Circadian rhythm disruption exacerbates Th2‐like immune response in murine allergic airway inflammation.

Background: Chronic jet lag (CJL)‐induced circadian rhythm disruption (CRD) is positively correlated with an increased risk of allergic diseases. However, little is known about the mechanism involved in allergic rhinitis (AR). Methods: Aberrant light/dark cycles‐induced CRD mice were randomly divided into negative control (NC) group, AR group, CRD+NC group, and CRD+AR group (n = 8/group). After ovalbumin (OVA) challenge, nasal symptom scores were recorded. The expression of Occludin and ZO‐1 in both nasal mucosa and lung tissues was detected by reverse transcription–quantitative polymerase chain reaction (RT‐PCR) and immunohistochemical staining. The level of OVA–specific immunoglobulin E (sIgE) and T‐helper (Th)‐related cytokines in the plasma was measured by enzyme‐linked immunosorbent assay (ELISA), and the proportion of Th1, Th2, Th17, and regulatory T cell (Treg) in splenocytes was evaluated by flow cytometry. Results: The nasal symptom score in the CRD+AR group was significantly higher than those in the AR group with respect to eosinophil infiltration, mast cell degranulation, and goblet cell hyperplasia. The expression of ZO‐1 and Occludin in the nasal mucosa and lung tissues in the CRD+AR group were significantly lower than those in the AR group. Furthermore, Th2 and Th17 cell counts from splenocytes and OVA‐sIgE, interleukin 4 (IL‐4), IL‐6, IL‐13, and IL‐17A levels in plasma were significantly increased in the CRD+AR group than in the AR group, whereas Th1 and Treg cell count and interferon γ (IFN‐γ) level were significantly decreased in the CRD+AR group. Conclusion: CRD experimentally mimicked CJL in human activities, could exacerbate local and systemic allergic reactions in AR mice, partially through decreasing Occludin and ZO‐1 level in the respiratory mucosa and increasing Th2‐like immune response in splenocytes. [ABSTRACT FROM AUTHOR]