Interleukin-12 receptor signaling complex (IL-12R)

The Interleukin-12 (IL-12) receptor signaling complex is a heterodimeric type I cytokine receptor primarily composed of two subunits, IL-12Rβ1 and IL-12Rβ2, which are expressed on the surface of activated T cells and natural killer (NK) cells [1, 3]. Upon binding its ligand, the heterodimeric cytokine IL-12 (p35/p40), the receptor complex undergoes a conformational change that activates associated Janus kinases, specifically JAK2 and TYK2 [2, 5]. These kinases subsequently phosphorylate the signal transducer and activator of transcription 4 (STAT4), which dimerizes and translocates to the nucleus to drive the expression of pro-inflammatory genes, most notably interferon-gamma (IFN-γ) [2, 12]. This signaling pathway is a critical driver of Th1 cell differentiation and the enhancement of cell-mediated immunity, making it essential for defense against intracellular pathogens and tumors [7, 15]. In clinical practice, the IL-12 receptor signaling complex is a major therapeutic target for autoimmune and inflammatory diseases such as psoriasis and Crohn's disease, where drugs like ustekinumab prevent receptor activation by targeting the shared p40 subunit of the IL-12 and IL-23 ligands [9, 11]. Conversely, recombinant IL-12 and gene therapy approaches aim to activate this complex to stimulate anti-tumor immune responses, although systemic toxicity remains a significant challenge [14, 17].

Other names

Interleukin-12 receptorIL-12RIL-12Rβ1/IL-12Rβ2 complexCD212IL-12 receptor complex

Inhibition of IL-12/IL-23 signaling by targeting the shared p40 subunit (e.g., ustekinumab) or downstream JAK/STAT kinases (e.g., deucravacitinib); or activation of the receptor complex using recombinant IL-12 to stimulate anti-tumor immunity [2, 11, 12, 14].