1100 Elevation of TARC by anti-IL-31 receptor antibody in a murine atopic dermatitis model

Interleukin (IL)-31 is a key cytokine that contributes to pruritus in atopic dermatitis (AD). Recently, the treatment with anti-IL-31 receptor alpha (RA) antibody exhibited remarkable antipruritic effect AD patients. In clinical trial, serum levels of thymus activation-regulated chemokine (TARC), biomarker AD, were unexpectedly increased some patients treated anti-IL-31RA antibodies, without any exacerbation AD. However, mechanism elevated TARC after unknown. To clarify this mechanism, using calcipotriol (MC903)-induced mouse model, we found expression IL-31 skin and serum. After topical application MC903 for 7 days, administered or isotype control intraperitoneally. On day 14, level antibody-treated group was significantly higher than group. We also anti-IL31RA but not draining lymph nodes spleen. Furthermore, MC903-applied separated into epidermis dermis dispase homogenate supernatant quantified, indicating dermal cells main producer when antibody. Taken together, demonstrated increase murine model. Further study needed identify TARC-producing cells, such as dendritic macrophages, fibroblasts, endothelial during treatment.