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HN protein of Newcastle disease virus sensitizes HeLa cells to TNF-α-induced apoptosis by downregulating NF-κB expression

Rajmani, R. S., Gupta, Shishir Kumar, Singh, Prafull Kumar, Gandham, Ravi Kumar, Sahoo, A. P., Chaturvedi, Uttara, Tiwari, Ashok K.
Archives of virology 2016 v.161 no.9 pp. 2395-2405
Newcastle disease virus, apoptosis, cell viability, hemagglutinins, membrane proteins, sialidase, transcription factor NF-kappa B, tumor necrosis factor-alpha
Hemagglutinin neuraminidase (HN) is a membrane protein of Newcastle disease virus (NDV) with the ability to induce apoptosis in many transformed cell lines. TNF-α is a multi-factorial protein that regulates cell survival, differentiation and apoptosis. In a previous study, we reported that HN protein induces apoptosis by downregulating NF-κB expression. Further, we speculated that downregulation of NF-κB expression might sensitize HeLa cells to TNF-α-mediated apoptosis. Therefore, the present study was undertaken to investigate if HN protein could sensitize HeLa cells to TNF-α and to examine the apoptotic potential of the HN protein and TNF-α in combination. The results revealed that the pro-apoptotic effects were more pronounced with the combination of HN and TNF-α than with HN or TNF-α alone, which indicates that the HN protein indeed sensitized the HeLa cells to TNF-α-induced cell death. The results of the study provide a mechanistic insight into the apoptotic action of HN protein along with TNF-α, which could be valuable in treating tumor types that are naturally resistant to TNF-α.