Immunohistochemical demonstration of caspase inhibition in skin and visceral organ lesions in naturally occurring sheep poxvirus infection

The objective of this immunohistochemical study was to examine the expression of caspase-3,-5,-7, and -9 in sheep pox lesions in 15 naturally infected crossbred merino lambs. Sheep pox was diagnosed based on typical gross and histopathological lesions in the skin and visceral organs that were evaluated pathologically and immunohistochemically. Macroscopically, lesions were observed in the skin and visceral organs. Characteristic sheep pox inclusion bodies and cellules claveleuses (sheep pox cells) were present in all cases. After histopathological examinations, tissue sections were immunostained for caspase-3,-5,-7, and -9. While strong positive reactions were observed in normal tissue, only weak expression was noted in poxvirus lesions, demonstrating marked caspase inhibition in naturally infected lambs. This finding suggests a role for caspases in sheep poxvirus infection and its pathogenesis. © 2016, Israel Veterinary Medical Association. All rights reserved