Host and fungal factors important for the cryptococcal intracellular niche

项目摘要/摘要 了解细胞内病原体如何在宿主细胞中生存已导致更好的管理/预 他们疾病的发明，以及基础生物学的发现。在此应用程序中，我们的目标是从 阐明一种最常见的真菌病原体之一--隐球菌所使用的策略和机制 新生杆菌，在巨噬细胞内生存。隐球菌病的治疗低于标准，导致更多的 人才比例从20%到近90%不等，具体取决于地理区域。这种真菌有能力 在宿主细胞内生存是疾病进展的主要驱动力之一，临床研究表明，宿主细胞内的 巨噬细胞中的细胞存活与患者的死亡率相关。然而，分子机制是 治理内部化和细胞内生存的能力尚不清楚，阻碍了更多 有效的治疗方法。我们的长期目标是了解细胞和分子机制背后的内部 细胞存活，这是该领域知识的一个重大差距。朝着这个目标前进，这个的目标 应用是定义和表征巨噬细胞中含有隐球菌的吞噬小体(CCP)，以及 了解宿主和真菌因素在细胞内生态位生成中的作用。我们假设 隐球菌能主动靶向Rab GTP酶和磷脂酰肌醇，以延缓其PHAG的正常成熟。 来吧。这允许真菌因素，如透明质酸和葡萄糖醛酸，来调节酸化。 产生了真菌允许的生态位。促炎信号，部分由Rab20效应介导 在吞噬体成熟时，对抗这种真菌操纵，防止生态位的建立。我们计划测试 这一假说是通过(1)定义和表征新生隐球菌在幼稚和激活状态下的细胞内生态位 确定和探索真菌因子在生态位建立中的作用。如果完工，我们将 已经确定了遗传(真菌基因)、表型(CCP特性)和免疫学(宿主的免疫状态) TU)使隐球菌能够在细胞内生存的特征，使我们能够精确定位 阻断细胞内复制的干预。实现这些目标将在#年对实地产生积极影响。 生成隐球菌用来在巨噬细胞和 宿主细胞如何做出反应。此外，考虑到缺乏具有良好特征的细胞内生存策略， 真菌，这里创造的知识也将影响对其他病原真菌的理解和研究。

PROJECT SUMMARY / ABSTRACT Understanding how intracellular pathogens survive in their host cells has led to better management/pre- vention of their diseases, as well as discovery of fundamental biology. In this application, we aim to start elucidating the strategies and mechanisms used by one of the commonest fungal pathogens, Cryptococcus neoformans, to survive inside macrophages. The treatment of cryptococcal disease is subpar, resulting in mor- talities that range from 20% to almost 90%, depending on the geographical region. The ability of this fungus to survive inside host cells is one of the main drivers of disease progression, and clinical studies show that intra- cellular survival in macrophages correlates with patient’s mortality. However, the molecular mechanisms that govern internalization and the ability to survive intracellularly are not known, hampering the development of more effective therapeutics. Our long-term goal is to understand the cellular and molecular mechanisms behind intra- cellular survival, a significant gap in knowledge in the field. Moving towards that goal, the objectives of this application are to define and characterize the cryptococcal-containing phagosome (CCP) in macrophages, and understand the role of host and fungal factors in the generation of this intracellular niche. We hypothesize that Cryptococcus actively targets Rab GTPases and phosphoinositides to delay the normal maturation of its phag- osome. This allows fungal factors, such as capsular hyaluronic acid and glucuronic acid, to modulate acidification of the CCP, resulting in a fungal permissive niche. Pro-inflammatory signals, mediated in part by Rab20 effects on phagosomal maturation, counter this fungal manipulation and prevent niche establishment. We plan to test this hypothesis by (1) defining and characterizing the intracellular niche of C. neoformans in naïve and activated macrophages; and (2) identify and explore the role of fungal factors in niche establishment. If completed, we will have identified the genetic (fungal genes), phenotypic (CCP properties) and immunological (host’s immune sta- tus) characteristics that enable Cryptococcus to live intracellularly, allowing us to pinpoint potential areas of intervention to block intracellular replication. Completion of these aims will have a positive impact in the field by generating a detailed molecular description of the strategies Cryptococcus uses to survive in macrophages and how host cells respond. Moreover, given the scarcity of well characterized intracellular survival strategies in fungi, the knowledge created here will impact the understanding and studies of other pathogenic fungi as well.