**2.1 Cell lines and reagents**

The kinase inhibitor library (Cayman, Cat#10505) used for the screening assay has 152 known kinase inhibitors at 10 mM stock concentration in DMSO. The fluorescent antibodies against CD3, CD4, CD8, CD69, CD25 and HLA-DR, cell viability dye, cell proliferation tracing dye, cytokine capture beads (iQue QBeads®, Sartorius) and the cytokine detection reagents used in this study are from the iQue® Human T Cell Activation Kit (iQue® Sartorius, Cat#90561). Human PBMCs (Astarte Biologics, Cat#1001) from healthy donors were stimulated/activated with either T-activator CD3/CD28 Dynabeads® (ThermoFisher, Cat#11131D) or phytohemagglutinin (PHA, Sigma, Cat#L8754), or Enterotoxin Type B from *Staphylococcus aureus* (SEB, List Biological Laboratories, Cat#122). Cells were cultured in RMPI-1640 (VWR, Cat#45000–396) with 10% fetal bovine serum (VWR, Cat#97068–085) and supplements that included non-essential amino acids (VWR, Cat#12001–634), sodium pyruvate (VWR, Cat#45000–710), and penicillin–streptomycin (VWR, Cat#12001–692).
