Inhibition of C. albicans filamentation by a C. glabrata biofilm-produced factor

光滑念珠菌生物膜产生因子对白色念珠菌丝状化的抑制

• 批准号: 8910045
• 负责人: Sabrina Patrice Martinez-Anz
• 金额: $ 3.2万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8910045
• 关键词: 3-Dimensional; Acquired Immunodeficiency Syndrome; Adopted; Affect; Ammonium Sulfate; Antifungal Therapy; Area; Biochemical; Biological Assay; Cancer Patient; Candida; Candida albicans; Candida glabrata; Cells; Chromatography; Clinical; Complex; Data; Dental General Practice; Dentures; Development; Disease; Exclusion; Filament; Fungal Drug Resistance; Furuncles; Gene Targeting; Genitourinary system; Heating; High Pressure Liquid Chromatography; Hospitals; Human; Hydrophobic Interactions; Immunocompromised Host; Individual; Infection; Invaded; Ion Exchange; Laboratories; Lead; Lesion; Mass Spectrum Analysis; Microbial Biofilms; Modeling; Morphology; Mycoses; Oral; Oral candidiasis; Oral cavity; Oral health; Oral mucous membrane structure; Organism; Pathogenesis; Pathway interactions; Patients; Play; Population; Precipitation; Property; Proteins; Research; Research Personnel; Research Training; Role; Sepsis; Signal Transduction; Skin; Testing; United States; Virulence; Yeasts; attributable mortality; base; biophysical properties; design; effective therapy; gastrointestinal; improved; inhibitor/antagonist; insight; microbial community; novel; oral biofilm; oral cavity epithelium; oral fungal; oral lesion; oral tissue; pathogen; public health relevance; reconstitution; research study; response; therapeutic development; trait

 DESCRIPTION (provided by applicant): Candida species are the fourth leading cause of hospital-acquired bloodstream infections in the United States with an attributable mortality rate of 40-50%. Oral candidiasis is the most common fungal infection encountered in the general dental practice and immunocompromised individuals, including AIDS patients, are particularly susceptible. Candida albicans is the most frequently isolated species in oral thrush patients. C. albicans and C. glabrata are increasingly being co-isolated from fungal lesions in the oral cavity. C. albicans has the ability to undergo a morphological transition from single-celled yeast to hyphal filaments. This transition is required for virulence and plays an important role in the invasion of the oral mucosa as well as biofilm formation. Biofilms are complex microbial communities that are highly resistant to antifungal treatment and also important for the development and persistence of opportunistic yeast infections. Although C. glabrata does not readily form filaments, this species easily forms biofilms. While monospecies C. albicans biofilms have been well-studied, inter-Candida-species signaling interactions that affect filamentation, including filamentation in biofilms, are unknown. My preliminary data indicate that both C. albicans planktonic cells and biofilms are unable to form filaments in the presence of an established C. glabrata biofilm. Inhibition of C. albicans filamentation appears to occur in response to a secreted C. glabrata protein because complete inhibition is observed when C. albicans planktonic cells and biofilms are grown in the supernatant of an independently grown C. glabrata biofilm, the inhibitory activity is lost upon boiling the supernatant, and the inhibitoy factor can be precipitated from the supernatant by ammonium sulfate. Our laboratory has previously shown that constitutive high-level expression of UME6, a key filament-specific transcriptional regulator, is sufficient to generate a nearly complete filamentous population, driv increased biofilm formation and promote virulence. Interestingly, the factor produced by C. glabrata biofilms also completely inhibits C. albicans UME6-driven filamentation in both biofilms and planktonic cultures. Based on these results, my hypothesis is that the inhibitor of C. albicans filamentation produced by C. glabrata biofilms is a secreted factor that acts downstream of the UME6 pathway. In order to test this hypothesis, experiments in this proposal are designed to: 1) determine the identity of the C. glabrata biofilm-produced inhibitor of C. albicans filamentation, 2) determine the role that the C. glabrata biofilm-produced factor plays in inhibiting the virulence properties of a C. albicans UME6 expression strain as well as C. albicans clinical oral isolates. These studies are significant because the will provide important new insight into inter-Candida species signaling interactions that control filamentation of C. albicans, a major human oral fungal pathogen. Because of the important role that filamentation plays in C. albicans oral tissue invasion, biofilm formation, and pathogenesis, these studies are likely to provide information leading to the development of novel and more effective antifungal therapies to treat oral candidiasis.

 描述（由申请人提供）：念珠菌属是美国医院获得性血流感染的第四大原因，死亡率为 40-50%。口腔念珠菌病是一般牙科诊所和诊所中最常见的真菌感染。免疫功能低下的个体，包括艾滋病患者，特别容易在口腔热病患者中分离到白色念珠菌和光滑念珠菌。越来越多地与口腔中的真菌病变共同分离。 白色念珠菌能够经历从单细胞酵母到菌丝丝的形态转变，这种转变是毒力所必需的，并且在口腔粘膜的侵袭以及生物膜的形成中发挥着重要作用。对抗真菌治疗具有高度抵抗力，并且对于机会性酵母菌感染的发展和持续也很重要。尽管光滑念珠菌不易形成丝状体，但该物种很容易形成。虽然单种白色念珠菌生物膜已得到充分研究，但影响丝状形成（包括生物膜中的丝状形成）的念珠菌种间信号相互作用尚不清楚，我的初步数据表明白色念珠菌浮游细胞和生物膜都无法形成。在已建立的光滑念珠菌生物膜存在的情况下，白色念珠菌丝状化似乎是响应于发生的。光滑念珠菌分泌蛋白，因为当白色念珠菌浮游细胞和生物膜在独立生长的光滑念珠菌生物膜的上清液中生长时，观察到完全抑制，煮沸上清液时抑制活性消失，并且可以沉淀抑制因子我们的实验室之前已经表明，UME6（一种关键的细丝特异性转录）的组成型高水平表达。调节剂，足以产生几乎完整的丝状群体，驱动增加的生物膜形成并有意促进毒力，基于这些，光滑念珠菌生物膜产生的因子也完全抑制白色念珠菌 UME6 驱动的丝状形成。结果，我的假设是光滑念珠菌生物膜产生的白色念珠菌丝化抑制剂是一种分泌因子，作用于下游为了检验这一假设，本提案中的实验旨在：1) 确定光滑念珠菌生物膜产生的白色念珠菌丝化抑制剂的身份，2) 确定光滑念珠菌生物膜的作用。生产要素发挥作用 抑制白色念珠菌 UME6 表达菌株以及白色念珠菌临床口腔分离株的毒力特性这些研究意义重大，因为它们将为控制白色念珠菌丝状化的念珠菌种间信号相互作用提供重要的新见解。由于丝状化在白色念珠菌口腔组织侵袭、生物膜形成和发病机制中发挥着重要作用，这些研究可能会提供导致人类口腔真菌病原体的信息。开发新颖且更有效的抗真菌疗法来治疗口腔念珠菌病。