Related Experiment Videos
Avian encephalomyelitis virus induces apoptosis via major structural protein VP3
Jue Liu1, Ting Wei, Jimmy Kwang
1Animal Health Biotechnology Laboratory, Institute of Molecular Agrobiology, The National University of Singapore, 1 Research Link, 117604, Singapore.
Abstract:
Avian encephalomyelitis virus (AEV) strain L(2)Z was investigated for its apoptotic activity in specific-pathogen-free chick embryo brain tissue. DNA fragmentation analysis and electron microscopy observation demonstrated that AEV could induce apoptosis in chick embryo brain tissues characterized by chromatin condensation, plasma membrane blebbing, cell shrinkage, and nucleosomal DNA fragmentation after 4 days postinfection. AEV structural protein genes VP1, VP2, and VP3 were transfected into Cos-7 and chick embryo brain (CEB) cells, respectively. The results showed that only VP3 protein was an apoptotic inducer, as demonstrated by DNA fragmentation analysis and TUNEL assay at 24 and 48 h posttransfection. Furthermore, expression of VP3 protein resulted in the activation of caspase-3-like proteases in both cells, which could be inhibited by a caspase-3-like protease-specific inhibitor Ac-DEVD-CHO peptide, suggesting that AEV VP3 protein induces apoptosis through a caspase-3-like protease pathway. In addition, VP3 protein localized to mitochondria in the Cos-7 and CEB cells at 24 h posttransfection observed by confocal microscopy, indicating that mitochondria may play an important role in VP3-induced apoptosis. Taken together, our results show that AEV could induce apoptosis in chick embryo brain tissue, structural protein VP3 could serve as an apoptotic inducer resulting in apoptosis in cell culture through a caspase-3-like protease pathway, which may be related to its localization to mitochondria.
Insights
Avian encephalomyelitis virus (AEV) induces apoptosis in chick brains. The AEV structural protein VP3 triggers this cell death pathway via caspase-3-like proteases and mitochondrial localization.
Area of Science:
- Virology
- Cell Biology
- Molecular Biology
Background:
- Avian encephalomyelitis virus (AEV) is a significant pathogen affecting poultry.
- Understanding the mechanisms of viral-induced cell death is crucial for developing control strategies.
Purpose of the Study:
- To investigate the apoptotic activity of AEV strain L(2)Z in chick embryo brain tissue.
- To identify the specific AEV structural protein responsible for inducing apoptosis.
- To elucidate the molecular pathway involved in AEV-induced apoptosis.
Main Methods:
- DNA fragmentation analysis and electron microscopy were used to assess apoptosis in infected chick embryo brain tissue.
- AEV structural protein genes (VP1, VP2, VP3) were transfected into Cos-7 and chick embryo brain (CEB) cells.
- TUNEL assay, caspase-3-like protease activity assays, and confocal microscopy were employed to study VP3-induced apoptosis.
Main Results:
- AEV infection induced characteristic apoptotic changes in chick embryo brain tissue.
- Only the AEV VP3 protein demonstrated apoptotic activity in cell culture.
- VP3 expression activated caspase-3-like proteases, indicating a caspase-dependent pathway.
- VP3 protein localized to mitochondria, suggesting their involvement in the apoptotic process.
Conclusions:
- AEV induces apoptosis in chick embryo brain tissue.
- AEV structural protein VP3 is an apoptotic inducer acting through a caspase-3-like protease pathway.
- Mitochondrial localization of VP3 may be critical for its role in inducing apoptosis.