Host and fungal factors important for the cryptococcal intracellular niche

对隐球菌细胞内生态位很重要的宿主和真菌因素

• 批准号: 10717537
• 负责人: Felipe H Santiago-Tirado
• 金额: $ 39.13万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-15 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10717537
• 关键词: Acquired Immunodeficiency Syndrome; Affect; Area; Basic Science; Behavior; Biochemical; Biological; Biology; Buffers; Cause of Death; Cells; Cellular biology; Cessation of life; Characteristics; Clinical Research; Cryptococcus; Cryptococcus neoformans; Data; Development; Disease; Disease Progression; Early Endosome; Foundations; Fungal Genes; Generations; Genetic; Genetic Techniques; Geographic Locations; Glucuronic Acids; Goals; Hyaluronic Acid; Hybrids; Image; Immune; Immune Evasion; Immune signaling; Immune system; Immunocompromised Host; Immunologic Techniques; Immunologics; Incidence; Infection; Inflammatory; Inhalation; Intervention; Investigation; Knowledge; Link; Lysosomes; Macrophage; Mammalian Genetics; Mediating; Medical; Membrane; Microscopy; Mission; Modeling; Molecular; Mycoses; National Heart, Lung, and Blood Institute; National Institute of Allergy and Infectious Disease; Outcome; Pathogenesis; Patients; Permeability; Phagosomes; Phenotype; Phosphatidylinositols; Population; Prevention; Process; Property; Public Health; Reporting; Research; Resolution; Role; Signal Transduction; Surface; Techniques; Testing; Therapeutic Intervention; United States National Institutes of Health; Work; Yeasts; capsule; effective therapy; fungal genetics; fungus; immunological status; mortality; mutant; pathogen; pathogenic fungus; pathogenic microbe; permissiveness; prevent; rab GTP-Binding Proteins; therapeutically effective

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.

项目总结/摘要 了解细胞内病原体如何在其宿主细胞中生存，有助于更好地管理/预防 他们的疾病，以及基础生物学的发现。在这个应用程序中，我们的目标是开始 阐明了最常见的真菌病原体之一隐球菌所使用的策略和机制 在巨噬细胞内生存。隐球菌病的治疗是低于标准的，导致莫尔- 根据地理区域的不同，从20%到近90%不等。这种真菌能够 在宿主细胞内存活是疾病进展的主要驱动力之一，临床研究表明， 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， 控制内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内和分子机制背后， 细胞存活，这是该领域知识的一个重大空白。为了实现这一目标， 应用是定义和表征巨噬细胞中含有隐球菌的吞噬体（CCP），以及 了解宿主和真菌因素在产生这种细胞内生态位中的作用。我们假设 隐球菌主动靶向Rab GTP酶和磷酸肌醇，以延迟其phag的正常成熟。 哦。这使得真菌因子，如荚膜透明质酸和葡萄糖醛酸，调节酸化 的CCP，导致真菌允许的生态位。促炎信号，部分由Rab 20效应介导 在吞噬体成熟时，对抗这种真菌操纵并防止生态位建立。我们计划测试 这一假说通过（1）定义和表征C.幼稚和活化的新生儿 巨噬细胞;（2）确定和探讨真菌因子在生态位建立中的作用。如果完成，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）， tus）的特性，使隐球菌生活在细胞内，使我们能够查明潜在的领域， 干预以阻断细胞内复制。这些目标的实现将在实地产生积极影响， 生成隐球菌用于在巨噬细胞中生存的策略的详细分子描述， 宿主细胞的反应此外，由于缺乏良好表征的细胞内生存策略， 真菌，这里创造的知识将影响其他病原真菌的理解和研究。