Effects of irradiation on cytokine production in a mouse model of Behçet's disease.

Abstract

OBJECTIVE: Low-dose whole-body irradiation is known to have anti-inflammatory effects. The objectives of this study were to verify that cytokine augmentation is induced by irradiation in vivo, and to assess the effectiveness of radiation in treating Beh&#xe7;et's disease (BD). METHODS: Whole-body and half-body irradiation with single doses of 10cGy, 2Gy and 10Gy were delivered to normal mice, and cytokine and chemokine levels were analyzed in PBMC and sera. BD-like mice were treated with low-dose, half-body 10cGy irradiation. RESULTS: In normal mice, PBMC cytokine mRNA levels peaked four days after irradiation. Of the cytokines and chemokines examined, the levels of IL-4, IL-6, IL-12p40, TNF-alpha, TGF-b, MIP-1alpha and IL-18 were all influenced by radiation treatment. Of these, IL-4, an ameliorating factor for BD, was the most elevated following low-dose irradiation (10cGy group). FACS analysis showed intracellular IL-4-staining of 7.24+/-0.92% of PBMC from irradiated mice compared to 1.3+/-0.1% from non-irradiated, normal mice (p<0.005). Serum IL-4 levels were also significantly increased (6.08+/-1.7 pg/ml) relative to control (1.83+/-0.8; p<0.005). CONCLUSION: Augmentation of cytokine production may contribute to the anti-inflammatory effects of low dose irradiation and amelioration of BD symptoms in this mouse model.