The restraint stress drives a shift in Th1/Th2 balance toward Th2-dominant immunity in mice.

When mice were physically restrained in 50-ml tubes for 24 h, a marked decrease of NK activity was demonstrated in parallel with the elevation of serum corticosterone levels. The release of mice from restraint stress resulted in the recovery of NK activity, with a decrease of serum corticosterone levels within 48 h. Using this stress model, we also investigated the influence of restraint stress on mouse Th1/Th2 balance. Consistent with the decrease of NK activity, IFN-gamma production of mouse spleen cells greatly reduced after suffering from restraint stress. In contrast, the IL-4 producing ability of spleen cells was not so much affected by restraint stress. These results initially indicated that stress may induce the skewing of the Th1/Th2 balance toward Th2-dominant immunity, which stimulates the occurrence of infectious diseases and allergic disorders.