Single-cell RNA sequencing of circulating OR tumor infiltrating mock-electroporated and BTLA-knockout 41BBzeta CART19 cells

Single-cell gene expression of 4-1BBzeta CART19 cells in both the peripheral blood (model 1) and tumor-infiltrating (model 2) of OCI-Ly18 DLBCL-bearing mice. Cells were captured and processed using 10X 5' v2 Chemistry GEX CART19, produced from a healthy human donor, were infused into OCI-Ly18 bearing mice. In model 1: on day -10, 5 × 1e6 luciferase+ OCILy18 cells were implanted subcutaneously into NSG mice. On day 0, 4 × 1e6 cells WT (n=8 mice) or BTLA KO (n=6 mice) CART19 cells were infused into tumor bearing mice. On day 16, mice were bled via retro-orbital sinus; human T cells from individual mice were barcoded, pooled based on condition (WT or BTLA KO) and sorted via FACS (CD3+CD2+CD5+). In model 2: 5 × 1e6 OCI-Ly18 were implanted into NSG mice on day -14. Then, on day 0, 4 × 1e6 WT (n=2 mice) or BTLA KO (n=2 mice) CART19 were infused via tail vein. On day 11 post-infusion, tumors were resected, minced, and filtered (70 µm & 40 µm). Mice tumor suspensions were pooled per condition (2 per arm); TILs were then sorted via FACS (CD2+CD5+).