IL-2-inducible T-cell kinase (ITK) (ITK)

IL-2-inducible T-cell kinase (ITK) is a non-receptor tyrosine kinase belonging to the TEC family, predominantly expressed in T cells and natural killer (NK) cells (UniProt: P42681). It serves as a crucial mediator in the T-cell receptor (TCR) signaling pathway, where it is recruited to the plasma membrane and activated following TCR engagement (PubMed: 25594891). Once active, ITK phosphorylates phospholipase C-gamma-1 (PLC-gamma-1), leading to calcium mobilization and the activation of downstream transcription factors such as NFAT, which drive T-cell proliferation and cytokine production (NCBI Gene: 3702). ITK is particularly vital for the differentiation and effector functions of Th2, Th17, and Th9 cells, linking it to the pathogenesis of allergic asthma and various autoimmune conditions (PubMed: 28213224). In oncology, ITK is often involved in T-cell lymphomas, and its inhibition is explored as a strategy to modulate the immune microenvironment (ClinicalTrials.gov: NCT03952078). While some approved drugs like ibrutinib inhibit ITK as an off-target effect, selective ITK inhibitors are currently in clinical development to provide more targeted immunomodulation with reduced side effects (PubMed: 33093354).

Other names

Interleukin-2-inducible T-cell kinaseTyrosine-protein kinase ITK/TSKT-cell-specific kinaseEMTPSCTK2

Inhibition of ITK kinase activity blocks the phosphorylation of PLC-gamma-1, preventing downstream calcium signaling and T-cell activation.