Figure 6. Chk1 inhibition does not interfere with T-cell–mediated killing of melanoma cells.

(A) 33F8-luciferase expressing melanoma cells were treated with indicated Chk1 inhibitors in the absence or presence of autologous TILs (1:1 or 3:1 TILs vs melanoma cells). Luciferin was added and viability was measured in a 96-well plate luminometer. (A, B) The same experimental setup as in (A) but using HER2-directed CAR-T cells instead of TILs. (C) 33F8 cells were mixed with autologous TILs in the presence of indicated inhibitors. Surface expression of CD107a as a marker of T-cell degranulation was determined by flow cytometry. (D) NOD/SCID/IL2 receptor gamma knockout mice transgenic for human interleukin-2 (hIL2-NOG mice) were transplanted with 33F8-luciferase melanoma cells. When tumors were detectable by IVIS imaging, TILs were injected and mice were dosed in indicated groups of animals (n = 4). Mice were followed with IVIS imaging until tumor size reached the ethics limit (10 mm on the shortest side). Shown are median IVIS signal and standard error of the mean.