Toll-like receptor 2 mediates a cutaneous reaction induced by repetitive ultraviolet b irradiation in c57/bl6 mice in vivo = Toll-like receptor 2 mediates a cutaneous reaction induced by repetitive ultraviolet b irradiation in c57/bl6 mice in vivo

다국어 초록 (Multilingual Abstract)

Background: Toll like receptors (TLR) are a family of pattern recognition receptors that play an essential role in the induction of the immune response. Objectives: Previous studies suggested that single ultraviolet (UV) exposure may initiate a TLR-mediated sterile inflammation in vitro. This study was conducted to verify whether TLR2 mediates sterile inflammation, which is induced by repetitive to UVB exposure in vivo. Methods: Inflammatory responses to repetitive UVB irradiation were compared between wild-type (WT) and TLR2 knock-out (KO) mice. Results: After 6 weeks of repetitive UVB irradiation, inflammatory response of the TLR2 KO group was less severe than that of the TLR2 WT group. Compared to the group of TLR2 WT mice, the group of TLR2 KO mice displayed less prominent erythema and scaling; and histopathologically fewer inflammatory cells and significantly thinner skin. UVB-induced expression of the heat shock protein 70, an endogenous ligand of TLR2, was lower in the TLR2 KO group. Quantitative RT-PCR was used to measure the gene expression levels of interleukin (IL)-1β, IL-6, and matrix metalloproteinase (MMP)-13, all of which were lower in the TLR2 KO group, compared to the WT group. This finding was further corroborated with ELISA and western blot, each of which showed lower protein expression level of IL-1β, and MMP-13, respectively. Conclusion: This study demonstrated that TLR2 is involved in cutaneous inflammatory reaction to repetitive UV irradiation in C57/B16 mice.