title: Necrotic Response to Low Pathogenic H9N2 Influenza Virus in Chicken Hepatoma Cells.
abstract: BACKGROUND
  Limited knowledge about the molecular mechanism of avian influenza H9N2 virus pathogenicity in birds as well as human hosts has limited the development of effective control against the disease. To overcome this issue detailed understanding of the infectious characteristics of the virus in host cells should be obtained.
  
  
  OBJECTIVE
  In this study we examined the replication kinetics of H9N2 virus in a chicken hepatoma cell line to obtain insight into the pathogenesis of H9N2 viruses.
  
  
  METHODS
  The kinetic replication of H9N2 influenza virus in chicken hepatoma and fibroblastic cells was studied in the presence and absence of supplemental trypsin. High viral titers observed in liver cells in a short time correlated with the degree of cytopathic effects. To determine whether the ultimate outcome of infection results in programmed cell death, the infected cells were observed by the cell viability assay, DNA fragmentation, caspase cascade activation, and quantified lactate dehydrogenase release.
  
  
  RESULTS
  The degree of viability was significantly reduced in infected hepatoma cells. Observations of caspase activation and cell DNA laddering in infected cells were not indicative of apoptosis. The infected hepatoma cells released lactate dehydrogenase, which is consistent with cell death by necrosis.
  
  
  CONCLUSIONS
  Taken together, these data reveal that cellular protease of chicken liver cells allows the replication of high yields of H9N2 virus in the absence of trypsin and also cell death in the infected cells is due to necrosis.
authors: Razi Vaccine and Serum Research Institute, Karaj, IR Iran.
authors: Seyedeh Zahra
authors: SZ
authors: Mosavi
authors: Razi Vaccine and Serum Research Institute, Karaj, IR Iran.
authors: Shahla
authors: S
authors: Shahsavandi
authors: Razi Vaccine and Serum Research Institute, Karaj, IR Iran.
authors: Mohammad Majid
authors: MM
authors: Ebrahimi
authors: Razi Vaccine and Serum Research Institute, Karaj, IR Iran.
authors: Ali Reza
authors: AR
authors: Hatami
authors: Razi Vaccine and Serum Research Institute, Karaj, IR Iran.
authors: Kaveh
authors: K
authors: Sadeghi
authors: Social Security Hospital, Khorram Abad, IR Iran.
authors: Hassan
authors: H
authors: Shahivandi
keywords: Hepatoma; Influenza Virus; Necrosis