Table 4.
Effects of IFN-γ on KYN pathway enzyme activities in different cell types.
| Cell origin | IDO1 pmol/h/mg protein | KMO pmol/h/mg protein | Kynureninase pmol/h/mg protein | 3-HAO pmol/h/mg protein | ||||
|---|---|---|---|---|---|---|---|---|
|
|
|
|
|
|||||
| Control | IFN-γ | Control | IFN-γ | Control | IFN-γ | Control | IFN-γ | |
| Blood macrophages | 651 ± 134 | 7537 ± 864* | 3100 ± 376 | 2625 ± 200 | 949 ± 133 | 992 ± 104 | 1333 ± 376 | 1353 ± 376 |
| THP-1 (monocyte) | 260 ± 80 | (420 ± 2) × 103* | 363 ± 6 | 574 ± 27* | 11 ± 0.2 | 12 ± 0.2 | 1600 ± 60 | 1200 ± 20 |
| Human fetal brain (astrocytes and neurons) | <0.1 | (260.5 ± 2.2) × 103* | <0.1 | <0.1 | <0.05 | <0.05 | 37.5 ± 4.1 | 43.2 ± 11 |
| U363MG (astrocytoma) | 170 ± 20 | (369 ± 4.6) × 103* | <0.1 | <0.1 | 0.6 ± 0.1 | 0.5 ± 0.39 | <0.01 | <0.01 |
| SK-HEP1 (liver) | 170 ± 20 | (311 ± 5.2) × 103* | 85 ± 17 | 69 ± 14 | 3.0 ± 0.25 | 3.9 ± 0.25 | 1180 ± 120 | 1060 ± 88 |
| WIL-NS (B-lymphocyte) | 150 ± 20 | 580 ± 90 | <0.1 | <0.1 | <0.05 | <0.05 | 1.2 ± 0.1 | 1.1 ± 0.1 |
| MRC-9 (lung) | 120 ± 20 | (343 ± 4.6) × 103* | <0.1 | <0.1 | 1.6 ± 0.1 | 2.1 ± 0.39 | 300 ± 20 | 300 ± 20 |
Notes: Cells were incubated with or without (control) 100 unit/mL IFN-g. Values are expressed as means ± SEM from six incubation wells per time. For statistical comparisons, non-detected metabolites were set at the minimum detectable values.
*
Significant differences from respective control by one-way ANOVA and Mann-Whitney test.16