Skip to main content
Figure 5 | BMC Cancer

Figure 5

From: Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes

Figure 5

Cytolytic activity of peripheral blood lymphocytes (PBLs) was impaired by incubation with CNE2-CM from indoleamine 2,3-dioxygenase-positive CNE2 cells. (A) Activated PBLs were cultured with CNE2-CM from CNE2 cells treated with or without 50 U/ml IFNγ for 24 h and cytolytic activity against CNE2 cells was evaluated using a standard lactate dehydrogenase (LDH) release assay, as described in Materials and Methods. The effector:target (E/T) ratios are indicated. (B) Activated PBLs were cultured with CNE2-CM from CNE2 cells treated with or without 50 U/ml IFNγ and/or 100 μM 1 MT for 24 h, and cytolytic activity was evaluated using the LDH release assay. The E/T ratio was 10:1. (C) CNE2 cells were treated with or without 50 U/ml IFNγ and/or 100 μM 1 MT for 24 h. The CNE2 cell supernatants were analyzed for kynurenine production by high performance liquid chromatography, as described in Materials and Methods. (D) Activated PBLs were incubated with CNE2-CM from IFNγ-treated or untreated CNE2 cells containing 100 U/ml IL-2 for 96 h, and restored groups were transferred to IL-2-supplemented fresh medium for 24 h, the cytolytic activity of each group was analyzed by LDH release assay. The E/T ratio was 10:1. Effector cells, activated PBLs; target cells, CNE2 cells; CNE2-CM, conditioned medium from CNE2 cells; Kyn, kynurenine.

Back to article page