The objective of this study was to better understand the biological effects of Avene Thermal Water (ASW) on the immune system. Human dendritic cells (DC) were used for the study because they are antigen-presenting cells that play an important role in the induction and control of the immune system.

The effect of ASW was first evaluated on the differentiation and maturation of DC. Analysis of CD11c expression by flow cytometry was performed to evaluate DC differentiation. In addition, the expression of CD14, CD1a, CD83, CD86, and HLA-DR of DCs treated with LPS was measured. The results show that ASW reduces the expression of maturation and differentiation markers on the surface of LPS-treated DCs (or PGN or LTA in another experiment). On the other hand, the ability of DCs generated in ASW-treated media to activate native CD4+ T cells was also measured by analyzing CD4+ proliferation by flow cytometry. DCs generated in medium with ASW had a lower capacity to activate CD4+ T cells. 
Another experiment also showed that ASW decreased the amount of IL12 and IL23 produced by DCs treated with LPS and increased the amount of IL10. Finally, ASW was shown to significantly reduce the ability of DCs to induce the production of IFN-γ and IL-17 by TCD4+ cells.