S. epidermidis Rescues Allergic Contact Dermatitis in Sphingosine 1-Phosphate Receptor 2-Deficient Skin.

Recent studies have identified a subtype of the S1P-receptor family called sphingosine-1-phosphate receptor 2 (S1PR2), which plays a crucial role in maintaining the skin barrier. It has been observed that S1PR2 and Staphylococcus epidermidis ( S. epidermidis ) work together to regulate the skin barrier. However, the interaction between these two factors is still unclear. To investigate this, a study was conducted on healthy skin and allergic contact dermatitis (ACD) using 3,4-Dibutoxy-3-cyclobutene-1,2-dione (SADBE) on the ears of S1pr2 fl/f l and S1pr2 fl/f l K14-Cre mice and using 1 × 10 6 CFU of S. epidermidis to examine its effects on the skin. The results showed that in S. epidermidis -conditioned ACD, the ear thickness of S1pr2 fl/f l K14-Cre mice was lower than that of S1pr2 fl/f l mice, and mRNA expressions of Il-1β and Cxcl2 of S1pr2 fl/f l K14-Cre mice were lower than that of S1pr2 fl/f l mice in ACD with S. epidermidis . Furthermore, the gene expression of Claudin-1 and Occludin in S1pr2 fl/f l K14-Cre mice was higher than that of S1pr2 fl/f l mice in ACD with S. epidermidis . The study concludes that S. epidermidis colonization improves the skin barrier and prevents ACD even when S1P signaling malfunctions.