The biology of Cryptococcus neoformans melanization

新型隐球菌黑化的生物学

基本信息

批准号：
10660435
负责人：
Arturo Casadevall
金额：
$ 84.15万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-01 至 2028-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10660435
关键词：
Acquired Immunodeficiency Syndrome Affect Anabolism Animals Antifungal Agents Basic Science Biochemical Biological Process Biology Cell Wall Cell model Cells Cellular biology Cessation of life Chemicals Chronic Complex Cryptococcus Cryptococcus neoformans Crystallization Cytoprotection Deposition Effector Cell Electromagnetic Energy Electrons Energy harvesting Equus caballus Family Fractionation Free Radicals Goals Host Defense Mechanism Human Immune Immunity Impairment Individual Infection Investigation Label Laccase Lead Libraries Light Lipids Location Macrophage Mammals Mediating Melanins Melanogenesis Melanosomes Metabolic Modeling Molecular Mus Mycoses NMR Spectroscopy Nature Organ Organism Paper Pathogenesis Pathogenicity Pathway interactions Pigments Plants Polyenes Polymers Polysaccharides Population Predisposition Process Property Radiation Reaction Research Resistance Role Science Structure Sunlight System Techniques Testing Therapeutic Uses Time Tissues Ultraviolet Rays Vesicle Virulence Work absorption acquired drug resistance crosslink cytotoxic drug development fungus glyphosate host-microbe interactions human pathogen immunosuppressed inhibitor insight interdisciplinary approach melanin inhibitor new therapeutic target novel pathogen pathogenic fungus polymerization prevent programs small molecule small molecule inhibitor solid state nuclear magnetic resonance targeted agent toxic metal vesicle transport

项目摘要

Cryptococcus neoformans (CN) is an important human fungal pathogen responsible for thousands of deaths each year, primarily in immunosuppressed individuals. CN makes melanin, a pigment that performs a variety of functions in the plant and animal kingdoms. In fungi, melanin reinforces cell walls, shields against ultraviolet radiation and toxic metals, harnesses high-energy electromagnetic radiation, and contributes to virulence. In addition to contributing to virulence, melanization reduces the susceptibility of fungal cells to antifungal agents and can contribute to the difficulty in treating fungal infections, which are often chronic and notoriously difficult to eradicate. Despite its importance, little is known about the structure of melanin because it is insoluble and amorphous, making it difficult to analyze. This research program takes a multidisciplinary approach to studying the problem of cryptococcal melanization, combining biochemical, cell biology, and spectroscopic (solid state NMR) techniques to uncover the mechanisms of melanization and its impact on the host-microbe interaction. The current application proposes to elucidate the vesicular pathway used to export melanin to the exterior of the cell, investigate the role of lipids in melanin synthesis, investigate how melanin affects the interactions between CN and macrophages, and identify small molecule inhibitors of melanogenesis. Agents that target melanin are potentially valuable because they could be applied against a broad array of pathogenic fungi. Four related but independent aims are proposed: Aim 1. To establish the mechanism for CN cell wall melanization; Aim 2. To determine how neutral lipids in lipid droplets influence melanin synthesis and deposition; Aim 3. To establish the mechanism for how melanization subverts the CN-macrophage interaction; and Aim 4. To identify CN melanin inhibitors and establish their mechanisms of action.

加密新外身（CN）是重要的人类真菌病原体，导致数千人死亡每年，主要用于免疫抑制的个体。 CN制作黑色素，一种表现多种的色素在动植物界的功能。在真菌中，黑色素增强了细胞壁，屏蔽紫外线辐射和有毒金属，利用高能电磁辐射，并有助于毒力。在除了有助于毒力，黑素化还降低了真菌细胞对抗真菌剂的敏感性并且可能有助于治疗真菌感染的困难，而真菌感染通常是长期且臭名昭著的消除。尽管它很重要，但对黑色素的结构知之甚少，因为它是不溶性和无定形，使得很难分析。该研究计划采用多学科的方法来学习隐球菌黑素化的问题，结合生化，细胞生物学和光谱状态（固态 NMR）技术可揭示黑素化机制及其对宿主微子相互作用的影响。当前的应用提议阐明用于将黑色素导出到外部的囊泡途径细胞，研究脂质在黑色素合成中的作用，研究黑色素如何影响 CN和巨噬细胞，并鉴定黑色素生成的小分子抑制剂。靶向黑色素的特工是潜在的有价值，因为它们可以用于广泛的致病真菌。四个相关，但是提出了独立目标：目标1。建立CN细胞壁黑色化的机制；目标2 确定脂质液滴中的中性脂质如何影响黑色素的合成和沉积；目标3。建立黑素化如何颠覆CN巨噬细胞相互作用的机制；目标4。确定CN 黑色素抑制剂并建立其作用机理。