Activation of host NF-kappa-B by virus

NF-kappa-B is a pleiotropic transcription factor which is present in almost all cell types and is involved in many biological processed such as inflammation, immunity, differentiation, cell growth, tumorigenesis and apoptosis. In unstimulated cells, NF-kappa-B dimers are sequestered in the cytoplasm via physical association with NF-kappa-B inhibitory proteins, called I-kappa-Bs. Upon activation, NF-kappa-B separates from I-kappa-B and migrates to the nucleus to activate gene transcription.

TRAFs RIP RIP TRAFs TRADD TRADD TNF TNFR CD4 LCK PI3K AKT MEKK1 PKC IKKgamma IKKalpha IKKbeta IKb IKb NIK core VP4 BORF1

Multiple families of viruses have evolved sophisticated strategies to positively regulate nuclear factor-kappaB (NF-kappaB) signaling. Different viruses including HIV, herpesviruses, and HCV block apoptosis and prolong survival of the host cell in order to gain time for replication and increase viral progeny production. In addition, several oncogenic viruses are able to install a program of constitutive expression of NF-kB-dependent anti-apoptotic which results in cell transformation and uncontrolled proliferation.