Protein Kinase Inhibitors CK59 and CID755673 Alter Primary Human NK Cell Effector Functions

Area of Science:

• Immunology
• Cell Biology
• Pharmacology

Background:

• Natural killer (NK) cells are vital for innate immunity against tumors and viral infections.
• Kinases are crucial in cellular signaling and are targets for drug development, with some kinase inhibitors used in immunotherapy.
• Calmodulin kinase II (CaMKII) and PKD family kinases were previously implicated in NK cell activation pathways.

Purpose of the Study:

• To investigate the effects of specific kinase inhibitors, CK59 (targeting CaMKII) and CID755673 (targeting PKD family kinases), on NK cell effector functions.
• To validate the roles of CaMKII and PKD family kinases in NK cell signaling and activation.

Main Methods:

• Utilized a multi-parameter, fluorescence-activated cell sorting (FACS)-based assay.
• Tested the impact of CK59 and CID755673 on primary NK cells isolated from healthy blood donors.
• Assessed NK cell degranulation markers and cytokine release following inhibitor treatment.

Main Results:

• Both CK59 and CID755673 significantly reduced NK cell degranulation and cytokine release in a dose-dependent manner.
• These effects were observed in freshly isolated peripheral blood mononuclear cells.
• Donor-to-donor variations in NK cell response to kinase inhibition were noted in pure NK cell populations.

Conclusions:

• Calmodulin kinase II (CaMKII) is confirmed as important for NK cell signaling.
• Protein kinase D2 is suggested as a novel signaling component involved in NK cell activation.
• Kinase inhibition presents a potential strategy for modulating NK cell activity, though individual responses vary.