Interleukin 4 directly activates olfactory neurons and induces loss of smell in mice

Anosmia is common in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Dupilumab, a human IL-4Rα monoclonal antibody that blocks both IL-4 and IL-13 signaling, provides rapid and sustained improvements in sense of smell in patients with CRSwNP via mechanisms not clearly understood. Therefore, we investigated the effects of IL-4 and IL-13 on the mouse olfactory system in vitro and in vivo.