Patricia Gilleaudeau

Response of psoriasis to a lymphocyte-selective toxin (DAB389IL-2) suggests a primary immune, but not keratinocyte, pathogenic basis

Psoriasis is a hyperproliferative and inflammatory skin disorder of unknown aetiology. A fusion protein composed of human interleukin-2 and fragments of diphtheria toxin (DAB389IL-2), which selectively blocks the growth of activated lymphocytes but not keratinocytes, was administered systemically to ten patients to gauge the contribution of activated T cells to the disease. Four patients showed striking clinical improvement and four moderate improvement, after two cycles of low dose IL-2–toxin. The reversal of several molecular markers of epidermal dysfunction was associated with a marked reduction in intraepidermal CD3+ and CD8+ T cells, suggesting a primary immunological basis for this widespread disorder.

Interleukin-11 therapy selectively downregulates type I cytokine proinflammatory pathways in psoriasis lesions

Psoriasis is a chronic inflammatory skin disease in which epidermal hyperplasia results from skin infiltration by type I T lymphocytes and release of associated cytokines. A multifunctional cytokine, rhIL-11, modulates macrophage and type I T-lymphocyte function in cell culture and shows anti-inflammatory activity in animal models. We are testing subcutaneous delivery of rhIL-11 to patients with psoriasis in a phase 1 open-label dose-escalation clinical trial. Tissue was obtained from lesional and uninvolved skin before and during treatment with rhIL-11 and was examined by histology/immunohistochemistry and quantitative RT-PCR. Expression of over 35 genes was examined in all patients, and multiple genetic markers of psoriasis were identified. Expression of numerous proinflammatory genes was elevated in psoriatic tissue compared with nonlesional skin. Seven of 12 patients responded well to rhIL-11 treatment. Amelioration of disease by rhIL-11, as shown by reduced keratinocyte proliferation and cutaneous inflammation, was associated with decreased expression of products of disease-related genes, including K16, iNOS, IFN-gamma, IL-8, IL-12, TNF-alpha, IL-1beta, and CD8, and with increased expression of endogenous IL-11. We believe that this is the first study in humans to indicate that type I cytokines can be selectively suppressed by an exogenous immune-modifying therapy. The study highlights the utility of pharmacogenomic monitoring to track patient responsiveness and to elucidate anti-inflammatory mechanisms.

Suberythemogenic narrow-band UVB is markedly more effective than conventional UVB in treatment of psoriasis vulgaris

BACKGROUND Narrow-band UVB (NB-UVB) is a new phototherapy option for psoriasis. Action spectrum studies previously done with different UVB wavelengths suggest that suberythemogenic doses of NB-UVB could be highly effective in treating psoriasis vulgaris. Even so, no comparative studies with suberythemogenic doses of NB versus conventional UVB have been performed previously. OBJECTIVE Our purpose was to compare conventional broad-band UVB (BB-UVB) with NB-UVB at suberythemogenic doses for the treatment of psoriasis vulgaris. METHODS Eleven patients were treated using a split-body approach for 6 weeks on a three-times-a-week basis. Outcomes were evaluated by means of Psoriasis Severity Index scores and quantitative histologic measures. RESULTS We were able to induce clinical clearing in 81.8% of patients after NB-UVB, but in only 9.1% of patients after BB-UVB (P < .01). Biopsy specimens obtained at the end of treatment revealed that keratin 16 staining was absent in 75% of patients on the NB side compared with none on the BB side, suggesting a reversal of regenerative epidermal hyperplasia by NB-UVB. CONCLUSION NB-UVB is superior to UVB-BB in reversing psoriasis at suberythemogenic doses when given three times per week. This schedule was well tolerated by all patients.

Molecular classification of psoriasis disease-associated genes through pharmacogenomic expression profiling

Psoriasis is recognized as the most common T cell-mediated inflammatory disease in humans. Genetic linkage to as many as six distinct disease loci has been established but the molecular etiology and genetics remain unknown. To begin to identify psoriasis disease-related genes and construct in vivo pathways of the inflammatory process, a genome-wide expression screen of multiple psoriasis patients was undertaken. A comprehensive list of 159 genes that define psoriasis in molecular terms was generated; numerous genes in this set mapped to six different disease-associated loci. To further interpret the functional role of this gene set in the disease process, a longitudinal pharmacogenomic study was initiated to understand how expression levels of these transcripts are altered following patient treatment with therapeutic agents that antagonize calcineurin or NF-κB pathways. Transcript levels for a subset of these 159 genes changed significantly in those patients who responded to therapy and many of the changes preceded clinical improvement. The disease-related gene map provides new insights into the pathogenesis of psoriasis, wound healing and cellular-immune reactions occurring in human skin as well as other T cell-mediated autoimmune diseases. In addition, it provides a set of candidate genes that may serve as novel therapeutic intervention points as well as surrogate and predictive markers of treatment outcome.

