Figure 5.

Assessment of Tryptophan catabolism at both peripheral and tumor levels upon pharmacological inhibition of IDO1 and PDL1 blockade. MCA205 tumor-bearing mice were treated with either GDC-0919, anti-PDL1, or combination of both. (A) Mice were bled at different time-points following tumor inoculation, and Kynurenine to Tryptophan ratio was analyzed by mean of ELISA. (B) Thirteen days post tumor inoculation, animals from all the experimental groups were processed for intratumoral microdialysis and several metabolites of the KP—Kynurenine, Tryptophan, Kynurenine to Tryptophan ratio, Kynurenic Acid, and 3-OH Anthranilic acid—were quantified in the collected dialysates by LC/MS. For statistical analysis, student t-test was used. *p < 0.05, **p < 0.01, ***p < 0.001, NS, not significant. Means ± SEM are represented. In A, experimental groups are compared to Vehicle-treated animals.