Abstract
The aryl hydrocarbon receptor (AHR) is known as a sensor for dioxins that mediates their toxicity, and also has important biophysiological roles such as circadian rhythms, cell differentiation and immune responses. 6-formylindolo(3,2-b)carbazole (FICZ), which is derived through the metabolism of L-tryptophan by ultraviolet B irradiation, is one of putative physiological ligands for AHR ( Smirnova et al., 2016 ). It has recently been shown that endogenously-activated AHR signaling modulates innate immune response during viral infection ( Yamada et al., 2016 ). This section describes how to treat mice with FICZ and to infect them with virus.