Cutaneous EBV‐positive γδ T‐cell lymphoma vs. extranodal NK/T‐cell lymphoma: a case report and literature review

Primary cutaneous γδ T‐cell lymphoma and extranodal natural killer (NK)/T‐cell lymphoma (ENKTL), nasal type are two distinct lymphoma entities in the World Health Organization (WHO) classification. We report the case of an aggressive cutaneous lymphoma of γδ T‐cell origin showing overlapping features of both lymphomas. A 78‐year‐old female presented with confluent erythematous plaques with ulcerations over her right thigh. Microscopically, section of the skin showed a diffuse dermal and subcutaneous lymphocytic infiltration with tumor necrosis and angioinvasion. The medium‐ to large‐sized tumor cells expressed CD3, CD8, cytotoxic molecules and T‐cell receptor (TCR)‐γ but not CD4, CD20, CD30, CD56 or βF1. In situ hybridization for Epstein‐Barr virus‐encoded mRNA (EBER) was diffusely positive. Polymerase chain reaction‐based clonality assay showed a clonal TCR‐γ chain gene rearrangement. The features compatible with γδ T‐cell lymphoma include dermal and subcutaneous involvements, cytotoxic phenotype, expression of TCR‐γ, as well as an aggressive course. On the other hand, the diffuse EBER positivity, angioinvasion, tumor necrosis and cytotoxic phenotype may also fit in the diagnosis of an ENKTL of T‐cell lineage. We review the literature on EBER‐positive γδ T‐cell lymphoma and discuss the diagnostic dilemma using the current WHO classification system.     

Tropisetron via α7 nicotinic acetylcholine receptor suppresses tumor necrosis factor‐α‐mediated cell responses of human keratinocytes

Tropisetron is a serotonin receptor (5‐HT‐R)‐modulating agent and approved as an antiemetic for patients undergoing chemotherapy. In the gut, it acts via specific serotonin receptors, 5‐HT₃‐R, to elicit its beneficial effects against nausea. We investigated whether tropisetron can affect inflammatory cell responses of human primary epidermal keratinocytes (NHK) which are key cells in the regulation of skin homoeostasis. Tropisetron significantly and dose‐dependently suppressed tumor necrosis factor (TNF)‐α‐mediated mRNA expression and protein secretion of interleukin (IL)‐6 and IL‐8 in these cells. This effect of tropisetron was independent of p65/NF‐κB as shown by various NF‐κB signal transduction read‐outs. Importantly, the anti‐inflammatory tropisetron effect on NHK was neither mediated by 5‐HT₃‐R nor 5‐HT₄‐R since these receptors were absent in NHK. In contrast, NHK expressed α7 nicotinic acetylcholine receptors (α7nAchR) which previously were found to bind tropisetron. The α7nAchR antagonist α‐bungarotoxin neutralized, whereas AR‐R17779, a specific α7nAchR agonist, mimicked the suppressive effect of tropisetron on TNF‐α‐mediated IL‐6 and IL‐8 expression in NHK. Our findings suggest that tropisetron and probably other α7nAchR‐activating agents could be useful for the future therapy of inflammatory skin diseases.     

Case of subepidermal autoimmune bullous disease with psoriasis vulgaris reacting to both BP180 C‐terminal domain and laminin gamma‐1

A number of cases of psoriasis vulgaris developing bullous skin lesions have been diagnosed as either bullous pemphigoid with antibodies to the 180‐kDa bullous pemphigoid antigen (BP180) non‐collagenous 16a (NC16a) domain or anti‐laminin‐γ1 (p200) pemphigoid. We report a case of subepidermal bullous disease with psoriasis vulgaris, showing antibodies to both BP180 C‐terminal domain and laminin‐γ1. A 64‐year‐old Japanese man with psoriasis vulgaris developed exudative erythemas and tense bullae on the whole body but he did not have mucosal involvement. The blistering lesion showed subepidermal blisters histopathologically. In indirect immunofluorescence of 1 mol/L NaCl‐split skin, immunoglobulin (Ig)G antibodies reacted with both the epidermal and dermal side. Immunoblotting showed positive IgG with recombinant protein of BP180 C‐terminal domain and 200‐kDa laminin‐γ1 in normal human dermal extract.     

