Infectious bursal disease virus mobilizes the apoptotic machinery to invade chicken embryo fibroblasts

Infectious Bursal Disease Virus (IBDV) primarily affects bursa of young birds. An in-vitro study was conducted in Chicken Embryo Fibroblast (CEF) cells. Seventy percent confluent CEF cells were infected with IBDV Im+ strain. Significant increase in apoptotic cells was observed in CEF cells 24-h-pi with IBDV Im+ strain and thereafter as revealed by TUNEL assay. Down regulation of Caspase 8 at 1 h pi with IBDV 1m+ strain evidence the inhibition of Fas mediated pathway in early phase of infection indicating blocking of apoptosis which is a common strategy employed by viruses to evade host defense mechanisms that limits virus replication by killing infected cells. After wards upregulation of caspase 8 in mid to later stages of virus life cycle indicated Fas mediated pathway is responsible for apoptotic cell death. Caspase 8 and Caspase 3 which upregulated in response to IBDV infection in CEF cells indicating that the apoptosis induced by IBDV is caspase dependent.