Candida albicans gene expression during intra-abdominal infections

腹腔内感染期间白色念珠菌基因表达

• 批准号: 8642813
• 负责人: M. Hong Thi NGUYEN
• 金额: $ 25.39万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8642813
• 关键词: Abdominal Abscess; Abdominal Infection; Abscess; Accounting; Biological Assay; Blood Vessels; Candida; Candida albicans; Candidiasis; Catheters; Collection; Communicable Diseases; Complementary DNA; Complication; Data; Development; Diagnostic; Disease; Disseminated candidiasis; Escherichia coli; Extravasation; Feces; Functional disorder; Future; Gastrointestinal tract structure; Gene Deletion; Gene Expression; Gene Expression Profile; Genes; Goals; Greater sac of peritoneum; Hospitals; Human; Infection; Intra-abdominal; Lead; Literature; Measures; Modeling; Molecular; Molecular Profiling; Mucous Membrane; Mus; Mycoses; Operative Surgical Procedures; Pancreatitis; Paper; Pathogenesis; Pathway interactions; Patient Care; Patients; Perforation; Peritoneal; Peritoneal Dialysis; Peritoneal Fluid; Peritoneum; Peritonitis; Process; Publishing; Pus; RNA; Relative (related person); Research Personnel; Sampling; Sepsis; Site; Staging; Sterility; Surgeon; Testing; Tissues; Transcript; Vaccines; Virulence; candidemia; deep sequencing; gastrointestinal; gastrointestinal bacteria; gastrointestinal perforation; gene complementation; genome-wide; human disease; in vivo; insight; mortality; mouse model; mutant; nano-string; neutrophil; novel therapeutics; oropharyngeal thrush; pathogen; public health relevance; response; transcriptome sequencing

PROJECT SUMMARY Invasive candidiasis (IC), the most common fungal infection in U.S. hospitals, is associated with mortality rates as high as 40%. Bloodstream infections (candidemia) are generally accepted as the most important type of IC. Intra-abdominal candidiasis (IAC) and other non-bloodstream IC are less well-studied. IAC encompasses two entities: peritonitis (infection of the peritoneum) and abscesses (collections of Candida and pus that are walled-off from healthy tissue). Data from recent papers and our center indicate that IAC is at least as common as candidemia, and mortality rates are similar. Nevertheless, the diseases differ in important ways. The most common portals of entry for candidemia are translocation from the gastrointestinal (GI) lumen through the mucosa into the vasculature or direct introduction from vascular catheters. IAC, on the other hand, follows the introduction of Candida into the normally sterile peritoneal cavity as a complication of peritoneal dialysis or, more commonly, as a result of GI tract leakage or perforation. In the latter scenarios, Candida is admixed with fecal material and, in most cases, GI bacteria such as E. coli. Candida albicans remains the most common cause of IAC, whereas non-C. albicans species are now predominant in candidemia. The cellular and molecular mechanisms by which C. albicans causes IAC are poorly understood. We have adapted a simple and reproducible mouse model of C. albicans IAC that replicates the pathophysiology and progression of infection from generalized peritonitis to localized intra-abdominal abscesses. We used nanoString nCounter assays to measure expression of 145 C. albicans genes during peritonitis. Moreover, we demonstrated that the mouse model is sensitive at distinguishing the relative virulence of mutant C. albicans strains, indicating that it is well-suited to studies of pathogenesis. These data provided valuable insights into biologic processes that are activated by C. albicans in vivo, and revealed that C. albicans gene expression during IAC differs substantially from DC or OPC. More recently, we have performed RNA-Seq (deep sequencing of cDNA) to comprehensively define C. albicans gene expression within peritoneal fluid recovered from a patient with peritonitis. In this project, we will test two hypotheses: 1) C. albicans elaborates stage-specific gene expression profiles within the peritoneal cavity and abscesses; and 2) C. albicans genes that are temporal-spatially regulated during IAC make distinct contributions to pathogenesis. In our first specific aim, we will use RNA-Seq to measure C. albicans gene expression during IAC in mice and humans. In our second specific aim, we will use our mouse model to implicate specific C. albicans genes in the pathogenesis of IAC. In addition to providing insights into genes and biologic processes that contribute to IAC, the project will lead to future studies of specific mechanisms of pathogenesis. This study will generate new hypotheses about pathogenesis, and help inform choices of genes and pathways that can be pursued by investigators in the field. In addition, the data may identify priority targets for the development of novel therapeutic, diagnostic and vaccine strategies.

项目摘要 侵入性念珠菌病（IC）是美国医院中最常见的真菌感染，与死亡率有关 高达40％。血流感染（念珠菌血症）通常被认为是最重要的类型 我知道了。腹腔内念珠菌病（IAC）和其他非血流IC的研究较少。 IAC包含 两个实体：腹膜炎（腹膜感染）和脓肿（念珠菌和脓液的集合 从健康组织中脱下围墙）。最近的论文和我们的中心的数据表明，IAC至少一样常见 由于候选血症和死亡率相似。然而，这些疾病在重要方面有所不同。最多 候选血症的常见入口是胃肠道（GI）腔的转运 粘膜进入血管或血管导管的直接引入。另一方面，IAC遵循 将念珠菌引入正常无菌的腹膜腔中，作为腹膜透析的并发症或 更常见的是，由于胃肠道泄漏或穿孔。在后一种情况下，念珠菌与 粪便材料，在大多数情况下是胃肠道细菌，例如大肠杆菌。白色念珠菌仍然是最常见的 IAC的原因，而非c。白色疾病现在在候选血症中占主导地位。细胞和 白色念珠菌引起IAC的分子机制知之甚少。我们改编了一个简单的 和白色念珠菌IAC的可重现小鼠模型，复制了病理生理学和进展 从广义性腹膜炎到局部腹腔内脓肿的感染。我们使用了纳米弦ncounter 测量腹膜炎期间145个白色念珠菌基因表达的测定。而且，我们证明了 小鼠模型对区分突变体白色念珠菌菌株的相对毒力很敏感，表明它 非常适合发病机理研究。这些数据为生物过程提供了宝贵的见解 由白色念珠菌在体内激活，并揭示了白色念珠菌基因在IAC期间的表达有很大不同 来自DC或OPC。最近，我们进行了RNA-Seq（cDNA的深度测序）以全面 定义从腹膜炎患者中回收的腹膜液中白色念珠菌基因的表达。在这个 项目，我们将检验两个假设：1）白色念珠菌阐明了阶段特异性基因表达谱。 腹膜腔和脓肿； 2）在IAC期间暂时调节的白色念珠菌基因 对发病机理做出不同的贡献。在我们的第一个特定目标中，我们将使用RNA-Seq测量C。 小鼠和人类IAC期间白色疾病的基因表达。在我们的第二个特定目标中，我们将使用鼠标 模型将特定白色念珠菌基因暗示在IAC的发病机理中。除了提供洞察力 有助于IAC的基因和生物过程，该项目将导致对特定的未来研究 发病机理的机制。这项研究将产生有关发病机理的新假设，并有助于告知 该领域的研究人员可以追求基因和途径的选择。此外，数据可能 确定开发新型治疗，诊断和疫苗策略的优先目标。