Polyamines (i.e., putrescine, spermidine, and spermine) are bioactive polycations capable of binding nucleic acids and proteins and modulating signaling pathways. Polyamine functions have been studied most extensively in tumors, where they can promote cell transformation and proliferation. Recently, spermidine was found to exert protective effects in an experimental model of multiple sclerosis (MS) and to confer immunoregulatory properties on dendritic cells (DCs), via the indoleamine 2,3-dioxygenase 1 (IDO1) enzyme. IDO1 converts l-tryptophan into metabolites, collectively known as kynurenines, endowed with several immunoregulatory effects via activation of the arylhydrocarbon receptor (AhR). Because AhR activation increases polyamine production, the emerging scenario has identified polyamines and kynurenines as actors of an immunoregulatory circuitry with potential implications for immunotherapy in autoimmune diseases and cancer.

多胺（即腐胺，亚精胺和亚精胺）是能够结合核酸和蛋白质并调节信号传导途径的生物活性聚阳离子。多胺功能已经在肿瘤中得到了最广泛的研究，它们可以促进细胞转化和增殖。最近，发现亚精胺通过吲哚胺2,3-二加氧酶1（IDO1）酶在多发性硬化症（MS）的实验模型中发挥保护作用，并赋予树突状细胞（DC）免疫调节特性。IDO1转换l色氨酸转化为代谢产物（统称为犬尿氨酸），通过激活芳基烃受体（AhR）具有多种免疫调节作用。由于AhR激活增加了多胺的产生，因此新出现的情况已确定多胺和犬尿氨酸是免疫调节电路的参与者，对自身免疫性疾病和癌症的免疫治疗具有潜在的影响。