Fig. 5

Tumor-infiltrating lymphocytes (TIL) and KYN and TRP level assessments syngeneic and humanized mouse models. Dead cells were excluded with fixable viability dye (FVD). Lymphocytes gated based on SSC-A versus FSC-A and CD45 + /FVD negative were selected (see gating strategy in Supplemental Figure S1B). A, C Both IDOi and AT-0174 (AT) suppressed T-reg and increased NKG2D frequencies on NKs as well as CD8 + T cells in CR tumors. However, higher NKG2D frequencies on NK and CD8 + T but lower Treg populations were found in the AT-0174 treatment group vs. IDOi. B, D Higher basal KYN levels of KYN but lower levels of TRP were detected in the serum of CR tumor-bearing mice. Importantly, AT-0174 significantly suppressed KYN secretion and increased extracellular TRP. Data were analyzed using one-way ANOVA followed by Tukey’s multiple comparisons for KYN and TRP concentrations and Dunnett’s multiple comparisons for the immune profile with *P < 0.05, **P < 0.005, ***P < 0.0005, ****P < 0.0001