FIGURE 6.

T cells transferred with the M8 live-passage inoculum expand in lymphopenic hosts and reveal a profile of direct cIAP1/2 antagonism. (A) Experimental diagram showing use of depleting Abs in the tumor inoculum. (B) C57BL/6 or TCRα^−/− mice were implanted orthotopically with M8 live-passage organoids and treated with vehicle or LCL-161 (75 mg/kg) by oral gavage every 3 d starting on day 4. Tumors were harvested on day 21. Tumor weights were normalized to the average of the vehicle control mice, and results shown are pooled from two experiments. In the left panels, the inoculum was untreated; in the right panels, the inoculum was treated with 10 μg/ml anti-CD4 and anti-CD8 depleting Abs prior to inoculation. Error bars are SEM. ANOVA with multiple comparisons was used. n = 4–10 mice per group. (C and D) TCRα^−/− mice were implanted orthotopically with M8 live-passage organoids and treated with vehicle or LCL-161 (75 mg/kg) by oral gavage every 3 d starting on day 4. Tumors and spleens were harvested on day 12 after three doses of LCL-161 and single-cell suspensions were prepared. CD4 and CD8 T cells were isolated by FACS and subjected to limited bulk transcriptional profiling. n = 3 per group. (C) Differential gene expression analysis comparing CD8 T cells from tumors treated with vehicle or LCL-161. (D) Gene set enrichment analysis for hallmark TNFA signaling via NF-κB and hallmark G2M checkpoint gene sets was performed on tumor-infiltrating CD4 and CD8 T cell datasets.