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（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IC的最重要类型。腹腔内念珠菌病（IAC）和其他非血流IC的研究较少。委员会包括两个实体：腹膜炎（腹膜感染）和脓肿（念珠菌和脓液聚集，与健康组织隔离）。最近的论文和我们中心的数据表明，IAC至少和念珠菌血症一样常见，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）腔通过粘膜转移到血管系统或直接从血管导管引入。另一方面，IAC是将念珠菌引入正常无菌的腹膜腔作为腹膜炎的并发症。 透析或更常见的是胃肠道渗漏或穿孔的结果。在后一种情况下，念珠菌与粪便混合，在大多数情况下，胃肠道细菌如大肠杆菌。杆菌白色念珠菌仍然是IAC最常见的原因，而非念珠菌。现在白色念珠菌属在念珠菌血症中占优势。对C.白色念珠菌引起IAC的原因知之甚少。我们采用了一种简单的和可重复的小鼠模型的C。白色念珠菌IAC，其复制了从全身性腹膜炎到局限性腹腔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145 C的表达。白念珠菌基因在腹膜炎。此外，我们证明了小鼠模型在区分突变C的相对毒力方面是敏感的。白念珠菌菌株，表明它是非常适合的发病机制的研究。这些数据提供了有价值的见解，生物过程中激活的C。albicans的体外培养结果表明，C. IAC期间白念珠菌基因表达与DC或OPC显著不同。最近，我们进行了RNA-Seq（cDNA深度测序）来全面定义C。从腹膜炎患者回收的腹膜液中的白色念珠菌基因表达。在这个项目中，我们将测试两个假设：1）C。白色念珠菌阐述阶段特异性 腹腔和腹膜内的基因表达谱;和2）C.白念珠菌基因在IAC中的时空调控在发病机制中起着独特的作用。在我们的第一个具体目标中，我们将使用RNA-Seq来测量C。白念珠菌基因表达在小鼠和人类IAC期间。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暗示特定的C。白念珠菌基因在IAC发病机制中的作用。除了提供有助于IAC的基因和生物学过程的见解外，该项目还将导致未来对发病机制的特定研究。这项研究将产生关于发病机制的新假设，并有助于为该领域的研究人员提供基因和途径的选择。此外，这些数据还可以为开发新的治疗、诊断和疫苗策略确定优先目标。