MNT OF HYPHAL POLARITY BY DOPA PROTEIN AND ITS ROLE IN ASPERGILLUS PATHOGENESIS

多巴蛋白对菌丝极性的影响及其在曲霉菌发病中的作用

• 批准号: 7959730
• 负责人: BRUCE L MILLER
• 金额: $ 20.59万
• 依托单位: UNIVERSITY OF IDAHO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7959730
• 关键词: Affect; Amphotericin B; Animals; Aspergillosis; Aspergillus; Aspergillus fumigatus; Cell Line; Cells; Computer Retrieval of Information on Scientific Projects Database; Disease; Dopa; Effectiveness; Essential Genes; Funding; Genes; Genetic; Grant; Growth; Hyphae; Immune system; Immunocompromised Host; Individual; Institution; Itraconazole; Laboratories; Life; Link; Lung; Mammals; Meiosis; Methods; Modeling; Molecular; Mus; Mutation; Mycelium; Natural Immunity; Pathogenesis; Population; Protein Family; Proteins; Research; Research Personnel; Resources; Role; Signal Transduction; Source; Testing; Time; United States National Institutes of Health; Virulence; Virulence Factors; Work; base; cell growth; fungus; in vivo; member; mutant; novel; outcome forecast; pathogen; polarized cell; protein transport; response; tool

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Aspergillus fumigatus (Af) is the major cause of invasive aspergillosis (IA), an often-fatal disease in the growing population of immunocompromised individuals. Itraconazole and amphotericin B are the only currently available treatments for those cases where invasive hyphal growth escapes the host's innate immune system. However, their effectiveness in vivo is low and the prognosis for individuals with IA is poor. The search for (Af) virulence factors has been problematic because mutations in the obvious candidates do not reduce virulence. Interestingly, the majority of genes that affect pathogenesis slow the rate of hyphal extension, perhaps giving the host more time to mount a defense. Af grows as a mycelium that extends through medium via polarized hyphal growth. This mode of growth requires that new materials be constantly moved to the growing tip of the hypha. Our laboratory has been involved in elucidating the function of DopA, the founding member of a protein family that is evolutionarily conserved from fungi to mammals. Earlier work from our lab indicates that DopA is an essential gene that is involved in protein trafficking. Specific Aim 1 will test the hypothesis that the ability to establish and maintain highly polarized hyphal growth is a key mechanism for avoidance of innate immunity in immunocompromised patients, and is a major contributing factor in virulence of filamentous fungal pathogens. Mutations that affect fungal growth will be studied in animal cell lines. The virulence of dopA mutants will be assessed in the mouse invasive pulmonary aspergillosis model. Specific Aim 2 will test the hypothesis that Af DopA (DopeyA) and An DopA proteins represent a novel and essential component of cellular protein trafficking required for polarized cell growth in response to environmental signaling. DopA protein will be localized in living cells by using GFP fusions. The role of DopA in the localization of other known polarity determinants will be investigated. DopA interacting proteins will be identified by a number of methods to elucidate the mechanisms of polar growth. This approach will contribute to an understanding of the molecular mechanisms that link signaling to hyphal growth. Specific Aim 3 will test the hypothesis that Af has a cryptic sexual cycle that can be manipulated to develop meiotic genetics as a tool for Af. The addition of sexual genetics will be invaluable to investigators studying Aspergillus fumigatus.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目和 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 烟曲霉 (Af) 是侵袭性曲霉病 (IA) 的主要原因，而侵袭性曲霉病是一种在不断增长的免疫功能低下人群中常常致命的疾病。对于侵入性菌丝生长逃避宿主先天免疫系统的病例，伊曲康唑和两性霉素 B 是目前唯一可用的治疗方法。 然而，它们的体内有效性较低，并且 IA 患者的预后较差。寻找（Af）毒力因子一直存在问题，因为明显候选物中的突变不会降低毒力。 有趣的是，大多数影响发病机制的基因都会减慢菌丝延伸的速度，这可能会给宿主更多的时间来进行防御。 Af 作为菌丝体生长，通过极化菌丝生长延伸到培养基中。 这种生长方式需要新物质不断移动到菌丝的生长尖端。 我们的实验室一直致力于阐明 DopA 的功能，DopA 是从真菌到哺乳动物进化上保守的蛋白质家族的创始成员。 我们实验室的早期工作表明 DopA 是参与蛋白质运输的重要基因。具体目标 1 将检验以下假设：建立和维持高度极化菌丝生长的能力是免疫功能低下患者避免先天免疫的关键机制，并且是丝状真菌病原体毒力的主要影响因素。将在动物细胞系中研究影响真菌生长的突变。 dopA 突变体的毒力将在小鼠侵袭性肺曲霉病模型中进行评估。具体目标 2 将检验以下假设：Af DopA (DopeyA) 和 An DopA 蛋白代表了响应环境信号而极化细胞生长所需的细胞蛋白运输的一种新颖且重要的成分。 DopA 蛋白将通过 GFP 融合定位在活细胞中。将研究 DopA 在其他已知极性决定因素的定位中的作用。 DopA 相互作用蛋白将通过多种方法进行鉴定，以阐明极性生长的机制。这种方法将有助于理解将信号传导与菌丝生长联系起来的分子机制。 具体目标 3 将检验以下假设：Af 具有神秘的性周期，可以通过操纵该性周期来开发减数分裂遗传学作为 Af 的工具。性遗传学的加入对于研究烟曲霉的研究人员来说是无价的。