House dust mite allergens Der f and Der p induce IL-31 production by blood-derived T cells from atopic dermatitis patients.

Aero-allergens, such as house dust mite (HDM), have been suggested to play a role in the initiation of atopic dermatitis (AD)-related skin inflammation. Here, we analysed the proliferation and the cytokine expression of blood-derived T cells from AD and healthy individuals upon HDM-allergen stimulation. The proliferating cells from healthy individuals and AD patients had a significantly different, distinct cytokine profile: in AD blood, we found increased frequencies of HDM-reactive IL-31-producing T cells, as well as a decreased Th1/Th2 and Tc1/Tc2 ratio, suggesting that allergen-specific T cells in blood of chronic AD patients are subject to pre-existent Th2-Tc2 and "Th31-Tc31" programming.