Characterization of spontaneous dermatitis in beige rats with IgE hyperproduction

BACKGROUND: Atopic dermatitis (AD) is a common skin disease characterized by chronic recurrent eczematous lesions, but its exact etiology and mechanism are unclear. We found that beige rats (DAbg/bg), a mutant model of Chediak-Higashi syndrome, develop skin lesions characterized by pruritus, excoriation, erosion and alopecia. We describe the beige rat and examine its possible usefulness as an AD model. METHODS: Beige rats of 4, 8, 13, 16, 26 and 52 weeks were used. Histological analysis of the skin was performed. Plasma IgE and cytokines were measured. Th1 and Th2 cytokines and RANTES mRNA expression of skin and lymph nodes were evaluated. Passive cutaneous anaphylaxis (PCA) reactions were examined, and maximization tests were conducted. RESULTS: Skin lesions begin to develop with increases in serum IgE levels and the expression of IL-4 mRNA in the lymph node and skin. Histologically, skin lesions are characterized by acanthosis, ulceration and inflammatory cell infiltration in the dermis. Inflammatory cells consist of CD3+, CD4+, ED1+, ED2+ and I-A+ mononuclear cells, eosinophils, degranulated mast cells and neutrophils accompanying interleukin (IL)-4, interferon (IFN)-gamma and RANTES mRNA expressions of the skin. Inflammatory cells are reduced during chronification with decreased expressions of IL-4, IFN-gamma and RANTES mRNA. In addition, the rats show a high sensitivity to PCA reactions and maximization tests. CONCLUSIONS: Our results show that some of the skin lesions of beige rats are morphologically similar to human AD, being characterized by inflammatory cell composition in the acute phase, and increased IgE and RANTES levels. However, the inflammatory process and cytokine expression pattern are different from those in human AD.     

Cutaneous CD30+ cells in children with atopic dermatitis

BACKGROUND: CD30 expression can be considered a marker of Th2 cells. We investigated the presence of CD30+ cells in the lesional skin of children with atopic dermatitis (AD). We also analyzed the possible relationship between CD30+ cells and serum soluble CD 30 (sCD30) levels, and IgE, soluble interleukin-2 (IL-2) receptor (sIL-2R) or soluble CD23 (sCD23) levels in the blood, and clinical score. METHODS: Ten eczematous children (4 males, 6 females; median age: 4 years and 5 months; range: 11 months to 14 years), 9 sex- and age-matched control children and an adult control group were studied. A clinical score (SCORAD index), was given to eczematous lesions. Blood was taken for the determination of IgE, sCD30, sIL-2R and sCD23 levels. Punch biopsies of lesional skin were stained with hematoxylin and eosin or incubated with anti-CD30 monoclonal antibodies. Skin prick tests (SPTs) were also performed. RESULTS: In the biopsy specimens, CD30 expression was observed in high proportions of infiltrating cells. In children with AD, total serum IgE, sCD30, sIL-2R, sCD23 and eosinophils were significantly elevated compared to controls. CD30+ cells were not associated with serum IgE, sCD30, sIL-2R, sCD23, or SPT results, score of inflammatory cells in lesional skin or clinical score. Children with AD who had high total IgE and specific IgE antibodies did not differ from those with normal total IgE and negative specific IgE in respect of age, clinical score, number of CD30+ cells, sCD30, sIL-2R and sCD23 levels, score of inflammatory cells in skin or clinical score. CONCLUSION: Our results showed remarkable numbers of CD30+ cells in the lesional skin and high sCD30 in the serum of children with AD. CD30+ cells did not correlate with systemic markers of IgE reaction.     

Dendritic cells in atopic dermatitis: expression of FcepsilonRI on two distinct inflammation-associated subsets

BACKGROUND: Dendritic cells (DCs) represent a major portion within the infiltrate of atopic dermatitis (AD) lesions. As antigen-presenting cells they have the ability to regulate both the quantity and quality of T-cell responses and, thus, are likely to play a key role in the pathogenesis of T-cell-dominated skin diseases such as AD. Thus we sought to identify the DC repertoire occurring in AD patients. METHODS: For this purpose, we phenotypically analyzed various defined DC subsets of AD patients and healthy controls in skin biopsies and peripheral blood by immunofluorescence staining. RESULTS: In AD lesions, two inflammation-associated DC subsets with varying expression of costimulatory molecules occurred besides epidermal Langerhans cells (LCs) and dermal myeloid DCs (dmDCs) indigenously residing in normal skin: (1) CD1a+/CD1c+/FcepsilonRI+/IgE+/CD207- myeloid DCs (mDCs) in the epidermis and dermis and (2) CD123+/BDCA-2+/CD45RA+/CD68+ plasmacytoid DCs (pDCs) in the dermis. In the peripheral blood of the patients, these cells exhibited an immature phenotype. Interestingly, we found FcepsilonRI and cell-bound IgE to be expressed not only on myeloid, but also on plasmacytoid DCs from both the skin and peripheral blood of AD patients. CONCLUSIONS: It is tempting to speculate that the disease-regulating role of inflammatory DCs in AD is influenced by both FcepsilonRI occupancy and their degree of maturity.     

