Molecular & cellular basis for host-pathogen interactions

分子

• 批准号: 7110976
• 负责人: Gregory A Bohach
• 金额: $ 205.61万
• 依托单位: UNIVERSITY OF IDAHO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-15 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7110976
• 关键词: Molecular; cellular; basis; host; pathogen

EXCEED THE SPACE PROVIDED. 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 (At) 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 evolutionary conserved fromfungi 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.

超越空间 假如。 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致命的疾病 免疫功能低下人群的数量不断增加。伊曲康唑和两性霉素 B 是唯一 目前可用于治疗侵入性菌丝生长逃避宿主先天的情况的治疗方法 免疫系统。然而，它们的体内有效性较低，并且 IA 患者的预后较差。 寻找（At）毒力因子一直存在问题，因为明显候选物中的突变确实 不降低毒力。有趣的是，大多数影响发病机制的基因都会减慢菌丝形成的速度。 延长，也许可以给主机更多的时间进行防御。 Af 生长为延伸的菌丝体 通过极化菌丝生长通过培养基。这种增长方式需要新材料的不断涌现 移动到菌丝生长的尖端。我们的实验室一直致力于阐明DopA的功能， 从真菌到哺乳动物进化上保守的蛋白质家族的创始成员。早期工作 我们实验室的结果表明 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的菌丝生长的能力是关键 免疫功能低下患者避免先天免疫的机制，是一个主要贡献因素 丝状真菌病原体毒力的影响因素。将研究影响真菌生长的突变 动物细胞系。 dopA 突变体的毒力将在小鼠侵袭性肺中进行评估 曲霉病模型。具体目标 2 将检验 Af DopA (DopeyA) 和 An DopA 蛋白的假设 代表极化细胞生长所需的细胞蛋白运输的新颖且重要的组成部分 对环境信号的反应。 DopA 蛋白将通过 GFP 融合定位在活细胞中。这 将研究 DopA 在其他已知极性决定因素的定位中的作用。多巴胺相互作用 将通过多种方法鉴定蛋白质，以阐明极性生长的机制。这 该方法将有助于理解将信号传导与菌丝联系起来的分子机制 生长。具体目标 3 将检验 Af 具有神秘性周期的假设，该周期可以被操纵 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人员来说是无价的 研究烟曲霉。