Figure 3.

BLU4565, BLU0556, and BLU7482 modulation of IL-2 release. C57BL/6 splenocytes were incubated with plate bound anti-CD3 (Clone 145-2C11, 1 µg/mL) in the presence of DMSO or different concentrations of STK17B inhibitor in 96-well in triplicate. After 24 hours, IL-2 secretion was measured in supernatants to assess the ability of compounds to enhance T cell activation (top panel). In parallel, OT-1 splenocytes were incubated with 1 µg/mL SIINFEKL peptide in the presence of DMSO or different concentrations of STK17B inhibitors and cultured for 96 hours. Cell-titer glow measurements assessed any off-target activity that inhibits proliferation (bottom panel). The aim was to identify potent compounds with a wide window between IL-2 induction and inhibition of proliferation – with BLU7482 reaching a 163× window. Representative of n=3 experiments is shown. CD, cluster of differentiation; CTG, CellTiter-Glo; DMSO, dimethyl sulfoxide; EC₅₀, half maximal effective concentration; IC₅₀, half maximal inhibitory concentration; IL-2, interleukin-2.