['Nitric oxide (NO) has previously been shown to inhibit human rhinovirus (HRV) replication in airway epithelial cells and to inhibit rhinovirus-induced epithelial cytokine and chemokine production independently of its effects on viral replication by modulating nuclear translocation and binding of transcription factors.', 'To define the molecular mechanisms by which NO inhibits HRV-16-induced epithelial production of CXCL10 by affecting nuclear translocation and binding of nuclear factor-kappaB (NF-kappaB) and IFN regulatory factor 1 (IRF-1).', 'Cultured human airway epithelial cells were infected with HRV-16 in the absence or presence of a NO donor, or were preincubated with 2 highly selective inhibitors of inhibitor of kappaB kinase (IKK)beta and then infected with HRV-16. Effects on the NF-kappaB and IRF-1 pathways were examined by using electrophoretic mobility shift assays, Western blotting, and real-time RT-PCR.', 'Nitric oxide directly inhibited the binding of both recombinant NF-kappaB p50 protein and recombinant IRF-1 to their recognition sequences from the CXCL10 promoter. NO also inhibited phosphorylation of the NF-kappaB inhibitor, IkappaBalpha, in HRV-16-infected cells. In addition, both NO and inhibitors of IKKbeta inhibited viral induction of IRF-1 mRNA and protein.'] Does nitric oxide inhibit IFN regulatory factor 1 and nuclear factor-kappaB pathways in rhinovirus-infected epithelial cells?