新生儿表达促进存活的因子，包括防止吞噬溶酶体酸化的尿素酶，以及使活性氧类解毒和修复氧化损伤的活性氧应激反应因子。我们目前令人信服的初步数据表明，尿素酶和活性氧反应效应器的调节在mRNA翻译水平通过激酶Gcn 2。Gcn 2是C.新变型，其磷酸化真核生物翻译起始因子2（eIF 2），从而调节翻译起始。在这次合作中，Panepinto实验室在C.新形式的协同创新的计算和基因组学方法开发的麦克马纳斯实验室研究翻译反应的氧化应激和执行的第一个研究的翻译调控在C。巨噬细胞感染期间的新生儿。该提案包括两个目标。第一个目标将使用核糖体分析和RNA-seq来研究响应于氧化应激的全基因组翻译调控，并确定GCN 2缺失对ROS响应基因表达和对巨噬细胞氧化杀伤的易感性的后果。第二个目的是研究C.在骨髓源性巨噬细胞的细胞内生长过程中的新生儿，及其对Gcn 2的依赖性。这些研究将提供一个全面的看法，如何C。在氧化应激反应中以及在巨噬细胞感染过程中，新生儿对其翻译组进行重编程。由于翻译控制的根本重要性，在巨噬细胞适应期间选择用于翻译的过程预计包括用于未来治疗开发的潜在靶点。

The environmental fungus Cryptococcus neoformans is capable of adapting to the human host, and in susceptible individuals, can cause deadly meningitis that is fatal without antifungal therapy. C. neoformans is responsible for ~15% of AIDS-related deaths worldwide, and is a significant cause of mortality and allograft loss in the transplant population. Interactions with macrophages are important to the outcome of infection. In response to the macrophage intracellular environment, C. neoformans expresses factors that promote survival, including the enzyme urease that prevents acidification of the phago-lysosome, and reactive oxygen stress response factors that detoxify reactive oxygen species and repair oxidative damage. We present compelling preliminary data to suggest that both urease and ROS response effectors are regulated at the level of mRNA translation through the kinase Gcn2. Gcn2 is the sole kinase in C. neoformans that phosphorylates eukaryotic translation initiation factor 2 (eIF2), thereby regulating translation initiation. In this collaboration, the expertise of the Panepinto lab in translational regulation in C. neoformans synergizes with the innovative computational and genomics approaches developed by the McManus lab to investigate the translational response to oxidative stress and perform the first study of translational regulation in C. neoformans during macrophage infection. The proposal consists of two aims. The first aim will use ribosome profiling and RNA-seq to investigate the genome wide translational regulation in response to oxidative stress and determine the consequences of GCN2 deletion on ROS response gene expression and susceptibility to oxidative killing by macrophages. The second Aim will examine the translational regulation employed by C. neoformans during intracellular growth in bone marrow derived macrophages, and its dependence on Gcn2. These studies will provide a comprehensive view of how C. neoformans reprograms its translatome in response to oxidative stress, and during macrophage infection. Due to the fundamental importance of translational control, the processes selected for translation during macrophage adaptation are expected to include potential targets for future therapeutic development.