Medical Oncology Immunotherapy Group, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire 03756, USA.
Cytotherapy. 2009;11(8):1084-9. doi: 10.3109/14653240903271230.
Polarized mature dendritic cells (DC) can activate cytolytic T-lymphocyte (CTL) responses and may be a more effective clinical strategy in DC-based cancer vaccines. A subset of mature DC can down-regulate the T-cell immune response through expression of indoleamine-2,3-dioxygenase (IDO). We determined whether polarizing DC ex vivo increased IDO expression and activity.
Peripheral blood monocytes from healthy volunteers were cultured ex vivo in polarizing and non-polarizing culture conditions. DC IDO expression was detected by Western blot. IDO enzyme activity was determined by high-performance liquid chromatography (HPLC) measurement of kynurenine (K) and tryptophan (T) concentrations in culture supernatants.
IDO protein was markedly increased in DC after polarization (median 1222.4%, range 331.5-2113.3%) versus non-polarized DC (median 28.3%, range 3.7-119.8%; P=0.04). The median K/T ratio was significantly higher in polarized DC versus non-polarized DC (6.34, range 6.02-6.65, versus 0.047, range 0.004-0.541; P=0.04). IDO protein expression correlated with enzyme activity (r=0.80, P=0.002).
DC polarizing culture conditions increased expression of IDO protein and IDO enzyme activity. DC culture and maturation methodologies may impact the effectiveness of adoptive DC therapy.
极化的成熟树突状细胞（DC）可以激活细胞毒性 T 淋巴细胞（CTL）反应，并且可能是基于 DC 的癌症疫苗的更有效的临床策略。成熟 DC 的一个亚群可以通过表达吲哚胺 2,3-双加氧酶（IDO）来下调 T 细胞免疫反应。我们确定了体外极化 DC 是否会增加 IDO 的表达和活性。
从健康志愿者的外周血单核细胞在体外培养于极化和非极化培养条件下。通过 Western blot 检测 DC IDO 的表达。通过高效液相色谱法（HPLC）测量培养上清液中犬尿氨酸（K）和色氨酸（T）的浓度来确定 IDO 酶活性。
与非极化 DC 相比（中位数 28.3%，范围 3.7-119.8%；P=0.04），极化后 DC 中的 IDO 蛋白明显增加（中位数 1222.4%，范围 331.5-2113.3%）。与非极化 DC 相比，极化 DC 的 K/T 比值显著更高（中位数 6.34，范围 6.02-6.65，vs 0.047，范围 0.004-0.541；P=0.04）。IDO 蛋白表达与酶活性相关（r=0.80，P=0.002）。
DC 极化培养条件增加了 IDO 蛋白和 IDO 酶活性的表达。DC 培养和成熟方法可能会影响过继性 DC 治疗的效果。
