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Analysis of Apoptosis in Zebrafish Embryos by Whole-mount Immunofluorescence to Detect Activated Caspase 3
Published on: December 20, 2013
Apoptosis-like cell death induced by Salmonella in Acanthamoeba rhysodes
Ye Feng1, Yi-Hsing Hsiao, Hsiu-Ling Chen
1James D. Watson Institute of Genome Sciences, Zhejiang University, Hangzhou, China.
Abstract:
Free-living amoebae act as environmental hosts of several intracellular pathogens. We examined the interaction between Acanthamoeba rhysodes and Salmonella, a human intracellular pathogen. There was no difference among three different serovars of Salmonella in terms of their growth within A. rhysodes over time. The number of intracellular bacteria increased at 6 h post-infection, and the viability of A. rhysodes was significantly reduced at 24 h post-infection. Amoebic cell death was characterized by TUNEL and Annexin V assay, without DNA ladder identified, indicating an apoptosis-like cell death in Salmonella-infected A. rhysodes. Global gene expression screening between intracellular and extracellular Salmonella by microarray and quantitative PCR showed that genes from Salmonella pathogenicity islands and virulence plasmid were up-regulated within A. rhysodes. The phase-dependent expression pattern suggests their distinct roles in the pathogenesis. A. rhysodes and Salmonella provide a model to study transient symbiosis between bacterial pathogens and protozoa in an aquatic ecosystem.
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