Investigating a signaling molecule that cooperates with quorum sensing to induce biofilm formation in C. neoformans

研究与群体感应配合诱导新型隐球菌生物膜形成的信号分子

• 批准号: 10550504
• 负责人: Xiaorong Lin
• 金额: $ 22.65万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-11-25 至 2024-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10550504
• 关键词: Adhesions; Affect; Ascomycota; Bacterial Adhesins; Basidiomycota; Behavior; Candida; Cell surface; Clinical; Communicable Diseases; Communication; Communities; Complex; Coupling; Cryptococcus; Cryptococcus neoformans; Environment; Farnesol; Foundations; Future; Gene Deletion; Gene Expression; Gene Targeting; Genes; Genetic; Goals; HIV/AIDS; Homologous Gene; Human; Intercellular Communication Process; Investigation; Knowledge; Laboratories; Mass Spectrum Analysis; Mating Types; Meningoencephalitis; Microbe; Microbial Biofilms; Microbiology; Modeling; Mutagenesis; Mutation; Nature; Opportunistic Infections; Partner in relationship; Pathogenesis; Pathway interactions; Peptides; Persons; Pheromone; Prevalence; Process; Production; Proteins; Public Health; Regulation; Research; Role; Saccharomyces; Signal Induction; Signal Transduction; Signaling Molecule; Signaling Protein; Specificity; Structural Protein; Structure; System; T-DNA; Transcription Repressor; Work; congenic; fast protein liquid chromatography; fungus; gene discovery; in vivo; insight; intercellular communication; microbial community; mutant; novel; overexpression; pathogenic fungus; prevent; quorum sensing; response; transcription factor; transcriptome

ABSTRACT The objectives of this exploratory R21 proposal are to identify and characterize an intercellular communication signal that induces biofilm formation in cooperation with quorum sensing in the human fungal pathogen Cryptococcus neoformans. C. neoformans is a basidiomycetous fungus that causes cryptococcal meningoencephalitis (CME), one of the most fatal and common opportunistic infections affecting people with HIV/AIDS. Like many other infectious microbes, C. neoformans forms biofilm-like structures known as cryptococcoma in vivo. However, we know very little about the structural requirements for biofilms or their genetic regulation in this fungal pathogen, partly because Cryptococcus forms biofilms poorly under laboratory conditions, and partly because this basidiomycete does not carry homologues of any known biofilm-relevant proteins established in ascomycetes like Saccharomyces and Candida species. Here we found that disruption of a transcription repressor Ssn6 in a mating-type a strain, but not in the congenic mating-type α strain, leads to robust biofilm formation in C. neoformans, which provides an entry point for us to investigate genetic regulation of biofilm formation in this fungus. Interestingly, ssn6a biofilm colonies induce the nearby ssn6α colonies to also form biofilms and this process is independent of the mating pheromone. We discovered that the intercellular communication system which activates biofilm formation requires the quorum-sensing molecule Qsp1 and an unknown peptide-based signaling molecule. Here we propose to (1) identify the secreted biofilm signaling molecule and (2) elucidate the pathway involved in biofilm formation activated by this signaling molecule. The proposed work is expected to yield insights into this layered communication system that regulates such complex community behaviors in a clinically important fungal pathogen. We also expect to identify novel biofilm structural proteins like adhesins in Cryptococcus in this process, which will fill the critical gap in our knowledge about biofilm formation and regulation in basidiomycetes. The findings from this exploratory research will also provide a foundation for future investigation of the impact of biofilm regulation on cryptococcal pathogenesis.

抽象的 此探索性R21提案的目标是识别和表征细胞间通信 与人类真菌病原体中的法定感应合作诱导生物膜形成的信号 加密赛车。 C. Neoformans是一种碱性真菌，会导致隐球菌 脑膜脑炎（CME），这是影响患者患者的最致命，最常见的机会感染之一 艾滋病毒/艾滋病。像许多其他感染性微生物一样，新外形梭菌形成了类似生物膜的结构 体内隐孢菌。但是，我们对生物膜及其的结构要求一无所知 这种真菌病原体中的遗传调节，部分是因为在实验室下形成的生物膜形成较差的生物膜 条件，部分是因为这种碱性菌不能携带任何已知生物膜的同源物 蛋白质在糖果和念珠菌等子囊菌中建立。 在这里，我们发现在交配型A菌株中的转录复制品SSN6的破坏，但不在 先天性交配型α菌株，导致C. neoformans中稳健的生物膜形成，它提供了进入 我们研究了这种真菌中生物膜形成的遗传调节。有趣的是，SSN6A生物膜 菌落诱导附近的SSN6α菌落也形成生物膜，此过程与交配无关 信息素。我们发现激活生物膜形成的细胞间通信系统 需要群体感应分子QSP1和未知的基于肽的信号分子。我们在这里 提议（1）确定分泌的生物膜信号分子，（2）阐明与生物膜有关的途径 该信号分子激活的形成。预计拟议的工作将对这种分层产生见解 在临床上重要的真菌中调节这种复杂社区行为的沟通系统 病原。我们还期望鉴定出新型的生物膜结构蛋白，例如在此中加密环球中的粘附 过程，这将填补我们对生物膜形成和调节的了解的关键差距 碱性菌。这项探索性研究的发现还将为未来提供基础 研究生物膜调节对隐球菌发病机理的影响。