Investigation of apoptosis in cultured cells infected with equine herpesvirus 1

Abstract

Many viruses alter different stages of apoptosis of infected cells as a strategy for successful infection. Few studies have addressed mechanisms of equine herpesvirus 1 (EHV-1) strain-induced cell death. We investigated the effect of an abortigenic strain (AR8 strain) on heterologous Madin–Darby bovine kidney cells and homologous equine dermis (ED) cells cell lines. We compared morphologic and biochemical features of early and late apoptosis at different postinfection times. We investigated translocation of phosphatidylserine to the cell surface, nuclear fragmentation and changes in the cytoskeleton using flow cytometry and annexin V/propidium iodide staining, DNA laddering, terminal deoxynucleotidyl transferase UTP nick-end labeling assay and immunofluorescence staining of cytokeratin 18 cleavage. AR8 EVH-1 strain interfered with apoptosis in both cell lines, particularly during the middle stage of the replication cycle; this was more evident in ED cells. Although this antiapoptotic effect has been reported for other alpha herpesviruses, our findings may help elucidate how EHV-1 improves its infectivity during its cycle.

Key words:

• apoptosis
• equine dermis cells
• equine herpes virus 1
• Madin–Darby bovine kidney cells

Acknowledgments

This study was supported by grants from Argentinean Agency for the Promotion of Science and Technology (PICT 2011-1123), CIC-PBA (1376/12 and 1395/13), the Department for Science and Technology of the National University of La Plata (11-V188 and 11-V221) and CONICET (PIP 11220120100189CO). We would like to thank the technicians Mr. Claudio A. Leguizamón and Mrs Adriana Conde for their supporting help, and Dr. Pablo Martino for the proofreading of the manuscript.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this paper.