Analysis of the mechanism of cell cycle-dependent virus infection and cellular response

1. To understand whether influenza virus infection is cell cycle dependent or not，我们开发了microchip chamber system combined with optical trapping of single virus. Using thissystem,the fluorescently labeled influenza virus was successfully trapped under the lens using 1064nmlaser. The trapped influenza病毒was transported on The dividing cell and released on it，but influenza virus did not attached. The same unattached virus on The dividing cell was trappedagain and transported to the resting cell and released on it，the virus attached on the resting cell. This result encouraged us to识别the differencebetween the resting and dividing cells. At first，我们tried to compare the 2,3-sialic acid contents between both cells. the result indicated that thecontent of 2,3-sialic acid is higher in the resting cells than in the dividing cells.2. Hostprotein Ebp1, ErbB3 binding protein，interacted with PB1 subunit of influenza virus RNA dependent RNA polymeraseinhibited the RNA synthesis in vitro but not endonuclease associated with RNA dependent RNApolymerase. Interestingly Ebp1 expression was induced by influenza virus infection. To understandthe induction mechanism of Ebp1 expression by influenza virus infectiondifferent combination among the 8 viral protein expression plasmids and viral RNA （vRNA）expression plasmid were transfected into the cell and assayed the Ebp1 expression level usingRT-PCR. The result indicated that The expression of vRNP complex, vRNA，influenza virus RNA dependent RNA polymerase and NPInfluenza virus infection induced changing of the cellular Influenza virus infection induced changing of the cellularmembrane strength。

1. To understand whether influenza virus infection is cell cycle dependent or not, we developed the microchip chamber system combined with optical trapping of single virus. Using this system, the fluorescently labeled influenza virus was successfully trapped under the lens using 1064 nm laser. The trapped influenza virus was transported on the dividing cell and released on it, but influenza virus did not attached. The same unattached virus on the dividing cell was trapped again and transported to the resting cell and released on it, the virus was attached on the resting cell. This result encouraged us to identify the difference between the resting and dividing cells. At first, we tried to compare the ・ 2,3-sialic acid contents between both cells. The result indicated that the content of ・ 2,3-sialic acid is higher in the resting cells than in the dividing cells.2. Host protein Ebp1, ErbB3 binding protein, interacted with PB1 subunit of influenza virus RNA dependent RNA polymerase, and inhibited the RNA synthesis in vitro but not endonuclease associated with RNA dependent RNA polymerase. Interestingly Ebp1 expression was induced by influenza virus infection. To understand the induction mechanism of Ebp1 expression by influenza virus infection, the different combination among the eight viral protein expression plasmids and viral RNA (vRNA) expression plasmid were transfected into the cell and assayed the Ebp1 expression level using RT-PCR. The result indicated that the expression of vRNP complex, vRNA, influenza virus RNA dependent RNA polymerase and NP, influenced the Ebp1 expression. 3. Influenza virus infection induced changing of the cellular membrane strength.