Evidence for a role of Langerhans cell-derived IL-16 in atopic dermatitis

BACKGROUND: The factors controlling infiltration of inflammatory cells into atopic dermatitis (AD) lesions remain to be fully explored. Recently, epidermal cells in lesional AD were reported to contain increased messenger (m)RNA levels of IL-16, a cytokine that induces chemotactic responses in CD4(+)T cells, monocytes, and eosinophils. OBJECTIVES: We sought to determine the expression of IL-16 in epidermal cells in normal skin and skin from AD lesions and to investigate whether Langerhans cell (LC)-derived IL-16 may contribute to the initiation of atopic eczema. METHODS: The cutaneous expression of IL-16 was investigated by in situ hybridization and immunohistochemistry. Expression of IL-16 was also investigated in freshly isolated LCs and in keratinocytes by intracellular cytokine staining, quantitative real-time RT-PCR, and ELISA. RESULTS: Low levels of IL-16 mRNA, but no stored IL-16 protein, were detected in keratinocytes and LCs isolated from normal skin. Synthesis, storage, and secretion of IL-16 could be induced in LCs, but not keratinocytes, by activation with phorbol ester and ionomycin. In normal skin (n = 10) neither keratinocytes nor LCs expressed IL-16. In contrast, IL-16 was contained in approximately 40% of CD1a(+)LCs in patients with active AD (n = 16). IL-16 expression in LCs in patients with AD correlated with the number of infiltrating CD4(+)cells (r =.72, P =.0017) and was completely downregulated parallel to the clinical response of AD lesions to topical treatment with FK506. CONCLUSION: LC-derived IL-16 may participate in the recruitment and activation of inflammatory cells in AD.     

Epicutaneous sensitization with superantigen induces allergic skin inflammation

BACKGROUND: Atopic dermatitis (AD) is characterized by skin infiltration with eosinophils and lymphocytes and expression of Th2 cytokines in acute skin lesions. The skin of patients with AD is frequently colonized with enterotoxin-secreting strains of Staphylococcus aureus. Staphylococcal enterotoxins have been implicated in the exacerbations of the inflammatory skin lesions in patients with AD. OBJECTIVE: We sought to determine whether epicutaneous (EC) sensitization of mice with staphylococcal enterotoxin B (SEB) results in allergic skin inflammation. METHODS: BALB/c mice were EC-sensitized with SEB. Their skin was examined for allergic inflammation and cytokine expression, and their splenocytes were examined for cytokine secretion in response to SEB. RESULTS: EC sensitization with SEB elicited a local, cutaneous, inflammatory response characterized by dermal infiltration with eosinophils and mononuclear cells and increased mRNA expression of the Th2 cytokine IL-4 but not of the Th1 cytokine IFN-gamma. EC-sensitized mice mounted a systemic Th2 response to SEB evidenced by elevated total and SEB-specific IgG1 and IgE. Although EC sensitization with SEB resulted in selective depletion of SEB-specific T-cell receptor Vbeta8+ cells from the spleen and sensitized skin, splenocytes from SEB-sensitized mice secreted relatively more IL-4 and less IFN-gamma than did saline-sensitized controls, consistent with Th2 skewing of the systemic immune response to the superantigen. CONCLUSION: These results suggest that EC exposure to superantigens skews the immune response toward Th2 cells, leading to allergic skin inflammation and increased IgE synthesis that are characteristic of AD.     

