Bacterial internalization may actually benefit the host by serving as a defense mechanism. Invasive strains cause disease ( 11), but the role of invasion in the pathogenic process is unclear. Although considered a primarily extracellular pathogen, some clinical and laboratory isolates are internalized by epithelial cells ( 11, 12, 14).
Pseudomonas aeruginosa is an important nosocomial pathogen with an impressive arsenal of secreted and cell-associated virulence factors ( 42). This finding suggests that the ability to resist internalization may be important for virulence in vivo. In a mouse model of acute pneumonia, PA103ΔUΔT reached the lungs as efficiently as PA103ΔU but showed reduced colonization of the liver. Cell fractionation experiments showed that ExoT is translocated into host cells and that mutation of the arginine finger did not disrupt translocation. Mutation of the conserved arginine in ExoT diminished its anti-internalization activity and altered its ability to disrupt the actin cytoskeleton. ExoT contains a signature arginine finger domain found in GTPase-activating proteins. ExoS, which is closely related to ExoT but has additional ADP-ribosylating activity, can substitute for ExoT as an anti-internalization factor. In this work we show that the type III secreted protein ExoT inhibits the internalization of PA103 by polarized epithelial cells (Madin-Darby canine kidney cells) and J774.1 macrophage-like cells. Analyses of mutants suggest that PA103 delivers a negative regulator of invasion, or anti-internalization factor, to host cells via a type III secretion system.
Previous studies demonstrated that the lung-virulent strain PA103 has the capacity to be either cytotoxic or invasive. Người sử dụng của Frame Maker Pro đánh giá xếp hạng 4 trong số 5 sao.Pseudomonas aeruginosa, an important nosocomial pathogen of humans, expresses a type III secretion system that is required for virulence. įrame Maker Pro đã chạy trên hệ điều hành sau: Windows. Phiên bản mới nhất của Frame Maker Pro là 3.91, phát hành vào ngày. Tổng quanįrame Maker Pro là một Shareware phần mềm trong danh mục Ứng dụng đồ họa được phát triển bởi AMS Software. You can create hundreds of original and creative frames and save these frames as presets. Through its innovative graphical user interface, you can choose from a variety of frames and add them to your images full screen preview the result save your framed images in popular formats for use on your projects print your framed images. Frame Maker Pro is an imaging and desktop enhancement program that adds impressive frames to digital photos in order to enhance your personal albums, projects, websites or desktop wallpapers with remarkable ease.
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