CARMA3 Regulates RIG-I/MAVS-Mediated IKK/NF-kB Activation and TBK1/IRF3 Activation in an Independent Manner Interestingly, we found that VSV infection-induced NF-kB activation could be detected as early as the first hour post-infection, whereas IRF3 phosphorylation was not detectable until 4 hr post-infection ( Figures 2C and 3C ).