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Updated: Jun 20, 2026

Identifying Caspases and their Motifs that Cleave Proteins During Influenza A Virus Infection
Published on: July 21, 2022
Bid cleavage, cytochrome c release and caspase activation in canine coronavirus-induced apoptosis
Luisa De Martino1, Gabriella Marfé, Mariangela Longo
1Department of Pathology and Animal Health, Infectious Diseases, Faculty of Veterinary Medicine, University of Naples Federico II, Via F. Delpino 1, 80137 Naples, Italy.
Abstract:
A previous study demonstrated that infection of a canine fibrosarcoma cell line (A-72 cells) by canine coronavirus (CCoV) resulted in apoptosis (Ruggieri et al., 2007). In this study, we investigated the cell death processes during infection and the underlying mechanisms. We found that CCoV-II triggers apoptosis in A-72 cells by activating initiator (caspase-8 and -9) and executioner (caspase-3 and -6) caspases. The proteolytic cleavage of poly(ADP-ribose) polymerases (PARPs) confirmed the activation of executioner caspases. Furthermore, CCoV-II infection resulted in truncated bid (tbid) translocation from the cytosolic to the mitochondrial fraction, the cytochrome c release from mitochondria, and alterations in the pro- and anti-apoptotic proteins of bcl-2 family. Our data indicated that, in this experimental model, both intrinsic and extrinsic pathways are involved. In addition, we demonstrated that the inhibition of apoptosis by caspase inhibitors did not affect CCoV replication, suggesting that apoptosis does not play a role in facilitating viral release.
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Overview of Cell Death
Cell death was observed in the early 19th century, but there was no experimental evidence to prove it. In 1842, Carl Vogt first discovered cell death in a metamorphic toad; however, it was not termed ‘cell death.’ Scientists discovered different cell death pathways only in the 20th century...

