Related Experiment Video
Updated: Jun 18, 2026
Development and Functional Characterization of Murine Tolerogenic Dendritic Cells
Published on: May 18, 2018
Indoleamine-2,3-dioxygenase enzyme expression and activity in polarized dendritic cells
Benita Wolf1, David Posnick, Jan L Fisher
1Medical Oncology Immunotherapy Group, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire 03756, USA.
Background Aims:
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.
Methods:
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.
Results:
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).
Conclusions:
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.
