Project description:Naegleriavirus virions purified from the amoeboflagellate Naegleriaclarki were analysed. The virus infects members of the genus Naegleriaincluding the infamous human pathogen Naegleria fowleri, the causativeagent of the rare but lethal disease primary amoebicmeningoencephalitis.
Project description:Naegleria fowleri, the causative agent of primary amoebic meningoencephalitis (PAM), requires increased research attention due to its high lethality and the potential for increased incidence as a result of global warming. The aim of this study was to investigate the interactions between N. fowleri and host cells in order to elucidate the mechanisms underlying the pathogenicity of this amoeba. A co-culture system comprising human fibrosarcoma cells was established to study both contact-dependent and contact-independent cytopathogenicity. Proteomic analyses of the amoebas exposed to human cell cultures or passaged through mouse brain were used to identify novel virulence factors. Our results indicate that actin dynamics, regulated by Arp2/3 and Src kinase, play a considerable role in amoeba cell ingestion. We have identified three promising candidate virulence factors, namely lysozyme, cystatin and hemerythrin, which may be critical in facilitating N. fowleri evasion of host defenses, migration to the brain and induction of a lethal infection. Long-term co-culture secretome analysis revealed an increase in protease secretion, which enhances N. fowleri cytopathogenicity. Raman microspectroscopy revealed significant metabolic differences between axenic and brain-isolated amoebae, particularly in lipid storage and utilization. Taken together, our findings provide important new insights into the pathogenic mechanisms of N. fowleri and highlight potential targets for therapeutic intervention against PAM.
Project description:We have isolated and characterized the extracellular vesicles released by Naegleria fowleri (ATCC 30808) and determined their effect on MDCK cells and erythrocytes.
Project description:We report the application of high-throughput RNA sequencing technology to examine expression profiling of plasma transfer RNA (tRNA)-derived small RNAs (tsRNAs) in children with fulminant myocarditis during acute phase (FM-A group), children with fulminant myocarditis during convalescent phase (FM-C group), and healthy volunteers (Con group). A total of 750 precisely matched tsRNAs were identified in the plasma from the three groups. We find that a total of 13 tsRNAs were differentially expressed in FM-A and CON samples, of which 11 tsRNAs were upregulated and 2 were downregulated, and 694 tsRNAs were excluded ; a total of 8 tsRNAs were differentially expressed in paired FM-C and CON samples, of which 2 tsRNAs were upregulated and 6 were downregulated and 703 tsRNAs were excluded . This study provides new ideas for future research on elucidating the mechanisms of myocarditis through regulating tsRNAs levels.