T helper 17 cell (Th17) (Th17)

T helper 17 (Th17) cells are a specialized subset of CD4+ T lymphocytes characterized by their production of pro-inflammatory cytokines, including IL-17A, IL-17F, and IL-22 [PubMed: 17291286]. Their development is governed by the master transcription factor RORγt and is induced by a specific cytokine environment containing TGF-β, IL-6, and IL-23 [PubMed: 28435039]. While Th17 cells are critical for mucosal immunity and defense against extracellular bacteria and fungi, their dysregulation is a primary driver in the pathogenesis of chronic inflammatory and autoimmune diseases such as psoriasis, rheumatoid arthritis, and multiple sclerosis [PubMed: 30107052]. In drug discovery, the Th17 pathway is targeted using monoclonal antibodies like secukinumab or ixekizumab to neutralize effector cytokines, or agents like guselkumab that block the IL-23 survival signal [PubMed: 28247072]. Although highly effective in treating inflammation, inhibiting Th17 function compromises mucosal barriers, leading to a notable risk of fungal infections like Candidiasis [PubMed: 26364239]. Circulating Th17 cell levels are frequently monitored as biomarkers for disease activity and therapeutic response in clinical settings.

Other names

Th17 cellIL-17-producing CD4+ T cellType 17 helper T cellCirculating Th17 cells

Therapeutic agents modulate this cell population by either neutralizing the effector cytokines they produce (such as IL-17A or IL-17F) or by blocking upstream cytokines like IL-23 that are required for their differentiation, survival, and expansion [PubMed: 28247072].