NF-κB activation by equine arteritis virus is MyD88 dependent and promotes viral replication
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NF-κB, a family of transcription factors involved in different cell functions and immune responses is targeted by viruses. The mechanism of NF-κB signalling and its role in replication of EAV have not been investigated. We demonstrate that EAV infection in BHK-21 cells activates NF-κB, and this activation was found to be mediated through the MyD88 pathway. Infection of IKKβ−/− murine embryo fibroblasts (MEFs), which are deficient in NF-κB signalling, resulted in lower virus titre, less cytopathic effect, and reduced expression of viral proteins. These findings implicate the MyD88 pathway in EAV-induced NF-κB activation and suggest that NF-κB activation is essential for efficient replication of EAV.
This work was supported by grant 221-2006-2343 from The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Formas). MEFs were kindly provided by Dr. Amer Beg (Moffitt Cancer Center, USA) and Dr. Siddharth Balachandran (Fox Chase Cancer Center, USA) through Dr. Muhammad Munir. The antibody against EAV nsp3 proteins was kindly provided by Prof. Eric Snijder (LUMC, The Netherlands). The antibody against EAV N protein was kindly provided by Dr. Amy Glaser (Cornell University, USA). We thank Dr. Muhammad Munir for critically reading the manuscript and providing reagents.
Conflict of interest
The authors declare that they have no competing interests.
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