Effect of spa spring water on cytokine expression in human keratinocyte HaCaT cells and on differentiation of CD4 ⁺ T cells

Background: Skin acts as the first line of defense against any foreign materials outside of our body. In inflammatory skin disease, the pathogenesis is due to an immune reaction in the keratinocytes, immune cells and soluble mediators. Balneotherapy is widely used for the treatment of inflammatory skin disease, but the mechanisms are only partly understood by immune regulation. Balneotherapy in dermatologic disease can affect the secretion of pro- inflammatory cytokines, IL-1 α and tumor necrosis factor from keratinocytes, and possibly affect the T cell differentiation. Objective: In this study, we evaluated the effect of spa spring water from Yong-gung oncheon on the cells, and investigated the skin immune reaction. Methods: We investigated the immunomodulatory or anti-inflammatory effect of thermal spring water on the expression of pro-inflammatory cytokines in the HaCaT cells under Toll-like receptor (TLR) stimulation, as well as the effect on the differentiation of CD4 ⁺ T cells under spring water. Results: The treatment of spa spring water from Yong-gung oncheon decreased the expression of proinflammatory cytokines under TLR stimulation to the HaCaT cells and antigen presenting cells. In addition, spa spring water attenuated the differentiation process of subsets of CD4 ⁺ T cells, i.e., Th1, Th2 and Th17 cells. All these immune parameters can be used to evaluate the efficacy of spa spring water in Korea, in terms of the immune modulatory effect. Conclusion: Spa spring water treatment suppressed the inflammatory cytokines production and also modulated the differentiation of CD4 ⁺ T cells into Th1, Th2, and Th17 cells, but not the Tregs cells. (Ann Dermatol 24(3) 324~336, 2012).