Evidence for a regulatory loop between IFN‐γ and IL‐33 in skin inflammation

Interleukin‐33 has recently gained much attention due to its role in allergic responses. It has been shown to amplify Th2 responses and to act as a damage‐associated molecular pattern. IL‐33 acts on a broad range of cells and has been proposed to link innate and adaptive features of allergic responses. It was the aim of this study to investigate this property of IL‐33 in the inflammatory response characterising atopic dermatitis (AD). We have analysed the response of skin‐resident cells derived from patients with AD and healthy donors with regard to the expression of IL‐33 and its receptor ST2. The functional impact of IL‐33 on CD4+ T cells was investigated. Keratinocytes and dermal fibroblasts clearly differ in their regulation of IL‐33. In fibroblasts, the concerted action of TNF‐α and IL‐1β was the strongest inducer, whereas IFN‐γ is clearly the key molecule that upregulates IL‐33 in keratinocytes with a more pronounced response of cells derived from patients with AD. Keratinocytes from patients with AD showed a markedly higher constitutive expression level of surface ST2. CD4+ T cells respond to IL‐33. Unexpectedly, IL‐33 failed to induce a significant secretion of IL‐5 or IL‐13. By contrast, high amounts of IFN‐γ were detectable if IL‐33 was added to the T‐cell receptor‐stimulated cells or in combination with IL‐12. These results suggest that IL‐33 and IFN‐γ are closely interlinked in epidermal AD inflammation. IFN‐γ induces IL‐33 in keratinocytes and IL‐33 acts on activated T cells to further increase the release of IFN‐γ, therefore contributing to drive skin inflammation towards chronic responses.     

Increased alpha‐melanocyte‐stimulating hormone (α‐MSH) levels and melanocortin receptors expression associated with pigmentation in an NC/Nga mouse model of atopic dermatitis

Please cite this paper as: Increased alpha‐melanocyte‐stimulating hormone (α‐MSH) levels and melanocortin receptors expression associated with pigmentation in an NC/Nga mouse model of atopic dermatitis. Experimental Dermatology 2010; 19: 132–136. Abstract: Patients with a specific subtype of atopic dermatitis (AD) display particular patterns of pigmentation, such as ripple pattern pigmentation on the neck, pigmented macules on the lip and diffuse pigmentation. However, the mechanism underlying these patterns has not been determined. The purpose of our research is to investigate the factors influencing this type of pigmentation in AD. We observed that AD model mice (NC/Nga mice) displayed an increase in the number of 3, 4‐dihydroxyphenylalanine (Dopa)‐positive melanocytes in the epidermis and intestine (jejunum and colon) while in the inflammatory state. The plasma levels of alpha‐melanocyte‐stimulating hormone (α‐MSH) and adrenocoticotropin (ACTH) also increased in NC/Nga mice with dermatitis. Furthermore, the expression of melanocortin receptor 5 and melanocortin receptor 1 (MC1R) increased in the skin, and melanocortin receptor 3 (MC3R) expression increased in the intestine. However, the changes in the Dopa‐positive cells of conventional NC/Nga mice were not induced by treatment with either agouti (an MC1R antagonist) or agouti‐related protein (an MC3R antagonist). These results indicate that the pigmentation of AD is related to increased levels of α‐MSH, MC1R (in the skin) and MC3R (in the intestines).     

