The Infection And Pathogenesis Of A New 2009 Pandemic Strain In China

The2009pandemic A/Wenshan/01/2009H1N1induces apoptotic cell death in human airway epithelial cellIn2009, a novel swine-origin H1N1influenza virus emerged first in Mexico and quickly spread to other countries and areas, including China. This2009pandemic H1N1can cause human respiratory disease, but the understanding of its pathogenesis remains incomplete. Here we studied the infection and pathogenesis of a new2009pandemic strain in China (A/Wenshan/01/2009H1N1), in human airway epithelial cell lines compared with contemporary seasonal H1N1influenza virus. Our results showed virus infection of A/Wenshan H1N1induced significant apoptotic cell death in both human nasopharyngeal carcinoma cell line CNE-2Z and human lung adenocarcinoma cell line A549. The A/Wenshan H1N1virus enters both of these cell types more efficiently than the seasonal influenza virus. Viral entry in both cell lines was shown to be mediated by clathrin-and dynamin-dependent endocytosis. Therefore, we first discovered that a2009pandemic H1N1strain, A/Wenshan/1/2009could induce apoptotic cell death in epithelial cells of human respiratory tract, suggesting a molecular pathogenesis for2009pandemic H1N1.Phosphatidylinositol4-Kinase â…¢ beta is required for Severe Acute Respiratory Syndrome Coronavirus Spike-Mediated Cell EntryPhosphatidylinositol kinases (PI kinases) play an important role in the life cycle of several viruses after infection. Using gene knockdown technology, we demonstrate that phosphatidylinositol4-kinase â…¢ beta (PI4KB) is required for cellular entry by pseudoviruses bearing the SARS-CoV spike protein and that the cell entry mediated by SARS-CoV S is strongly inhibited by knockdown of PI4KB. Consistent with this observation, pharmacological inhibitors of PI4KB blocked entry of SARS pseudovirions. Further research suggested that PI4P plays an essential role in SARS-CoV S-mediated entry, which is regulated by the PI4P lipid microenvironment. We further demonstrate that PI4KB does not affect virus entry at the SARS-CoV S-ACE2binding interface or at the stage of virus internalization, but rather at or before virus fusion. Taken together, these results indicate a new function for PI4KB and suggest a new drug target for preventing SARS-CoV infection.Neutralizing antibodies induced by SARS-CoV DNA plasmid immunizationSevere acute respiratory syndrome (SARS) is caused by a SARS-associated coronavirus (SARS-CoV), with a mortality rate of approximately10%(1-3). It continues to be potential for future zoonotic transmission events, leading to the reintroduction of SARS-CoV into human population, for which there is no effective treatment. Neutralizing antibodies are a promising field for treatment with deadly disease induced by virus infection. And neutralizing antibodies have shown potential in the treatment of retroviral infections. Professionals in the field have used HIV treatment as an example of infections these antibodies can treat. Recently, potent and broadly neutralizing human antibodies against influenza (such as CR6261) have been reported. The severe acute respiratory syndrome-associated coronavirus (SARS-CoV) spike protein (S) is a major target for neutralizing antibodies. Previous studies focused on producing antibodies using purified virus protein or peptides. Although it was proved to be an effective method, it also took a long time to prepare the antigens. Some other methods such as phage display also required much work preparing libraries. Here, we used DNA plasmid encoding SARS-CoV spike protein segment-S1190and immunized mouse in several weeks. Then we can get high amount of antibodies reacting with spike protein. Future studies demonstrated antibodies induced by DNA plasmid can strongly neutralize SARS pseudovirus entry into ACE2expression cells. Although antibodies induced can't be directly used as therapeutic drugs, it still can be applied to detection field.