Expression of Th2 cytokines decreases the development of and improves Behcet's disease-like symptoms induced by herpes simplex virus in mice

In the etiology of Behcet's disease (BD), viral infection has long been pos tulated as a contributing factor, and viral involvement has been demonstrat ed. However, viral infection alone is not sufficient to explain the pathoge nesis of BD, and some evidence suggests that immunologic abnormalities are also important. To study the possible role of immune regulation in the deve lopment of BD-like symptoms induced by herpes simplex virus inoculation in ICR mice, macrophages were deleted by use of liposome-encapsulated clodrona te (lip-Cl2MDP). Treatment with lip-Cl2MDP suppressed the development of BD -like symptoms, and this suppression was correlated with the induction of i nterleukin-4 expression in mouse spleens. When the Th2 adjuvant ovalbumin ( OVA)-alum was injected into mice with BD-like symptoms, their cutaneous sym ptoms improved. Adoptive transfer with splenocytes from OVA-alum-injected m ice also resulted in improvement. These findings suggest that up-regulated Th2 cytokine expression can attenuate the development of and improve some B D-like symptoms.