Effects of β‐carotene on oxazolone‐induced atopic dermatitis in hairless mice

Skin acts as a barrier, which protects internal tissues and promotes moisture retention. Atopic dermatitis (AD) is an inflammatory skin disease associated with a variety of genetic and environmental factors that involve helper T cells. β‐Carotene (provitamin A) exhibits antioxidant activity and activates the immune system. However, it is not clear whether inflammation in AD skin is improved by posttreatment with β‐carotene. In the current study, we investigated the effects of β‐carotene on the skin of hairless mice with oxazolone‐induced inflammation/oedema (Ox‐AD mice). We found that skin inflammation was significantly reduced by oral administration of β‐carotene. In addition, treatment with β‐carotene suppressed protein levels of TNF‐α, IL‐1β and MCP‐1, as well as mRNA expression associated with IL‐1β, IL‐6, IL‐4 and Par‐2 in skin tissues. Furthermore, the mRNA and protein levels of filaggrin, a structural protein in the epidermal stratum corneum, were elevated by β‐carotene administration as compared with Ox‐AD mice. β‐Carotene significantly reduced the activity of proMMP‐9, but not proMMP‐2. These results suggest that in Ox‐AD mice, β‐carotene improves skin inflammation by suppressing the expression of inflammatory factors, promoting filaggrin expression and reducing MMP‐9 activity. β‐Carotene is a potent anti‐inflammatory agent that improves the barrier functions of AD skin.     

Human skin melanocyte migration towards stromal cell‐derived factor‐1α demonstrated by optical real‐time cell mobility assay: modulation of their chemotactic ability by α‐melanocyte‐stimulating hormone

To identify potential regulators of normal human melanocyte behaviour, we have developed an in vitro human melanocyte migration assay, using the optically accessible, real‐time cell motility assay device TAXIScan. Coating of the glass surface with an extracellular matrix that served as scaffolding molecule was essential to demonstrate efficient melanocyte migration. Among several chemokines tested, stromal cell‐derived factor (SDF)‐1α/CXCL12 was the most effective driver of human normal skin melanocytes. Incubation of melanocytes with α‐melanocyte‐stimulating hormone (MSH) before the assay specifically enhanced CXCR4 expression and consequently chemotaxis towards SDF‐1α/CXCL12. These results suggest that α‐MSH acts on melanocytes to produce melanin as well as stimulates the cells to migrate to the site where they work through CXCR4 up‐regulation, which is a new dynamic mode of action of α‐MSH on melanocyte physiology.     

TNF‐α and IL‐10 gene polymorphisms show a weak association with pemphigus vulgaris in the Slovak population

Backround Pemphigus vulgaris is a rare chronic autoimmune disease of skin and mucous membranes, with several cytokines participating in its development. The role of their gene polymorphisms in susceptibility to the disease is, however, not fully understood. Objective The aim of our case‐control study was to investigate whether some of 22 single nucleotide polymorphisms (SNPs) in 13 cytokine genes (IL‐1α, IL‐1β, IL‐1RI, IL‐1Ra, IL‐4Rα, IL‐12, IFN‐γ, TGF‐β1, TNF‐α, IL‐2, IL‐4, IL‐6 and IL‐10) are associated with pemphigus vulgaris in the Slovak population. Methods DNA samples were obtained from 34 pemphigus vulgaris patients and 140 healthy controls of Slovak origin. Cytokine gene SNPs were determined using the polymerase chain reaction with sequence‐specific primers (PCR‐SSP) method. Results We found a weak association between pemphigus vulgaris and polymorphic variants in TNF‐α and IL‐10 genes only, with haplotypes TNF‐α–308G/–238G and IL‐10 –1082A/–819C/–592C being significantly overrepresented in pemphigus vulgaris patients (TNF‐α GG: 94.12% vs. 82.86%, P = 0.0216; IL‐10 ACC: 44.12% vs. 30.00%, P = 0.0309). Conclusions Our preliminary results suggest that certain TNF‐α and IL‐10 gene polymorphisms might contribute to genetic susceptibility to pemphigus vulgaris; however, their overall impact on disease development will be rather limited.     

Immunoglobulin G4‐related disease presenting with prurigo: Circulating T‐helper 2 cells may be involved in the pathogenesis

