The aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor, can regulate the immune balance of Th17/22 and Treg cells, which plays an important role in the development and maintenance of the skin barrier. We herein report the discovery of triazolopyridine derivatives as a new class of AhR agonists. Structure-activity relationship analyses led to the identification of the most active compound, 6-bromo-2-(4-bromophenyl)-[1,2,4]triazolo[1,5-a]pyridine (12a), with an EC₅₀ (50% effective concentration) value of 0.03 nM. Compound 12a could induce rapid nuclear enrichment of AhR, trigger the transcription of downstream genes and promote skin barrier repair. Topical or oral administration of 12a could significantly alleviate imiquimod (IMQ)-induced psoriasis-like skin lesion. Considering the excellent in vivo anti-psoriasis activity as well as good pharmacokinetic properties, 12a could be a promising lead compound for drug discovery against psoriasis, and deserving further investigation.

芳烃受体（AhR）是一种配体依赖性转录因子，可调节Th17/22和Treg细胞的免疫平衡，在皮肤屏障的发育和维持中发挥重要作用。我们在此报告了作为一类新的 AhR 激动剂的三唑并吡啶衍生物的发现。结构-活性关系分析导致鉴定出最活跃的化合物 6-bromo-2-(4-bromophenyl)-[1,2,4]triazolo[1,5- a ]pyridine ( 12a )，具有 EC ₅₀（50%有效浓度）值为0.03 nM。化合物12a可以诱导AhR的快速核富集，触发下游基因的转录，促进皮肤屏障修复。12a的局部或口服给药可显着减轻咪喹莫特（IMQ）诱导的银屑病样皮肤病变。考虑到优异的体内抗银屑病活性和良好的药代动力学特性，12a可能是一种很有前途的先导化合物，用于发现抗银屑病药物，值得进一步研究。