Owing to the rapidly increasing output of nano-scale titanium dioxide(TiO2) particles,their potential risk for central nerve system(CNS) has elicited much concern recently.Microglia is the resident macrophage in CNS a...Owing to the rapidly increasing output of nano-scale titanium dioxide(TiO2) particles,their potential risk for central nerve system(CNS) has elicited much concern recently.Microglia is the resident macrophage in CNS and essential for the homeostasis of the CNS microenvironment.They are supposed to response to nanoparticles depositing in the brain tissues.Therefore,we investigated the cytotoxic effects of TiO2 NPs on microglia N9 cells in vitro.Results of propidium iodide/fluorescein diacetate(PI/FDA) double staining and MTT test clearly showed that TiO2 NPs more efficiently affected the viability of microglia N9 cells.Further Hoechst 33258 staining and flow cytometric analysis proved that nano-scale but not normal scale TiO2 induced apoptosis in vitro.These data suggest that TiO2 NPs can elicit apoptosis of N9 cells in vitro and thus present a potential risk for CNS.展开更多
A novel avian influenza A(H7N9) virus recently emerged in the Yangtze River delta and caused diseases, often severe, in over 130 people. This H7N9 virus appeared to infect humans with greater ease than previous avian ...A novel avian influenza A(H7N9) virus recently emerged in the Yangtze River delta and caused diseases, often severe, in over 130 people. This H7N9 virus appeared to infect humans with greater ease than previous avian influenza virus subtypes such as H5N1 and H9N2. While there are other potential explanations for this large number of human infections with an avian influenza virus, we investigated whether a lack of conserved T-cell epitopes between endemic H1N1 and H3N2 influenza viruses and the novel H7N9 virus contributes to this observation. Here we demonstrate that a number of T cell epitopes are conserved between endemic H1N1 and H3N2 viruses and H7N9 virus. Most of these conserved epitopes are from viral internal proteins. The extent of conservation between endemic human seasonal influenza and avian influenza H7N9 was comparable to that with the highly pathogenic avian influenza H5N1. Thus, the ease of inter-species transmission of H7N9 viruses(compared with avian H5N1 viruses) cannot be attributed to the lack of conservation of such T cell epitopes. On the contrary, our findings predict significant T-cell based cross-reactions in the human population to the novel H7N9 virus. Our findings also have implications for H7N9 virus vaccine design.展开更多
基金Supported by the German Academic Exchange Service (DAAD) and Chinese Scholarship Council (CSC)
文摘Owing to the rapidly increasing output of nano-scale titanium dioxide(TiO2) particles,their potential risk for central nerve system(CNS) has elicited much concern recently.Microglia is the resident macrophage in CNS and essential for the homeostasis of the CNS microenvironment.They are supposed to response to nanoparticles depositing in the brain tissues.Therefore,we investigated the cytotoxic effects of TiO2 NPs on microglia N9 cells in vitro.Results of propidium iodide/fluorescein diacetate(PI/FDA) double staining and MTT test clearly showed that TiO2 NPs more efficiently affected the viability of microglia N9 cells.Further Hoechst 33258 staining and flow cytometric analysis proved that nano-scale but not normal scale TiO2 induced apoptosis in vitro.These data suggest that TiO2 NPs can elicit apoptosis of N9 cells in vitro and thus present a potential risk for CNS.
基金supported in part by General Research Fund, Research Grants Council of Hong Kong (HKU 780113M)Area of Excellence program (AoE/M-12/06)+1 种基金University Grants Committee of Hong Kong SARResearch Fund for the Control of Infectious Diseases, Hong Kong SAR government (11100742)
文摘A novel avian influenza A(H7N9) virus recently emerged in the Yangtze River delta and caused diseases, often severe, in over 130 people. This H7N9 virus appeared to infect humans with greater ease than previous avian influenza virus subtypes such as H5N1 and H9N2. While there are other potential explanations for this large number of human infections with an avian influenza virus, we investigated whether a lack of conserved T-cell epitopes between endemic H1N1 and H3N2 influenza viruses and the novel H7N9 virus contributes to this observation. Here we demonstrate that a number of T cell epitopes are conserved between endemic H1N1 and H3N2 viruses and H7N9 virus. Most of these conserved epitopes are from viral internal proteins. The extent of conservation between endemic human seasonal influenza and avian influenza H7N9 was comparable to that with the highly pathogenic avian influenza H5N1. Thus, the ease of inter-species transmission of H7N9 viruses(compared with avian H5N1 viruses) cannot be attributed to the lack of conservation of such T cell epitopes. On the contrary, our findings predict significant T-cell based cross-reactions in the human population to the novel H7N9 virus. Our findings also have implications for H7N9 virus vaccine design.
