Th22 Cells Contribution in Immunopathogenesis of Rheumatic Diseases.

Newly identified T helper cell 22 (Th22) is a subset of CD4+T cells with specific properties apart from other known CD4+ T cell subsets with distinguished gene expression and function. Th22 cells are characterized by production of a distinct profile of effector cytokines, including interleukin (IL)-22, IL-13, and tumor necrosis factor-α (TNF-α). The levels of Th22 and related cytokine IL-22 are increased in various autoimmune diseases and positively associated with some rheumatic diseases such as rheumatoid arthritis, systemic lupus erythematosus, behcet's disease, ankylosing spondylitis and psoriatic arthritis. In summary, IL-22 and Th22 cells play a significant and complicated role in inflammatory and autoimmune rheumatic diseases, therefore, targeting IL-22 or Th22 have unique and attractive advantages due to the fact that Th22 subset is recently identified and its associated research is extremely limited. This review discusses the role of Th22 and its cytokine IL-22 in the immunopathogenesis of rheumatic disease.

T-helper 22 cells as a new player in chronic inflammatory skin disorders.

T-helper 22 (Th22) cell is a new subset of CD4+ T cells that secrets interleukin (IL)-22 but not IL-17 or interferon-γ. Th22 is distinct from Th17 and other known CD4+ T-cell subsets with distinguished gene expression and function. Th22 subsets have chemokine receptors CCR6+ CCR4+ CCR10+ phenotype and aryl hydrocarbon receptor as the key transcription factor. This T-helper subset, by producing cytokines such as IL-22, IL-13, and tumor necrosis factor-α, is implicated in the pathogenesis of inflammatory skin disorder. This review discusses the role of Th22 and its cytokine IL-22 in the immunopathogenesis of inflammatory skin disorders such as psoriasis and atopic dermatitis.