Interferon kappa (IFNK)

Interferon kappa is a **type I interferon cytokine** encoded by the IFNK gene on human chromosome 9[1][2][5]. It has approximately 30% homology to other type I interferons and a conserved structure typical of this family, with a signal peptide and conserved cysteines[2][4][5]. IFN-kappa is selectively expressed in keratinocytes (main epidermal cells)[2] and is upregulated in response to viral infection, double-stranded RNA, or treatment with other interferons[2]. Its biological activity is mediated by high-affinity binding to the **type I interferon receptor** (IFNAR1/2), triggering the **JAK-STAT** signaling cascade and induction of hundreds of interferon-stimulated genes that orchestrate antiviral, pro-apoptotic, and immunomodulatory functions[1][2][4][5]. IFN-kappa is unique among type I interferons in its restricted tissue distribution (primarily skin/epithelial tissues) and evolutionary conservation in mammals[1]. Aberrant regulation, such as epigenetic silencing of the IFNK gene by HPV infection, is implicated in immune evasion and progression to cervical cancer[1]. Direct recombinant IFN-kappa confers species-specific protection against viral infection in vitro[2]. While no drugs directly target IFN-kappa clinically, it remains a key molecule of interest in antiviral, immune, and cancer biology, especially related to epithelial immunity and HPV pathogenesis[1][2][5][6].

Other names

IFNKIFN-kappaInterferon kappaUNQ6124/PRO20084IFNT1INFE1interferon-like protein

Activation of JAK-STAT signaling via type I interferon receptor (IFNAR1/IFNAR2), leading to gene expression of interferon-stimulated genes (ISGs) and increased antiviral response Modulation of MAPK and PI3K/AKT pathways