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 S1pr(2fl/fl) and S1pr(2fl/fl) K14-Cre mice and using 1 x 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 S1pr(2fl/fl) K14-Cre mice was lower than that of S1pr(2fl/fl) mice, and mRNA expressions of Il-1 beta and Cxcl2 of S1pr(2fl/fl) K14-Cre mice were lower than that of S1pr(2fl/fl) mice in ACD with S. epidermidis. Furthermore, the gene expression of Claudin-1 and Occludin in S1pr(2fl/fl) K14-Cre mice was higher than that of S1pr(2fl/fl) 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.