Intrapatient comparison of atopic dermatitis skin transcriptome shows differences between tape-strips and biopsies.

BACKGROUND: Our knowledge of etiopathogenesis of atopic dermatitis (AD) is largely derived from skin biopsies, which are associated with pain, scarring and infection. In contrast, tape-stripping is a minimally invasive, nonscarring technique to collect skin samples. METHODS: To construct a global AD skin transcriptomic profile comparing tape-strips to whole-skin biopsies, we performed RNA-seq on tape-strips and biopsies taken from the lesional skin of 20 moderate-to-severe AD patients and the skin of 20 controls. Differentially expressed genes (DEGs) were defined by fold-change (FCH) ≥2.0 and false discovery rate <0.05. RESULTS: We detected 4104 (2513 Up; 1591 Down) and 1273 (546 Up; 727 Down) DEGs in AD versus controls, in tape-strips and biopsies, respectively. Although both techniques captured dysregulation of key immune genes, tape-strips showed higher FCHs for innate immunity (IL-1B, IL-8), dendritic cell (ITGAX/CD11C, FCER1A), Th2 (IL-13, CCL17, TNFRSF4/OX40), and Th17 (CCL20, CXCL1) products, while biopsies showed higher upregulation of Th22 associated genes (IL-22, S100As) and dermal cytokines (IFN-γ, CCL26). Itch-related genes (IL-31, TRPV3) were preferentially captured by tape-strips. Epidermal barrier abnormalities were detected in both techniques, with terminal differentiation defects (FLG2, PSORS1C2) better represented by tape-strips and epidermal hyperplasia changes (KRT16, MKI67) better detected by biopsies. CONCLUSIONS: Tape-strips and biopsies capture overlapping but distinct features of the AD molecular signature, suggesting their respective utility for monitoring specific AD-related immune, itch, and barrier abnormalities in clinical trials and longitudinal studies.

Oral prednisone regulates human skin T cells in delayed-type hypersensitivity reaction elicited by diphencyprone.

BACKGROUND: The potential benefit of inducing delayed-type hypersensitivity (DTH) reaction in healthy volunteers (HVs) as experimental models to study skin inflammatory disorders was recently reported using bulk molecular technologies. Immunophenotype of skin T cells, including cellular source of Type 1, 2, and 3 cytokines, in a local DTH reaction and their modulation by oral drugs remain to be investigated. METHOD: Purified protein derivative (PPD), nickel, diphencyprone (DPCP), or house dust mite (HDM) was administered as sensitizer to 40 HVs. In addition, 20 HVs were randomized to receive oral prednisone or placebo before DPCP challenge. We characterized the immunophenotype and cytokine profile of CD3+ T cell infiltrate, and examined the modulation by oral prednisone at single-cell level using multiparameter flow cytometry and unsupervised analysis. RESULTS: PPD was biased toward a Th1 and Tc1 response, and HDM a Th2/Th17 and Tc2. Nickel and DPCP displayed a mixed Th1/Th2/Th17 and Tc1 response. CD4+ CD25+ FoxP3+ regulatory T cells (Tregs), the minor CD4+ CD25+ FoxP3- ICOS+ PD-1+ (activated PD-1+ Th), and CD103+ tissue resident memory (TRM) cells were detected in all groups. DPCP uniquely elicited rare CD8+ CD103+ CD25+ RoRγt+ PD-1+ ICOS+ IFNγ+ T cells (activated CD8+ IFNγ+ PD-1+ TRM). Oral prednisone decreased frequencies of activated PD-1+ Th and CD8+ IFNγ+ PD-1+ TRM subsets relative to placebo in DPCP reaction. The latter was positively correlated with improvement of clinical parameters with prednisone. CONCLUSION: DTH and skin CD3+ T cell profiles elicited by common sensitizers can be modulated by oral drugs. Corticosteroids reduce the frequencies of activated PD-1+ Th and CD8+ IFNγ+ PD-1+ TRM cells after DPCP exposure.

Delayed type hypersensitivity reactions to various allergens may differently model inflammatory skin diseases.

BACKGROUND: Treatment of inflammatory skin diseases, including atopic dermatitis (AD) and psoriasis, is undergoing transformative changes, highlighting the need to develop experimental models of skin inflammation in humans to predict treatment responses. METHODS: We topically or intradermally administered four common sensitizers (dust mite (DM), diphencyprone (DPCP), nickel (Ni), and purified protein derivative (PPD)) to the backs of 40 healthy patients and the skin hypersensitivity response was biopsied and evaluated using immunohistochemistry, RNA-seq, and RT-PCR. RESULTS: All agents induced strong increases in cellular infiltrates (T-cells and dendritic cells) as compared to untreated skin (p < .05), with variable T helper polarization. Overall, DPCP induced the strongest immune responses across all pathways, including innate immunity (IL-1α, IL-8), Th1 (IFNγ, CXCL10), Th2 (IL-5, CCL11), and Th17 (CAMP/LL37) products, as well as the highest regulatory tone (FOXP3, IL-34, IL-37) (FDR <0.01). Nickel induced Th17 (IL-17A), Th1 (CXCL10) and Th2 (IL-4R) immune responses to a lesser extent than DPCP (p < .05). PPD induced predominantly Th1 (IFNγ, CXCL10, STAT1) and Th17 inflammation (IL-17A) (p < .05). DM induced modulation of Th2 (IL-13, CCL17, CCL18), Th22 (IL-22), and Th17/Th22 (S100A7/9/12) pathways (p < .05). Barrier defects that characterize both AD and psoriasis were best modeled by DPCP and Ni, followed by PPD, including downregulation of terminal differentiation (FLG, FLG2, LOR, LCEs), tight junction (CLDN1/CLDN8), and lipid metabolism (FA2H, FABP7)-related markers. CONCLUSION: Our data imply that DPCP induced the strongest immune response across all pathways, and barrier defects characteristic of AD and psoriasis.

A novel nonsense mutation in exon 9 in the extracellular matrix protein 1 gene associated with lipoid proteinosis: A case report.

Lipoid proteinosis is a rare autosomal recessive genodermatosis that is caused by loss-of-function mutations in the extracellular matrix protein 1 gene. This study identifies a novel nonsense mutation in exon 9 of the extracellular matrix protein 1 gene associated with lipoid proteinosis, contributing to recent advances in our understanding of the molecular genetics underlying this disease. It is important to identify the mutations in the extracellular matrix protein 1 gene that are associated with lipoid proteinosis and how these affect protein function. Understanding the molecular basis for such genetic disorders may lead to novel therapeutic approaches for treating hereditary genodermatoses.