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: 8829141
• 负责人: M. Hong Thi NGUYEN
• 金额: $ 19.57万
• 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 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8829141
• 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; Health; 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; response; transcriptome sequencing

DESCRIPTION (provided by applicant): 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 developmentof novel therapeutic, diagnostic and vaccine strategies.

描述（由申请人提供）：侵袭性念珠菌病 (IC) 是美国医院最常见的真菌感染，死亡率高达 40%。血流感染（念珠菌血症）通常被认为是最重要的 IC 类型。腹内念珠菌病 (IAC) 和其他非血流念珠菌病的研究较少。 IAC 包括两个实体：腹膜炎（腹膜感染）和脓肿（与健康组织隔离的念珠菌和脓液的集合）。最近论文和我们中心的数据表明，IAC 至少与念珠菌血症一样常见，并且死亡率相似。然而，这些疾病在重要方面有所不同。念珠菌血症最常见的进入途径是从胃肠道 (GI) 腔通过粘膜易位到脉管系统或从血管导管直接引入。另一方面，IAC 是在将念珠菌引入通常无菌的腹膜腔之后，作为腹膜感染的并发症。 透析或更常见的是胃肠道渗漏或穿孔。在后一种情况下，念珠菌与粪便物质混合，并且在大多数情况下，还与胃肠道细菌（例如大肠杆菌）混合。白色念珠菌仍然是 IAC 的最常见原因，而非念珠菌。白色念珠菌现在在念珠菌血症中占主导地位。白色念珠菌引起 IAC 的细胞和分子机制尚不清楚。我们采用了一种简单且可重复的白色念珠菌 IAC 小鼠模型，该模型复制了从全身性腹膜炎到局部腹内脓肿的感染的病理生理学和进展。我们使用 nanoString nCounter 测定来测量腹膜炎期间 145 个白色念珠菌基因的表达。此外，我们证明小鼠模型在区分突变型白色念珠菌菌株的相对毒力方面很敏感，这表明它非常适合发病机制的研究。这些数据为了解白色念珠菌在体内激活的生物过程提供了宝贵的见解，并揭示了 IAC 期间白色念珠菌的基因表达与 DC 或 OPC 有很大不同。最近，我们进行了 RNA-Seq（cDNA 深度测序），以全面确定腹膜炎患者腹腔液中白色念珠菌的基因表达。在这个项目中，我们将测试两个假设：1）白色念珠菌详细阐述了特定阶段 腹膜腔和脓肿内的基因表达谱； 2) IAC 期间受时空调节的白色念珠菌基因对发病机制做出了独特的贡献。在我们的第一个具体目标中，我们将使用 RNA-Seq 来测量小鼠和人类 IAC 期间白色念珠菌的基因表达。在我们的第二个具体目标中，我们将使用我们的小鼠模型来研究 IAC 发病机制中特定的白色念珠菌基因。除了提供对导致 IAC 的基因和生物过程的见解外，该项目还将引导未来对具体发病机制的研究。这项研究将产生关于发病机制的新假设，并有助于为该领域研究人员可以追求的基因和途径的选择提供信息。此外，这些数据还可以确定开发新型治疗、诊断和疫苗策略的优先目标。