Driesen Julia, Popov Alexey, Schultze Joachim L
Laboratory for Genomics and Immunoregulation, Program Unit Molecular Immune & Cell Biology, Institute for Life and Medical Sciences Bonn (LIMES), University of Bonn, Karlrobert-Kreitenstr. 13, D-53115 Bonn, Germany.
Immunobiology. 2008;213(9-10):849-58. doi: 10.1016/j.imbio.2008.07.026. Epub 2008 Sep 11.
CD25 (alpha-chain of IL-2 receptor) on dendritic cells (DC) has been previously regarded as an activation marker. DC that concomitantly express surface CD25 and co-stimulatory molecules were considered to be fully mature. While both murine and human DC can express CD25, they do not express the beta-chain of the IL-2 receptor, which is indispensable for the execution of IL-2 signaling. The biological function of CD25 during the DC maturation therefore still remains undefined. In this review we focus on recent findings, describing CD25 expression and secretion by human myeloid regulatory DC. These DC co-express CD25 and the immunoregulatory enzyme indoleamine 2,3-dioxygenase (IDO) and inhibit T-cell function. CD25, expressed and secreted by such DC may capture IL-2 and thereby suppress T-cell proliferation, by this means providing an accessory mechanism of DC-mediated immune suppression. We also discuss the implication of DC-derived CD25 for human disease in both cancer and chronic infection.
树突状细胞（DC）上的CD25（白细胞介素-2受体的α链）以前被视为一种激活标志物。同时表达表面CD25和共刺激分子的DC被认为是完全成熟的。虽然小鼠和人类DC都能表达CD25，但它们不表达白细胞介素-2受体的β链，而β链对于白细胞介素-2信号传导的执行是必不可少的。因此，CD25在DC成熟过程中的生物学功能仍不明确。在这篇综述中，我们重点关注最近的研究发现，描述人类髓系调节性DC对CD25的表达和分泌。这些DC共表达CD25和免疫调节酶吲哚胺2,3-双加氧酶（IDO）并抑制T细胞功能。此类DC表达和分泌的CD25可能捕获白细胞介素-2，从而抑制T细胞增殖，通过这种方式提供DC介导的免疫抑制的辅助机制。我们还讨论了DC来源的CD25在人类癌症和慢性感染疾病中的意义。
