title: Transcriptional adaptation of Shigella flexneri during adherence to epithelial cells.
abstract: Shigella adhesion to host cells is a transitional stage from an extracellular to an intracellular environment. However, the dynamic adaptations of Shigella during adhesion are poorly understood. To address this, we performed the first transcriptome analysis of Shigella flexneri 2457T during adhesion. A total of 1,757 genes were differentially regulated (>twofold). The majority of plasmid-borne ipa-mxi-spa locus genes were downregulated, indicating these virulence genes were strictly regulated after successful adhesion. Altered expression of genes involved in stress response indicates that adherent S. flexneri encountered envelope stress and oxidative stress. Shigella flexneri also experienced reduced energy production during adherence. Transcript profiling and cell culture assays using glpD and glpK mutants showed that enhancement of glycerol catabolism were related with adhesion ability of S. flexneri. In addition, regulation of expression of some ionic transport system may be required for S. flexneri adhesion. Expression levels of 26 genes were further examined using qRT-PCR, which were congruent with transcriptome data. A comparison with expression profile during intracellular growth revealed major differences in genes involved in translation, surface modification, and utilization of carbon and iron. These results contribute to the knowledge of the adaptation mechanisms of S. flexneri during adhesion.
authors.affiliation: TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China; The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Ni
authors.forename: Lingyan
authors.initials: L
authors.lastname: Jiang
authors.forename: Lu
authors.initials: L
authors.lastname: Feng
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics*; D000942:Antigens, Bacterial / Q000235:genetics; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D004847:Epithelial Cells / Q000382:microbiology*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005990:Glycerol / Q000378:metabolism; D005993:Glycerolphosphate Dehydrogenase / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D007501:Iron / Q000378:metabolism; D009154:Mutation; D018384:Oxidative Stress / Q000235:genetics; D010957:Plasmids; D014176:Protein Biosynthesis; D012763:Shigella flexneri / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology*; D014774:Virulence / Q000235:genetics
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C063664:IpaA protein, Shigella flexneri; D002244:Carbon; D007501:Iron; D005993:Glycerolphosphate Dehydrogenase; C098831:glycerol-3-phosphate oxidase; D005990:Glycerol
keywords: Comparative transcriptome analysis; RNA-sequencing; Shigella attachment