Immunological and Nonimmunological Effects of Indoleamine 2,3-Dioxygenase on Breast Tumor Growth and Spontaneous Metastasis Formation

Figure 1

Generation of two pairs of Ido1+ and Ido1− clones from murine breast cancer cells. (a) RT-PCR (top picture) real-time PCR (bottom picture) analysis of Ido1 expression in 4T1 cells, cells transfected with vector (4T1/V), and cells transfected with shRNA for Ido1 (4T1/Ido1−). Fold change was compared with 4T1. (b) Real-time PCR analysis of the effect of INF-γ treatment (INF-γ, 25 ng/mL, 24 hours) on Ido1 expression in 4T1, 4T1/V, and 4T1/Ido1− cells. (c) Ido1 expression in NT-5 cells transfected with vector (NT-5/V) and cells transfected with Ido1 cDNA (NT-5/Ido1+) detected by RT-PCR (top picture) and by Real-time PCR (bottom picture). (d) Enzymatic IDO activity in 4T1, 4T1/Ido1−, NT-5, and NT-5/Ido1+ cells. IDO activity is defined as the amount of enzyme required to produce 1 nmol of kynurenine per hr per 1 mg of protein. All values are the means of four measurements.