416 No difference in UVB induced changes in antigen presenting cells and cytokines between subjects with and without FLG null-mutation

Abstract

Epidermal filaggrin deficiency may affect UVB induced immune responses. We examined if common filaggrin gene (FLG) null-mutations were associated with altered responses in antigen presenting cells and cytokines following UVB irradiation of human skin in vivo. Atopic heterozygotic FLG null-mutation carriers and healthy wildtype subjects(WT) were included. Skin on the volar forearm was irradiated with 1.5 minimal erythema dose UVB. Suction blisters were raised on skin irradiated 24 and 72 hours earlier and on non-irradiated control skin(C). Antigen presenting cell numbers and activation markers were examined in epidermal single cell suspensions by flow cytometry. Concentrations of IL-1β, IL-6, IL-10, IL-12p70, TNF-α, TGF-β1, and CCL20 were measured in blister fluid. As expected, UVB irradiation caused a significant decrease in Langerhans cell (LC) numbers, a significant increase in monocyte numbers, and a significant upregulation of activation markers CD86 and OX40 ligand on LCs. These changes did not differ between heterozygotic and WT subjects: deltaLC 24hrs - C; P=0.44, deltaLC 72hrs - C; P=0.20, deltaMonocytes 24hrs - C; P=0.19, deltaMonocytes 72hrs - C; P=0.38, deltaCD86 24hrs - C; P=0.38, deltaCD86 72hrs - C; P=0.10, deltaOX40L 24hrs - C; P=0.28, deltaOX40L 72hrs - C; P=0.51(N=8+8). UVB irradiation upregulated IL-1β, IL-6, and TGF-β1, but these changes were not influenced by FLG mutation status either: deltaIL-1β 24hrs - C; P=0.84(N=5+6), deltaIL-1β 72hrs - C; P>0.99(N=5+6), deltaIL-6 24hrs - C; P=0.91(N=5+6), deltaIL-6 72hrs - C; P=0.91(N=5+6), deltaTGF-β1 24hrs - C; P=0.96(N=5+7), deltaTGF-β1 72hrs - C; P=0.43(N=5+7). Taken together, we found no difference in changes of antigen presenting cells and cytokines in UVB irradiated skin from subjects with and without a FLG null-mutation.