Figure 2.

Possible temporal relationships between epithelial barrier function and allergic immune response. Epithelial barrier function and immune response associated with allergic disease (allergic immune response) are under control of the circadian clock. We speculate that epithelial barrier function and allergic immune response might temporally complement to each other. Briefly, clock system may maximize allergic immune response at the time-of-day when epithelial barrier function is weakest. This may be because the risk of attack by helminth and biting arthropods is highest at that time.