Biochimica et Biophysica Acta 2015-07-01

PKC theta and p38 MAPK activate the EBV lytic cycle through autophagy induction.

Roberta Gonnella, Marisa Granato, Antonella Farina, Roberta Santarelli, Alberto Faggioni, Mara Cirone

Index: Biochim. Biophys. Acta 1853 , 1586-95, (2015)

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Abstract

PKC activation by combining TPA with sodium butyrate (T/B) represents the most effective and widely used strategy to induce the Epstein-Barr virus (EBV) lytic cycle. The results obtained in this study show that novel PKCθ is involved in such process and that it acts through the activation of p38 MAPK and autophagy induction. Autophagy, a mechanism of cellular defense in stressful conditions, is manipulated by EBV to enhance viral replication. Besides promoting the EBV lytic cycle, the activation of p38 and autophagy resulted in a pro-survival effect, as indicated by p38 or ATG5 knocking down experiments. However, this pro-survival role was counteracted by a pro-death activity of PKCθ, due to the dephosphorylation of AKT. In conclusion, this study reports, for the first time, that T/B activates a PKCθ-p38 MAPK axis in EBV infected B cells, that promotes the viral lytic cycle and cell survival and dephosphorylates AKT, balancing cell life and cell death. Copyright © 2015 Elsevier B.V. All rights reserved.