We report a case of immunoglobulin G4‐related disease (IgG4‐RD) which presented with prurigo on the trunk and extremities. A 66‐year‐old man had a 2‐month history of itchy erythematous papules on his trunk and extremities. Bilateral eyelid swelling and enlargement of the submandibular and parotid glands were also observed. Computed tomography revealed pleural thickening and diffuse pancreatic enlargement. Serum levels of IgG4 were markedly increased. A biopsy specimen obtained from an erythematous papule showed a perivascular inflammatory infiltrate of lymphocytes with eosinophils in the dermis, whereas a parotid gland biopsy revealed an infiltrate of abundant IgG4‐positive plasma cells. Treatment with prednisolone resulted in improvement of the skin and other lesions along with a decrease in IgG4 serum levels. A flow cytometric assay revealed that percentages of interleukin (IL)‐4‐ and IL‐13‐producing CD4⁺ T cells were markedly higher in the circulation of the IgG4‐RD patient than in that of healthy subjects. Moreover, those populations dramatically decreased after treatment. Thus, prurigo may be a skin manifestation of IgG4‐RD and T‐helper 2 cells may contribute to the pathogenesis.     

Secondary failure of TNF‐α inhibitors in clinical practice

Tumor necrosis factor alpha (TNF‐α) is a leading inflammatory cytokine that plays a pivotal role in the pathogenesis of psoriasis. In case of a severe course of psoriasis and moderate‐to‐severe disease in which traditional systemic treatments are ineffective or contraindicated, TNF‐α inhibitors (iTNF‐α) are used. This class of drugs includes monoclonal antibodies and a fusion protein (etanercept) and can induce a humoral or cell‐mediated immune response, leading to formation of anti‐drug antibodies (ADAs). The immunogenicity may affect iTNF‐α drug pharmacokinetics, which would lead to hampering the clinical response (secondary drug failure), so a need to increase the drug dose arises. Antibodies against monoclonal antibodies (adalimumab, infliximab) have been associated with diminished clinical response, while against etanercept are non‐neutralizing and appear to have no significant effect on clinical response and treatment safety. Switching of biologic agents may be one strategy in ADA‐associated secondary failure of iTNF‐α. However researches are needed to identify risk factors for ADA development and investigate management strategies for optimized treatment response. The authors reviewed the literature on the effectiveness of iTNF‐α and pointed out the prevention of secondary failure in clinical practice.     

Effective induction of melanoma‐antigen‐specific CD8+ T cells via Vγ9γδT cell expansion by CD56high+ Interferon‐α‐induced dendritic cells

Dendritic cells (DCs) can be differentiated from CD14⁺ monocytes in the presence of interferon‐α (IFNα) and granulocyte/macrophage‐colony stimulating factor (GM‐CSF) in vitro and are known as IFN‐DCs. Circulating blood CD56⁺ cells expressing high levels of CD14, HLA‐DR and CD86 have been shown to spontaneously differentiate into DC‐like cells in vitro after their isolation from blood. We show here that IFN‐DCs expressing high levels of CD56 (hereafter, CD56^high+ IFN‐DCs) can be differentiated in vitro from monocytes obtained as adherent cells from healthy donors and patients with metastatic melanoma. These cells expressed high levels of CD14, HLA‐DR and CD86 and possessed many pseudopodia. These CD56^high+ IFN‐DCs may be an in vitro counterpart of the circulating CD56⁺ CD14⁺ CD86⁺ HLA‐DR⁺ cells in blood. Conventional mature DCs differentiated from monocytes as adherent cells in the presence of GM‐CSF, IL‐4 and TNF‐α (hereafter, mIL‐4DCs) did not express CD56 or CD14. In contrast to mIL‐4DCs, the CD56^high+ IFN‐DCs exhibited a stronger capacity to stimulate autologous CD56⁺ Vγ9γδT cells highly producing IFNγ in the presence of zoledronate and IL‐2. The CD56^high+ IFN‐DCs possessing HLA‐A*0201 effectively induced Mart‐1‐modified melanoma peptide (A27L)‐specific CD8⁺ T cells through preferential expansion of CD56⁺ Vγ9γδT cells in the presence of A27L, zoledronate and IL‐2. Vaccination with CD56^high+ IFN‐DCs copulsed with tumor antigens and zoledronate may orchestrate the induction of various CD56⁺ immune cells possessing high effector functions, resulting in strong immunological responses against tumor cells. This study may be relevant to the design of future clinical trials of CD56^high+ IFN‐DCs‐based immunotherapies for patients with melanoma.     

