ABSTRACT
<p><b>OBJECTIVE</b>To study the global evolutionary characteristics of hemagglutinin gene HA1 of influenza H1N1 infecting different species during 2000-2009.</p><p><b>METHODS</b>The target sequences were downloaded from NCBI and analyzed using bioinformatic software to construct the phylogenetic tree.</p><p><b>RESULTS</b>The HA1 amino acid sequences of influenza H1N1 contained four mutated antigenic sites and receptor-binding sites, and the novel influenza virus shared most of the mutated amino acid sites with swine H1N1 influenza virus.</p><p><b>CONCLUSION</b>The HA1 gene of novel influenza virus might originate from the early swine H1N1 influenza virus from North America, and in the evolutionary process, a number of important sites of HA1 gene mutated to result in the outbreak of influenza.</p>
Subject(s)
Humans , Antigenic Variation , China , Epidemiology , Computational Biology , Genes, Viral , Hemagglutinin Glycoproteins, Influenza Virus , Genetics , Influenza A Virus, H1N1 Subtype , Genetics , Influenza, Human , Epidemiology , Virology , Mutation , PhylogenyABSTRACT
<p><b>OBJECTIVE</b>To investigate the mechanisms for the cytopathic effect (CPE) of human cytomegalovirus (HCMV) in ECV304 endothelial-like cells.</p><p><b>METHODS</b>PCR and indirect immunofluorescence were used to detect HCMV infection by examining immediate-early (IE) gene and protein expression of the virus in ECV304 cells. Phase-contrast and electron microscopies were performed to observe the morphological changes of the infected and uninfected cells, and DNA ladder analysis and flow cytometry were carried out to study HCMV-induced cell apoptosis.</p><p><b>RESULTS</b>In HCMV-infected ECV304 cells, cytopathic effects were first observed at approximately 72 h post-infection. The cells with CPE changes exhibited detachment from the monolayer, cell rounding and shrinkage. The expression of the IE gene was detected. Chromatin condensation and nuclear fragmentation along with dramatic changes of the mitochondria were observed by electron microscopy at 96 h post-infection. Cellular DNA fragmentation was observed in the infected cells, which had cells apoptotic rates of 4.1% and 45.7% at 96 h and 144 h post-infection, respectively.</p><p><b>CONCLUSION</b>HCMV can induce apoptosis of ECV304 endothelial-like cells.</p>
Subject(s)
Humans , Antigens, Viral , Genetics , Metabolism , Apoptosis , Physiology , Cell Line , Cytomegalovirus , Genetics , Metabolism , DNA, Viral , Endothelial Cells , Cell Biology , Virology , Fluorescent Antibody Technique, Indirect , Immediate-Early Proteins , Genetics , Metabolism , Microscopy, Electron , Microscopy, Phase-Contrast , Polymerase Chain Reaction , Umbilical Veins , Cell Biology , VirologyABSTRACT
<p><b>OBJECTIVE</b>To observe the pathological changes and morphological alterations of ECV304 cells after the infection by herpes simplex virus type 2 (HSV-2) in vitro.</p><p><b>METHODS</b>Passaged ECV304 cells were infected with HSV-2, TCID50 and morphological changes were observed by optical microscopy and tissue staining.</p><p><b>RESULTS</b>One day after HSV-2 infection, swelling, rounding, and increase of thickened cytoplasmic granules occurred in the ECV304 cells, and on day 2, cell fusion was observed with weakened nuclear staining.</p><p><b>CONCLUSION</b>ECV304 cells mostly undergo necrosis after HSV-2 infection without obvious evidence of cell apoptosis.</p>