125 research outputs found

    Optical tracking of bacterial immune phagocytosis based on acid-responsive probes

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    细菌感染与免疫杀死代表着病原体与宿主相互关系中很重要的两个方面,研究细菌感染与免疫反应的关系,有助于对病原体致病机理的理解。吞噬作用作为生命体防御感染的一道防线,是最古老的,也是最基本的防卫机制之一。吞噬细胞通过吞噬感染的细菌形成吞噬体,随后吞噬体逐渐与溶酶体融合形成吞噬溶酶体。溶酶体是细胞的消化器官,其内部pH为4~5,含有各种水解酶。细菌在吞噬溶酶体内被酸性pH及水解酶的协同作用降解杀死。 细胞吞噬作用异常则会导致机体的免疫功能缺陷,从而引发一系列的疾病。能够实时追踪细菌吞噬作用的过程对于研究病原微生物的致病机理具有重要意义。目前研究中常利用荧光素标记的乳胶粒子、绿色荧光蛋白(GFP)转...Bacterial infection and immunological eradiation are two key aspets of hosts-pathogen interplay. A precise understanding of host-pathogen interaction is critical for treatment variety of infectious diseases. Phagocytosis is an effective anti-bacteria defense. Phagocytes engulf bacteria to the phagosomes, which then fuse with lysosomes to form phagolysosomes. Lysosomes are the digestive organelle o...学位:理学硕士院系专业:化学化工学院_化学生物学学号:2052013115167

    Role of Bacterial Exopolymers and Host Factors on Adherence and Phagocytosis of Staphylococcus aureus in Foreign Body Infection

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    Using a previously developed guinea pig model of foreign body infection, we examined ultrastructural and functional surface alterations of Staphylococcus aureus strain Wood 46 during the early phase of infection. Exopolymer-free bacteria were prepared and inoculated into subcutaneously implanted tissue cages. After three hours, the bacteria showed abundant capsular and intercellular exopolymers, which were visualized by transmission electron microscopy. Exopolymers were also produced by S. aureus exposed in vitro to fluid from the tissue cage. In contrast, human serum albumin prevented exopolymer production by S. aureus. The influence of exopolymers on the susceptibility of S. aureus to ingestion and phagocytic killing by neutrophils was tested in vitro and found to be negligible. Furthermore, adherence of S. aureus to fibronectin-coated surfaces was unaffected by the presence or absence of exopolymers. Thus, in our experimental model, exopolymers are produced early during the onset of infection, but they have little impact on adherence and phagocytosi
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