Three-dimensional analysis and modeling of the Chlamydia developmental cycle

衣原体发育周期的三维分析和建模

• 批准号: 9035928
• 负责人: Ming Tan
• 金额: $ 18.44万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-01 至 2018-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9035928
• 关键词: Area; Bacteria; Binding; Body Size; Cell Fate Control; Cells; Centers for Disease Control and Prevention (U.S.); Chlamydia; Chlamydia Infections; Communicable Diseases; Computing Methodologies; Confocal Microscopy; Crowding; Data; Data Analyses; Development; Developmental Process; Disease Notification; Electron Microscopy; Environment; Equilibrium; Event; Future; Genital system; Hour; Human; Image; Individual; Infection; Infectious Agent; Location; Lung diseases; Membrane; Modeling; Process; Production; Property; Public Health; Regulation; Reporting; Scanning; Scanning Electron Microscopy; Sexually Transmitted Diseases; Surface; Therapeutic; Thick; Three-Dimensional Image; Three-dimensional analysis; Time; base; extracellular; genital infection; innovation; mathematical model; microscopic imaging; monolayer; novel; novel strategies; pathogen; pathogenic bacteria; public health relevance; rate of change; reconstruction; three-dimensional modeling

 DESCRIPTION (provided by applicant): Chlamydia is one of the most important infectious agents from a public health perspective. In 2011 more than 1.4 million cases of chlamydial infections were reported to the CDC making it the most commonly reported infectious disease in the U.S. Chlamydia causes an intracellular infection that is unusual among pathogenic bacteria because it involves conversion between two specialized forms of the bacterium. The reticulate body (RB) is an intracellular form that replicates by binary fission, while the elementary body (EB) is the infectious form that can transmit the infection to a new cell. A successful infectious cycle involves both RB replication and RB-to-EB conversion within an intracellular compartment called the chlamydial inclusion, but it is not known how these processes are regulated. We have developed an innovative approach to obtain detailed three dimensional views of a Chlamydia-infected cell. We first perform electron microscopy imaging on serial sections through the cell, then use computational methods to reconstruct these scans into a 3D image and finally trace the outline of each of the bacteria. With this approach we can visualize the entire chlamydial inclusion and the numbers and locations of all the RBs and EBs. In Aim 1 of this application, we propose to obtain and compare 3D reconstructions of Chlamydia-infected cells over the course of the 48-hour developmental cycle. In Aim 2, we will analyze this data with mathematical and modeling approaches to determine if the proportion of RBs that are replicating or converting changes with time. We will also examine if RB replication and RB-to-EB conversion correlate with external factors such as the size of the inclusion or the surface area of the inclusion membrane. This novel approach will provide an unprecedented level of quantitative and spatial detail about a Chlamydia-infected cell. This information will help us to understand fundamental properties about the intracellular infection, including how this important pathogen replicates and produces infectious progeny inside a human cell.

 描述（由申请人提供）：从公共卫生角度来看，衣原体是最重要的传染源之一。2011年，超过140万例衣原体感染病例报告给CDC，使其成为美国最常报告的传染病。衣原体引起的细胞内感染在致病菌中是不寻常的，因为它涉及两种特殊形式的细菌之间的转换。网状体（RB）是一种通过二分裂复制的细胞内形式，而基本体（EB）是可以将感染传播到新细胞的感染形式。一个成功的感染周期涉及RB复制和RB到EB的转换在细胞内隔室称为衣原体包涵体，但它是不知道这些过程是如何调节。我们已经开发出一种创新的方法来获得详细的三维视图的衣原体感染的细胞。我们首先对细胞的连续切片进行电子显微镜成像，然后使用计算方法将这些扫描重建成3D图像，最后追踪每个细菌的轮廓。通过这种方法，我们可以可视化整个衣原体包含物以及所有RB和EB的数量和位置。在本申请的目的1中，我们提出在48小时发育周期的过程中获得并比较衣原体感染细胞的3D重建。在目标2中，我们将使用数学和建模方法分析这些数据，以确定复制或转换的RB的比例是否随时间而变化。我们还将检查RB复制和RB到EB的转化是否与外部因素相关，如夹杂物的大小或夹杂物膜的表面积。这种新方法将提供有关衣原体感染细胞的前所未有的定量和空间细节水平。这些信息将帮助我们了解细胞内感染的基本特性，包括这种重要的病原体如何在人类细胞内复制和产生感染性后代。