title: Bovine herpesvirus type 4 infection modulates autophagy in a permissive cell line.
abstract: Bovine herpesvirus type 4 (BoHV-4), like other herpesviruses, induces a series of alterations in the host cell that modify the intracellular environment in favor of viral replication, survival and spread. This research examined the impact of BoHV-4 infection on autophagy in BoHV-4 infected Madin Darby bovine kidney (MDBK) cells. Protein extracts of BoHV-4 infected and control MDBK cells were subjected to Western blot. The concentrations of the autophagy and apoptosis-related proteins Beclin 1, p21, PI3 kinase, Akt1/2, mTOR, phospho mTOR, p62 and the light chain three (LC3) were normalized to the actin level and expressed as the densitometric ratio. Western blot analysis of virus-infected cells revealed that autophagic degradation pathway was induced in the late phase of BoHV-4 infection. After 48 h post-infection the protein LC3II, which is essential for autophagy was found to be markedly increased, while infection of MDBK cells with BoHV-4 resulted in a depletion of p62 levels. Becline 1, PI3 kinase, Akt1/2 and p21 expression increased between 24 and 48 h post-infection. Surprisingly, mTOR and its phosphorylated form, which are negative regulators of autophagy, also increased after 24 h post-infection. In conclusion, our findings suggest that BoHV-4 has developed mechanisms for modulation of autophagy that are probably part of a strategy designed to enhance viral replication and to evade the immune system. Additional studies on the relationship between autophagy and BoHV-4 replication and survival, in both lytic and latent replication phases, are needed to understand the role of autophagy in BoHV-4 pathogenesis.
authors.affiliation: Department of Pathology and Animal Health, School of Veterinary Medicine, University of Naples, Naples, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Montagnaro
authors.forename: Roberto
authors.initials: R
authors.lastname: Ciarcia
authors.forename: Francesco
authors.initials: F
authors.lastname: Pagnini
authors.forename: Luisa
authors.initials: L
authors.lastname: De Martino
authors.forename: Maria Valeria
authors.initials: MV
authors.lastname: Puzio
authors.forename: Giovanna Elvira
authors.initials: GE
authors.lastname: Granato
authors.forename: Franca
authors.initials: F
authors.lastname: Avino
authors.forename: Ugo
authors.initials: U
authors.lastname: Pagnini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Iovane
authors.forename: Antonio
authors.initials: A
authors.lastname: Giordano
mesh_terms: D000818:Animals; D001343:Autophagy / Q000502:physiology*; D015153:Blotting, Western; D002417:Cattle; D002460:Cell Line; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004261:DNA Replication / Q000235:genetics / Q000502:physiology; D026021:Herpesvirus 4, Bovine / Q000472:pathogenicity*
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21