TYK2 in Immune Responses and Treatment of Psoriasis

Tyrosine kinase 2 (TYK2), a key part of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, plays an integral role in the differentiation and immune responses of intrinsic immune cells and regulates the mediation of cytokines. TYK2 leads to inflammatory cascade responses in the pathogenesis of immune-mediated inflammatory diseases (IMIDs), especially psoriasis. Small-molecule TYK2 inhibitors are considered to be an effective strategy for modulating psoriasis. Here, we attempt to review the pro-inflammatory mechanisms of the JAK-STAT signaling pathway, the regulatory roles of TYK2 in the pathogenesis of psoriasis, and provide updates on ongoing and recently completed trials of TYK2 inhibitors.