Filaggrin-null mutations are associated with increased maturation markers on Langerhans cells.
Leitch Claire S,Natafji Eenass,Yu Cunjing,Abdul-Ghaffar Sharizan,Madarasingha Nayani,Venables Zoë C,Chu Roland,Fitch Paul M,Muinonen-Martin Andrew J,Campbell Linda E,McLean W H Irwin,Schwarze Jürgen,Howie Sarah E M,Weller Richard B
The Journal of allergy and clinical immunology
BACKGROUND:Mutations in the gene encoding filaggrin (FLG), an epidermal structural protein, are the strongest risk factor identified for the development of atopic dermatitis (AD). Up to 50% of patients with moderate-to-severe AD in European populations have FLG-null alleles compared with a general population frequency of 7% to 10%. OBJECTIVE:This study aimed to investigate the relationship between FLG-null mutations and epidermal antigen-presenting cell (APC) maturation in subjects with and without AD. Additionally, we investigated whether the cis isomer of urocanic acid (UCA), a filaggrin breakdown product, exerts immunomodulatory effects on dendritic cells. METHODS:Epidermal APCs from nonlesional skin were assessed by using flow cytometry (n = 27) and confocal microscopy (n = 16). Monocyte-derived dendritic cells from healthy volunteers were used to assess the effects of cis- and trans-UCA on dendritic cell phenotype by using flow cytometry (n = 11). RESULTS:Epidermal APCs from FLG-null subjects had increased CD11c expression. Confocal microscopy confirmed this and additionally revealed an increased number of epidermal CD83(+) Langerhans cells in FLG-null subjects. In vitro differentiation in the presence of cis-UCA significantly reduced costimulatory molecule expression on monocyte-derived dendritic cells from healthy volunteers and increased their ability to induce a regulatory T-cell phenotype in mixed lymphocyte reactions. CONCLUSIONS:We show that subjects with FLG-null mutations have more mature Langerhans cells in nonlesional skin irrespective of whether they have AD. We also demonstrate that cis-UCA reduces maturation of dendritic cells and increases their capacity to induce regulatory T cells, suggesting a novel link between filaggrin deficiency and immune dysregulation.
A mild topical steroid leads to progressive anti-inflammatory effects in the skin of patients with moderate-to-severe atopic dermatitis.
Brunner Patrick M,Khattri Saakshi,Garcet Sandra,Finney Robert,Oliva Margeaux,Dutt Riana,Fuentes-Duculan Judilyn,Zheng Xiuzhong,Li Xuan,Bonifacio Kathleen M,Kunjravia Norma,Coats Israel,Cueto Inna,Gilleaudeau Patricia,Sullivan-Whalen Mary,Suárez-Fariñas Mayte,Krueger James G,Guttman-Yassky Emma
The Journal of allergy and clinical immunology
BACKGROUND:Topical glucocorticosteroids are considered an efficient treatment option for atopic dermatitis (AD), but a global assessment of glucocorticosteroid responses on key disease circuits upon weeks to months of treatment is currently lacking. OBJECTIVE:We sought to assess short (4 weeks) and long-term (16 weeks) application of topical glucocorticosteroids on AD skin and define response biomarkers. METHODS:The effects of triamcinolone acetonide cream 0.025% were assessed based on gene expression and immunohistochemistry studies at baseline, 4 weeks, and 16 weeks in biopsy specimens from 15 patients with moderate-to-severe AD. RESULTS:At 16 weeks, only 3 patients were clinical responders (by using SCORAD50 criteria), but 6 patients qualified as responders based on histologic criteria. Baseline characteristics indicated more severe disease in nonresponders. While 3 of 15 patients experienced only transient benefit after 4 weeks, others showed progressive improvements toward 16 weeks. Topical glucocorticosteroid use in patients with AD resulted in improvements of the AD genomic signature of 25.6% at 4 weeks and 71.8% at 16 weeks, respectively, and even 123.9% in the histologic responder group. Cytokines (IL-12p40, IL-13, IL-22, CCL17, CCL18, peptidase inhibitor 3 [PI3]/elafin, and S100As) showed consistent decreases from baseline toward 16 weeks with corresponding improvements in epidermal disease hallmarks (keratin 16 and loricrin) in lesional skin from responders (P < .05). Nonresponders largely showed lesser/nonsignificant reductions in key inflammatory and barrier markers (keratin 16, IL-13, IL-22, CCL17, CCL18, PI3/elafin, S100As, and loricrin). The combination of IL-21 and IFN-γ baseline expression closely predicted individual clinical glucocorticosteroid responses at 16 weeks of treatment. CONCLUSION:Our study indicates that even low-potency glucocorticosteroids can broadly affect immune and barrier responses in patients with moderate-to-severe AD, associating higher baseline severity with increased steroid resistance in patients with AD.