Recent findings underscore an important role of IL-31/IL-31RA signalling in pruritus. The novel TH2-derived cytokine interleukin-31 (IL-31) has been implicated in the pathophysiology of atopic dermatitis (AD) and induces pruritus via a synergistic cooperation of dysregulated immune cells and stimulated sensory neurons. In particular, the clinical efficacy of the IL-31RA-targeting antibody nemolizumab in treating itch in atopic dermatitis patients emphasized the importance of the IL-31/IL-31RA pathway. Although type 2 memory T cells (TH2) are considered to be the major source of IL-31 production, the phenotype IL-31-producing T cells is poorly characterized. In the present study, we established a reliable protocol for intracellular IL-31 staining in restimulated T cells and investigated the detailed phenotype of IL-31-producing T cells in AD patients (n=30) and healthy volunteers.

The IL-31-producing circulating T cells subset represents a unique population of CLA+ CRTH2+ CCR4+ effector memory T cells