TNF-α Downregulates Filaggrin and Loricrin through c-Jun N-terminal Kinase: Role for TNF-α Antagonists to Improve Skin Barrier

Filaggrin (FLG), loricrin (LOR), and involucrin are important epidermal barrier proteins. As psoriasis is characterized by overexpression of tumor necrosis factor-α (TNF-α) and impaired skin barrier, we investigated the expression of skin barrier proteins in psoriasis patients and whether their expression was modulated by TNF-α. The expression of FLG and LOR was found to be decreased in lesional and non-lesional skin of psoriasis patients. A correlation was found between the expression of TNF-α and epidermal barrier proteins in psoriasis. TNF-α was found to modulate the expression of FLG and LOR via a c-Jun N-terminal kinase-dependent pathway. Importantly, we report that clinical treatment of psoriasis patients with a TNF-α antagonist results in significant enhancement of epidermal barrier protein expression. Our current study suggests that TNF inhibits barrier protein expression, and TNF-α antagonists may contribute to clinical improvement in patients with psoriasis by improving barrier protein expression.

Th17 cells and activated dendritic cells are increased in vitiligo lesions.

Background Vitiligo is a common skin disorder, characterized by progressive skin de-pigmentation due to the loss of cutaneous melanocytes. The exact cause of melanocyte loss remains unclear, but a large number of observations have pointed to the important role of cellular immunity in vitiligo pathogenesis. Methodology/Principal Findings In this study, we characterized T cell and inflammation-related dermal dendritic cell (DC) subsets in pigmented non-lesional, leading edge and depigmented lesional vitiligo skin. By immunohistochemistry staining, we observed enhanced populations of CD11c+ myeloid dermal DCs and CD207+ Langerhans cells in leading edge vitiligo biopsies. DC-LAMP+ and CD1c+ sub-populations of dermal DCs expanded significantly in leading edge and lesional vitiligo skin. We also detected elevated tissue mRNA levels of IL-17A in leading edge skin biopsies of vitiligo patients, as well as IL-17A positive T cells by immunohistochemistry and immunofluorescence. Langerhans cells with activated inflammasomes were also noted in lesional vitiligo skin, along with increased IL-1ß mRNA, which suggest the potential of Langerhans cells to drive Th17 activation in vitiligo. Conclusions/Significance These studies provided direct tissue evidence that implicates active Th17 cells in vitiligo skin lesions. We characterized new cellular immune elements, in the active margins of vitiligo lesions (e.g. populations of epidermal and dermal dendritic cells subsets), which could potentially drive the inflammatory responses.

Severe atopic dermatitis is characterized by selective expansion of circulating TH2/TC2 and TH22/TC22, but not TH17/TC17, cells within the skin-homing T-cell population

BACKGROUND Past studies of blood T-cell phenotyping in patients with atopic dermatitis (AD) have provided controversial results and were mostly performed before the identification of TH9, TH17, and TH22 T-cell populations in human subjects. OBJECTIVE We sought to quantify TH1, TH2, TH9, TH17, and TH22 T-cell populations and corresponding CD8(+) T-cell subsets in both cutaneous lymphocyte antigen (CLA)-positive and CLA(-) T-cell subsets in patients with AD and control subjects. METHODS We studied 42 adults with severe AD (mean SCORAD score, 65) and 25 healthy subjects using an 11-color flow cytometric antibody panel. Frequencies of IFN-γ-, IL-22-, IL-13-, IL-17-, and IL-9-producing CD4(+) and CD8(+) T cells were compared in CLA(-) and CLA(+) populations. RESULTS We measured increased TH2/TC2/IL-13(+) and TH22/TC22/IL-22(+) populations (P < .1) in patients with severe AD versus control subjects, with significant differences in CLA(+) T-cell numbers (P < .01). A significantly lower frequency of CLA(+) IFN-γ-producing cells was observed in patients with AD, with no significant differences in CLA(-) T-cell numbers. The CLA(+) TH1/TH2 and TC1/TC2 ratio was highly imbalanced in patients with AD (10 vs 3 [P = .005] and 19 vs 7 [P < .001], respectively). Positive correlations were found between frequencies of IL-13- and IL-22-producing CD4(+) and CD8(+) T cells (r = 0.5 and 0.8, respectively; P < .0001), and frequencies of IL-13-producing CLA(+) cells were also correlated with IgE levels and SCORAD scores. Patients with AD with skin infections had higher CD4(+) IL-22(+) and IL-17(+) cell frequencies, which were highly significant among CLA(-) cells (IL-22: 3.7 vs 1.7 [P < .001] and IL-17: 1.7 vs 0.6 [P < .001]), with less significant effects among CLA(+) T cells (IL-22: 11 vs 7.5, P = .04). CONCLUSIONS Severe AD is accompanied by expansion of skin-homing TH2/TC2 and TH22/TC22 subsets with lower TH1/TC1 frequencies. These data create a critical basis for studying alterations in immune activation in adults and pediatric patients with AD.

