Defective NF-kappaB activation in virus-infected neuronal cells is restored by genetic complementation

The interferon-beta (IFNbeta) gene is not inducible in neuronal cells in response to measles virus (MV) due to lack of nuclear factor kappa B (NF-kappaB) activation. NF-kappaB is normally sequestered in the cytoplasm by an inhibitor (IkappaBalpha). Previously, the authors demonstrated that the failure to activate neuronal NF-kappaB by MV was due to the inability to phosphorylate and degrade its inhibitor, IkappaBalpha. Here the authors demonstrate that transient transfection of a brain cDNA library into neuronal cells restores the ability of MV to activate NF-kappaB. In addition, tumor necrosis factor-alpha (TNFalpha), but not interleukin-1 (IL-1) or lipopolysaccharide (LPS), stimulation resulted in IkappaBalpha phosphorylation and degradation in two neuronal cell lines. These results indicate that failure of MV to activate neuronal NF-kappaB is due to a signaling defect and that MV utilizes an NF-kappaB signaling pathway distinct from that of TNFalpha, but may overlap with that for IL-1 and LPS.