In vivo relevance of CD30 in atopic dermatitis

CD30 expression was evaluated by immunohistochemistry in lesional skin biopsies of eight patients with active atopic dermatitis (AD) and three patients with allergic contact (nickel-induced) dermatitis (ACD). CD30 expression was also assessed in a large panel of CD4 + and CDS + T-cell clones generated from the skin biopsies of four patients with AD. Finally, the levels of soluble CD30 (sCD30) were measured in the serum of 41 patients with AD, 19 patients with ACD, and 60 healthy controls. In all specimens of lesional AD skin, where the great majority of infiltrating cells were CD4+ T cells, remarkable numbers of cells were CD30+, whereas virtually no CD30 + cells were found in the skin of patients with ACD. In CD4+ T-cell clones generated from the lesional AD skin, most of which produced both interleukin (IL)-4 and interferon-gamma (IFN-γ) (Th0–like cells) or IL-4 and 1L-5, but not IFN-γ (Th2–like cells), CD30 expression directly correlated with the ability to produce IL-4 and IL-5, but was inversely related to IFN-γ production. High levels of sCD30 (correlated with disease activity: r = 0.618) were detected in the serum of most AD patients, whereas there was no increase of sCD30 levels in the serum of patients with ACD. These data support the view that Th0/Th2–type responses predominate in the skin of patients with AD and suggest that the presence of CD30 + T cells in tissues and/or increased levels of sCD30 in biologic fluids are indicative of Th2–dominated responses.     

A Role of Staphyococcus aureus, Interleukin-18, Nerve Growth Factor and Semaphorin 3A, an Axon Guidance Molecule, in Pathogenesis and Treatment of Atopic Dermatitis

Staphylococcus aureus (SA) is usually present not only in the skin lesions of atopic dermatitis (AD) but also in the atopic dry skin. SA discharges various toxins and enzymes that injure the skin, results in activation of epidermal keratinocytes, which produce and release IL-18. IL-18 that induces the super Th1 cells secreting IFN-γ and IL-13 is supposed to be involved in development of AD and its pathogenesis. Indeed, the number of SA colonies on the skin surface and the serum IL-18 levels in patients with AD significantly correlated with the skin scores of AD lesions. Also, there is strong positive correlation between the skin scores and serum IL-18 levels in DS-Nh mice (P<0.0001, r=0.64), which develop considerable AD-like legions when they are housed under conventional conditions, but develop skin legions with less severity and less frequency under specific pathogens free (SPF) conditions. Therefore, they are well-known as model mice of AD, in which SA is presumed to be critical factor for the development of AD lesions. Also, theses DS-Nh mice pretreated with Cy developed more remarkable AD-like lesions in comparison with non-treated ones. The levels of INF-r and IL-13 in the supernatants of the lymph node cell cultures stimulated with staphylococcal enterotoxin B (SEB) or ConA were increased in the Cy-treated mice, although the serum levels of total IgE were not. In this experiment, we revealed that Cy-treated mice, to which CD25 +CD4 + reguratory T cells taken from non-treated ones had been transferred, developed the AD-like legions with less severity and less number of SA colonies on the skin surface. Therefore, it is presumed that CD25 +CD4 + reguratory T cells might be involved in the suppression of super Th1 cells which are induced by IL-18 and are involved in the development of AD-like lesions rather than IgE production. The efficient induction of CD25 +CD4 + reguratory T cells is expected for the new type of treatment of AD. We also found that farnesol (F) and xylitol (X) synergistically inhibited biofilm formation by SA, and indeed the ratio of SA in total bacteria at sites to which the FX cream containing F and X had been applied was significantly decreased 1 week later, accompanied with improvement of AD, when compared with that before application and at placebo sites. Therefore, the FX cream is a useful skin-care agent for atopic dry skin colonized by SA. The nerve growth factor (NGF) in the horny layer (the horn NGF) of skin lesions on the cubital fossa was collected by tape stripping and measured using ELISA in AD patients before and after 2 and 4 weeks treatments. Simultaneously, the itch and eruptions on the whole body and on the lesions, in which the horn NGF was measured, were recorded, and also the peripheral blood eosinophil count, serum LDH level and serum total IgE level were examined. The level of NGF was significantly higher in AD patients than in healthy controls, correlated with the severity of itch, erythema, scale/xerosis, the eosinophil count and LDH level, and also significantly decreased after treatments with olopatadine and/or steroid ointment for 2 and 4 weeks. Therefore, the measurement of the NGF by this harmless method seems to be useful to assess the severity of AD and the therapeutic effects on AD. In AD patients, C-fiber in the epidermis increase and sprout, inducing hypersensitivity, which is considered to aggravate the disease. Semaphorin 3A (Sema3A), an axon guidance molecule, is a potent inhibitor of neurite outgrowth of sensory neurons. We administered recombinant Sema3A intracutaneously into the skin lesions of NC/Nga mice, an animal model of AD, and investigated the effect of Sema3A on the skin lesions and their itch. Sema3A dose-dependently improved skin lesions and attenuated the scratching behavior in NC/Nga mice. Histological examinations revealed a decrease in the epidermal thickness, the density of invasive nerve fibers in the epidermis, inflammatory infiltrate including mast cells and CD4 +T cells, and the production of IL-4 in the Sema3A-treated lesions. Because the interruption of the itch-scratch cycle likely contributes to the improvement of the AD-like lesions, Sema3A is expected to become a promising treatment of patients with refractory AD.     

