Effect Of NDVcc,NDVsp And Its HN/F Protein On HeLa Cells

Effect of NDVco~ NDVsp and its UN/F Protein on HeLa cells Luo qinfang The Newcastle disease virus (NDV),a member of the Paramyxoviridae family infects all kinds of birds. the virus particle contain two surface spike glycoproteins, the hemagglutinin-neuraminidase(HN)and the fusion protein (F).The FIN protein mediates attachment of virions to sialic acid-containing receptor molecules and also has receptor-destroying activity. The F protein functions in penetration of virus into the host cell by mediating fusion of the virion envelope with the cellular plasma mambrane. Previous study showed that many kinds of tumor cells could be killed by NDV, but the anti-tumor mechanism of NDV remains unknown. In order to study the effection of NDV and the FIN/F glycoprotein of the virus on Hela cells, 2 strains of NDV, an avirulent Changchun strain and virulent Siping strain were choosen, and 2 eukaryotic expression plasmids pIRHNc, pIRHNs which could express the FIN protein of Changchun strain. Siping Strain respectively, were constructed by putting the respective UN gene of the 2 strains downstream of the CMV promoter in the expression vector pIRES1, and another expression plasmid that expressing the F and FIN protein of Changchun strain was constructed by puffing the FIN gene downstream of the CMV promoter and with the neo gene replaced by the F gene as well. After infection of Hela cell with the 2 strains of NDV, the cells were harvested at 24h, 48h, 72h and 96h postinfection, CPE was observed and then the cell were stained by Acrodine orange and the P53 ,bcl-2 level were analysed, finally the cell genome were extracted and analysed by agrose gel 56 1~~R HNIF ~4 HeLa~l~{~1 electrophoresis. Another experiment was performed by transfecting Hela cells with the 2 constructed plasmids pIRI-lNc, pIRH7Ns, and selected transfected cell with G418. The expression of the UN protein were identified by indirect IFA ,SD S-PAGE and Western blot with respective antibodies against HN protein. The transfected cells were also observed/harvested and analysed as described above. The results indicated that the 1-IN proteins of the 2 NDV strains were expressed mostly on the surface of the transfected cells by the constructed plasmids, and the expression amount of HN protein of nonselected cells reached peak at 72h postinfection, but was a little lower than that of the G4 18 selected. The expressed UN protein showed hemagglutination activity as well. The characteristic of cell death induced by the Changchun strain and Siping strain was different ,but no differences were observed before and after infectionltransfection of the Hela cells on the P53, bcl-2 level. The cell genome degradation were observed after expression of UN protein of Changchun sWain but not Siping strain in Hela cells. Those study laid the foundation of further investigation of the NDV anti-tumor mechanism.