Influence of tumour necrosis factor‐α polymorphism −308 and atopy on irritant contact dermatitis in healthcare workers*

Background. Chronic irritant hand dermatitis is an issue for healthcare workers and may negatively impact infection control. Objectives. We examined the effects of a G to A transition at position ?308 on the tumour necrosis factor‐α (TNF‐α) gene on chronically damaged skin of healthcare workers during exposure and recovery from repetitive hand hygiene, after intensive treatment, and on the irritant response in normal skin. Patients/Materials/Methods. In 68 healthcare workers with irritant hand dermatitis, we genotyped TNF‐α?308 and measured the epidermal response via quantitative digital imaging, erythema, dryness, and barrier integrity. Results. Excess hand erythema decreased with hand hygiene exposure and increased during time off for AA/GA genotypes, but had opposite effects for GG. AA/GA had smaller reductions in dryness with lotion treatment and larger reductions in excess erythema than GG. The atopic diathesis and heightened neurosensory irritation resulting from water and lactic acid significantly influenced the responses. Repeated exposure to water and sodium lauryl sulfate (0.05, 0.1%) produced higher erythema in normal skin for AA/GA than for GG. Conclusions. This study provides evidence that the TNF‐α polymorphism at ?308 and an atopic history impact the severity of irritation and recovery from exposure and response to treatment for common hand skin products in both chronic irritant hand dermatitis and normal skin.     

Interleukin‐1 from epithelial cells fosters T cell‐dependent skin inflammation

Background Chronic inflammatory skin diseases such as atopic dermatitis and psoriasis are characterized by the infiltration of lymphocytes into the epidermal compartment. Several studies point to an active role of skin epithelial cells in the pathophysiology of such diseases. Objectives In this study we addressed the regulatory function of primary human keratinocytes in the interaction with autologous T cells and monocytes. Methods We used a human coculture model with keratinocytes grown from epidermal stem cells of the outer root sheath of human hair follicles and autologous T cells. Results In our coculture system we observed a high production of interferon (IFN)‐γ, but not Th2 cytokines, in the presence of superantigen or antigen‐pulsed autologous monocytes. Critical parameters for this effect were: (i) T‐cell receptor activation, (ii) an intercellular adhesion molecule‐1/lymphocyte function‐associated antigen (LFA)‐1‐dependent interaction between keratinocytes and T cells, and (iii) secretion of interleukin (IL)‐1β. Remarkably, in the presence of activated T cells, epithelial cells seemed to be a more significant source of IL‐1β than monocytes. Application of the LFA‐1 blocker efalizumab or IL‐1 receptor antagonist anakinra enabled us to suppress completely the production of IFN‐γ by T cells in the coculture. Conclusions IL‐1 secretion and the physical contact between keratinocytes and activated, infiltrating T cells may be central for the development of chronic inflammatory skin conditions.     

S‐allyl cysteine inhibits TNF‐α‐induced inflammation in HaCaT keratinocytes by inhibition of NF‐ κB‐dependent gene expression via sustained ERK activation

Tumor necrosis factor‐α (TNF‐α)‐induced keratinocyte inflammation plays a key role in the pathogenesis of multiple inflammatory skin diseases. Here we investigated the anti‐inflammatory effect of S‐allyl cysteine (SAC) on TNF‐α‐induced HaCaT keratinocyte cells and the mechanism behind its anti‐inflammatory potential. SAC was found to inhibit TNF‐α‐stimulated cytokine expression. Further, SAC was found to inhibit TNF‐α‐induced activation of p38, JNK and NF‐κB pathways. Interestingly, SAC was found to differentially regulate ERK MAP kinase in cells. TNF‐α‐induced transient ERK activation and SAC treatment resulted in sustained ERK activation both in the presence and absence of TNF‐α. Additionally, SAC failed to inhibit the TNF‐α‐induced expression of the pro‐inflammatory cytokines TNF‐α and IL‐1β when cells were treated with the MEK inhibitor PD98059, suggesting that the anti‐inflammatory effect of SAC is via sustained activation of the ERK pathway. Since ERK activation has been reported to negatively regulate NF‐κB‐driven gene expression and we find that SAC activates ERK and negatively regulates NF‐κB, we investigated whether there existed any crosstalk between the ERK and the NF‐κB pathways. NF‐κB‐dependent reporter assay, visualization of the nuclear translocation of NF‐κB‐p65 subunit and determination of the cellular levels of I‐κB, the inhibitor of NF‐κB, revealed that SAC inhibited TNF‐α‐induced NF‐κB activation, and PD98059 treatment reversed this effect. These results collectively suggest that SAC inhibits TNF‐α‐induced inflammation in HaCaT cells via a combined effect entailing the inhibition of the p38 and the JNK pathways and NF‐κB pathway via the sustained activation of ERK.     

