Inhibitor of nuclear factor kappa-B kinase subunit beta - Interferon regulatory factor 5 signaling axis (IKKβ-IRF5)

The IKKβ-IRF5 axis refers to the signaling pathway where the kinase Inhibitor of nuclear factor kappa-B kinase subunit beta (IKKβ) phosphorylates the transcription factor Interferon regulatory factor 5 (IRF5). This phosphorylation event, specifically at the C-terminal region (Ser462), is a prerequisite for IRF5 dimerization, nuclear translocation, and the subsequent transcriptional activation of genes encoding Type I interferons and pro-inflammatory cytokines such as TNF-α and IL-6 (Ren et al., 2014, Nat. Immunol.). This pathway is a critical component of the Toll-like receptor (TLR) and MyD88-dependent innate immune response. Dysregulation of the IKKβ-IRF5 axis is strongly implicated in the pathogenesis of autoimmune diseases, particularly systemic lupus erythematosus (SLE), where IRF5 is considered a master regulator of the interferon signature that drives chronic inflammation (Eames et al., 2016, Ann. Rheum. Dis.). Therapeutic targeting of this axis primarily focuses on small molecule inhibitors of IKKβ, such as SAR113945 and TPCA-1, which aim to dampen the overactive inflammatory response. However, because IKKβ is also a central mediator of the canonical NF-κB pathway, safety concerns regarding broad immunosuppression and systemic toxicity remain significant challenges in clinical development (Dieguez-Gonzalez et al., 2014, Arthritis Res. Ther.). Current research continues to explore more selective ways to modulate this axis to minimize off-target effects while maintaining therapeutic efficacy.

Other names

IKK2-IRF5 axisIKK-beta/IRF5 signaling pathwayIKBKB-IRF5 axis

Inhibition of IKKβ-mediated phosphorylation of IRF5 to prevent its activation and downstream pro-inflammatory gene transcription.