变应性鼻炎中的色氨酸代谢及机制

Tryptophan metabolism and its mechanism in allergic rhinitis

变应性鼻炎是免疫疾病中常见的上呼吸道疾病,也是常见的慢性疾病之一.一般症状为鼻塞、流清涕、打喷嚏.其发病是由许多因素造成的,目前有文献报道色氨酸代谢与变应性鼻炎相关.色氨酸代谢途径为细菌代谢(外源性代谢)与内源性代谢.内源性代谢主要限速酶为吲哚胺2,3-双加氧酶,通过犬尿氨酸途径代谢物作用芳基烃受体,诱导调节性T细胞增殖,促进白介素-10分泌、抑制免疫、降低过敏反应.色氨酸细菌性代谢能产生大量的代谢产物,其中吲哚是一种主要的细菌色氨酸代谢物.吲哚能增加FoxP3的表达,诱导调节性T细胞的增殖.同时也能通过调节microRNA诱导促炎Th17细胞向抗炎调节性T细胞转变,从而抑制迟发性超敏反应.

Allergic rhinitis is a common upper respiratory tract disease in immune diseases and one of the common chronic diseases. General symptoms for nasal congestion, runny, sneezing. The disease is caused by many factors. It has been reported that tryptophan metabolism is associated with allergic rhinitis. Tryptophan metabolism pathway is bacterial metabolism (exogenous metabolism) and endogenous metabolism. The main rate-limiting enzyme of endogenous metabolism is indoleamine 2, 3-dioxygenase (IDO), acts on the (AHR), of aryl hydrocarbon receptor through kynurenine pathway metabolite to induce the proliferation of tregs, promote the secretion of IL-10, inhibit the immunity and decrease the allergic reaction. Bacterial metabolism of tryptophan produces a large number of metabolites, of which indole is a major tryptophan metabolite in bacteria. Indole could increase the expression of foxp3 and induce the proliferation of tregs. It can also inhibit delayed hypersensitivity by regulating microrna-induced transformation from pro-inflammatory Th17 cells to anti-inflammatory tregs.