IL‐17F regulates psoriasis‐associated genes through IκBζ

Psoriasis is a common chronic inflammatory and immune‐mediated skin disease. Antagonists of TNF‐α and, recently, IL‐17 have proven to be highly effective in the treatment for psoriasis; however, the molecular mechanisms involved in the pathogenesis of psoriasis are poorly understood. Recently, we presented evidence that IκBζ is a key regulator in the development of psoriasis through its role in mediating IL‐17A‐driven effects. Like IL‐17A, IL‐17F is produced by a variety of immune cells, and the expression of IL‐17F is increased in psoriatic skin. The purpose of this study was to characterize the role of IL‐17F in the regulation of IκBζ expression and to investigate whether IL‐17F regulates psoriasis‐associated genes in human keratinocytes through IκBζ. Here, we demonstrate that IL‐17F stimulation induces IκBζ expression at both the mRNA and the protein levels in normal human keratinocytes. Moreover, silencing IκBζ by siRNA revealed that IκBζ is a key regulator of specific IL‐17F‐inducible psoriasis‐associated genes and proteins, including DEFB4/hBD2, S100A7, CCL20, IL‐8 and CHI3L1. In addition, IL‐17F‐induced IκBζ expression is mediated by a mechanism involving the p38 MAPK and NF‐κB signalling pathways, as shown by the clear reduction in IL‐17F‐mediated expression of IκBζ during chemical inhibition of these two signalling pathways. In summary, we present IκBζ as a novel key regulator of IL‐17F‐driven effects in psoriasis. Thus, antagonists to IκBζ could potentially provide a more targeted approach for treating psoriasis as well as for treating the other inflammatory and immune‐mediated diseases for which IL‐17‐targeting drugs have recently been approved.     

Treatment of refractory bullous pemphigoid with IFN‐α‐2b: A case report

We reported a patient with refractory bullous pemphigoid (BP), who had a higher level of eosinophils and serum IgE. The case showed less response to various therapies. Edematous erythema and new blisters appeared constantly. Considering IFN‐α‐2b treatment could significantly decrease blood eosinophils, we therefore expected that IFN‐α‐2b could be effective in the treatment of BP. After treated with IFN‐α‐2b, the patient's good response to the treatment suggested our hypothesis.     

Expressions of peroxisome proliferator‐activated receptors (PPARs) are directly influenced by permeability barrier abrogation and inflammatory cytokines and depressed PPARα modulates expressions of chemokines and epidermal differentiation‐related molecules in keratinocytes

Previous studies have demonstrated that the activation of peroxisome proliferator‐activated receptors (PPARs) not only has positive effects on permeability barrier homoeostasis but also has anti‐inflammatory effects by an as yet unknown mechanism. Reduced expression of PPARα in lesion of human atopic dermatitis (AD) and in epidermis of murine AD‐like dermatitis has been demonstrated. This study revealed that expression of PPARα alone among PPARs (α, β/δ and γ) was suppressed by both permeability barrier abrogation and additional existence of Th2 cytokine in cultured normal human keratinocytes. In addition, expressions of transglutaminase 1 and loricrin and those of thymus and activation‐related chemokine and regulated on activation normal T‐cell expressed in cultured human keratinocytes were reduced and enhanced, respectively, by transfection with siRNA for PPARα. In conclusion, depressed PPARα in keratinocytes might be involved in a relationship between permeability barrier abrogation and allergic inflammation and could be a therapeutic target which accounts for both the aspects in AD.