Figure 8: The combining therapy of IFN-γ and 1-MT/DMF targets tumour independent of the adaptive immune system.

(a) The NOD-SCID mice (n=8) with B16 melanoma (7 × 7 mm) were treated with IFN-γ/1-MT for 1 week. The tumour growth was measured. (b) IDO1-stably silencing or scramble control B16 cells (1 × 10⁵) were s.c. injected to C57BL/6 mice (n=10 per group). The tumour growth was measured (left) and long-term survival was analysed (right). (c) IDO1-knockdown or scramble control B16 cells were injected to C57BL/6 mice (n=8 per group). Twelve hours before tumour cell injection, mice were treated with anti-IFN-γ antibody (250 μg) once every 2 days. Tumour growth was measured. (d) C57BL/6 mice (n=10 per group) were s.c. injected with 1 × 10⁵ B16 cells. Three days later, mice were treated with IFN-γ (intratumoral injection of 20 μg per day, once every 2 days), 1-MT (5 mg ml⁻¹ in drinking water, 3–4 ml per mouse per day) or IFN-γ/1-MT for 10 days. The tumour growth was measured (left) and long-term survival was analysed (right). (e) Three days after injection of 1 × 10⁵ B16 cells, C57BL/6 mice were treated with IFN-γ, DMF (intragastric injection of 10 mg kg⁻¹, once per 2 days) or IFN-γ/DMF for 10 days (n=10 per group). The tumour growth was measured (left) and long-term survival was analysed (right). The data represent mean±s.e.m., *P<0.05, **P<0.01, ***P<0.001 versus PBS group; ^#P<0.05, ^##P<0.01 versus Scr or IFN-γ group (Student’s t-test or Kaplan–Meier analysis).