Cyclosporine in patients with atopic dermatitis modulates activated inflammatory pathways and reverses epidermal pathology.

BACKGROUND Atopic dermatitis (AD) is the most common inflammatory disease. Evolving disease models link changes in epidermal growth and differentiation to T(H)2/T(H)22 cytokine activation. However, these models have not been tested by in vivo suppression of T-cell cytokines. Cyclosporine (CsA) is an immunosuppressant that is highly effective for severe disease, but its mechanism in AD skin lesions has not been studied. OBJECTIVE We sought to establish the ability of a systemic immunosuppressant to modulate immune and epidermal alterations that form the pathogenic disease phenotype and to correlate changes with clinical improvement. METHODS CsAs effects on AD skin pathology were evaluated by using gene expression and immunohistochemistry studies in baseline, week 2, and week 12 lesional and nonlesional biopsy specimens from 19 patients treated with 5 mg/kg/d CsA for 12 weeks. RESULTS After 2 and 12 weeks of treatment, we observed significant reductions of 51% and 72%, respectively, in SCORAD scores. Clinical improvements were associated with significant gene expression changes in lesional but also nonlesional skin, particularly reductions in levels of T(H)2-, T(H)22-, and some T(H)17-related molecules (ie, IL-13, IL-22, CCL17, S100As, and elafin/peptidase inhibitor 3), and modulation of epidermal hyperplasia and differentiation measures. CONCLUSIONS This is the first study that establishes a relationship between cytokine activation and molecular epidermal alterations, as well as correlations between disease biomarkers in the skin and clinical improvement. The reversal of the molecular phenotype with CsA and the associated biomarkers can serve as a reference for the successful modulation of tissue inflammation with specific immune antagonists in future studies, contributing to the understanding of the specific cytokines involved in epidermal pathology.

Human Keratinocytes' Response to Injury Upregulates CCL20 and Other Genes Linking Innate and Adaptive Immunity

In the early stages of wound healing, keratinocytes become “activated” and release inflammatory molecules such as interleukin-1 and interleukin-8 that are linked to innate immune responses and neutrophil recruitment. It is unclear, however, whether keratinocytes release molecules linked to adaptive immune responses, e.g. CCL20, in their early state of activation without signals from infiltrating T cells. This study aims to isolate the immediate alterations in protective and inflammatory gene expression that occur in epidermal keratinocytes, with a particular focus on molecules associated with cell-mediated immunity. We used dispase-separated epidermis, followed by intercellular disassociation by trypsinization, as a model for epidermal injury. We obtained a pure population of keratinocytes using flow cytometry. As a control for uninjured epidermis, we performed laser capture microdissection on normal human skin. Sorted keratinocytes had an early burst of upregulated gene expression, which included CCL20, IL-15, IL-23A, IFN-κ, and several antimicrobial peptides. Our results provide insight into the potential role of keratinocytes as contributors to cell-mediated inflammation, and expand knowledge about gene modulation that occurs during early wound healing. Our findings may be relevant to cutaneous diseases such as psoriasis, where micro-injury can trigger the formation of psoriatic plaques at the site of trauma.

Efficacy and safety of ustekinumab treatment in adults with moderate-to-severe atopic dermatitis.

Atopic dermatitis (AD) is the most common inflammatory skin disease, but treatment options for moderate‐to‐severe disease are limited. Ustekinumab is an IL‐12/IL‐23p40 antagonist that suppresses Th1, Th17 and Th22 activation, commonly used for psoriasis patients. We sought to assess efficacy and safety of ustekinumab in patients with moderate‐to‐severe AD. In this phase II, double‐blind, placebo‐controlled study, 33 patients with moderate‐to‐severe AD were randomly assigned to either ustekinumab (n=16) or placebo (n=17), with subsequent crossover at 16 weeks, and last dose at 32 weeks. Background therapy with mild topical steroids was allowed to promote retention. Study endpoints included clinical (SCORAD50) and biopsy‐based measures of tissue structure and inflammation, using protein and gene expression studies. The ustekinumab group achieved higher SCORAD50 responses at 12, 16 (the primary endpoint) and 20 weeks compared to placebo, but the difference between groups was not significant. The AD molecular profile/transcriptome showed early robust gene modulation, with sustained further improvements until 32 weeks in the initial ustekinumab group. Distinct and more robust modulation of Th1, Th17 and Th22 but also Th2‐related AD genes was seen after 4 weeks of ustekinumab treatment (i.e. MMP12, IL‐22, IL‐13, IFN‐γ, elafin/PI3, CXCL1 and CCL17; P<.05). Epidermal responses (K16, terminal differentiation) showed faster (4 weeks) and long‐term regulation (32 weeks) from baseline in the ustekinumab group. No severe adverse events were observed. Ustekinumab had clear clinical and molecular effects, but clinical outcomes might have been obscured by a profound “placebo” effect, most likely due to background topical glucocorticosteroids and possibly insufficient dosing for AD.