The impact of langerin (CD207)+ dendritic cells and FOXP3+ Treg cells in the small bowel mucosa of children with celiac disease and atopic dermatitis in comparison to children with functional gastrointestinal disorders

In the present study we aimed to evaluate the impact of langerin (CD207)+ dendritic cells (DCs) and FOXP3+ Treg cells in the intestinal mucosa of children with celiac disease (CD) and atopic dermatitis (AD) in comparison to children with functional gastrointestinal disorders (FGD). Seventy‐five children (37 male, mean age 8.4 ± 4.8 years), who randomly underwent small bowel biopsy, were studied. The CD was diagnosed in 14 children, including five persons with concomitant AD (all positive for anti‐tissue transglutaminase IgA antibodies and with small bowel atrophy). Normal small bowel mucosa was found in eight patients with AD and in 53 patients with FGD. The sera of all patients were tested for total and specific IgE antibodies to food allergen panels. Staining for CD11c+, langerin (CD207+) DCs, CD4+, and FOXP3+ Treg cells was performed on paraffin‐embedded sections of bioptates using immunohistochemistry. The density of CD11c+ DCs, CD4+, and FOXP3+ Treg cells was higher in the CD patients compared to the AD and FGD patients (p = 0.02; p = 0.001). In AD, significantly higher density of CD11c+ DCs was detected in patients positive for specific IgE to food allergen panels (p = 0.02). The FGD patients with elevated total IgE had increased density of langerin (CD207)+ DCs compared to the patients with normal total IgE levels (p = 0.01). The increased density of FOXP3+ Treg cells, CD4+, cells and CD11c+ DCs was associated with CD but not with AD. The elevated level of total IgE or specific IgE to food allergens was associated with more pronounced expression of DCs, indicating a possible link between the presence of these cells in small bowel mucosa with elevated level of serum IgE.     

Different cytokine production and activation marker profiles in circulating cutaneous-lymphocyte-associated antigen+ T cells from patients with acute or chronic atopic dermatitis

BACKGROUND: Atopic dermatitis (AD) is an inflammatory skin disease whose lesions can have two stages: acute and chronic. In skin biopsies a biphasic pattern of cytokine expression has been shown, Th2 in acute lesions and Th1 in chronic AD lesions. OBJECTIVE: We investigated the expression of an activation marker and a homing receptor, as well as cytokine production, in different peripheral blood T cell subpopulations from AD patients with chronic (Group A) and acute lesions (Group B) and controls. METHODS: We evaluated 26 adult AD patients (12 Group A, 14 Group B) and 14 non-atopic controls. IgE was measured by immunoassay. CD4, CD8, cutaneous-lymphocyte-associated antigen (CLA) and human leucocyte antigen (HLA)-DR expression, and cytokine production (IL-2, IL-13, IFN-gamma, TNF-alpha, IL-10, IL-4) were analysed in mononuclear cells by flow cytometry. RESULTS: In Group B there was a significant increase in eosinophil levels and a non-significant increase in IgE. In Group A we found an increase in CLA(+)CD4(+) cells (8.19+/-1.84) compared with controls (4.83+/-0.53) (P<0.05) and CD4(+)HLA-DR(+) cells in the CLA(+) subpopulation (45.54+/-15.40) compared with controls (30.49+/-6.07) (P<0.05). In the CLA(+)CD4(+) subpopulation, there was a significant increase in IL-4, IL-13 and TNF-alpha production in Group B (12.46+/-7.7, 11.26+/-5.97, 43.92+/-15.55) compared with controls (5.34+/-3.50, 4.54+/-1.78, 19.29+/-9.97) with no differences in Group A. CONCLUSION: Greater immunological differences were detected in peripheral blood from patients with acute compared with chronic lesions, especially in the circulating T cell-subset with skin tropism that preferentially responded to cutaneous allergens. This is the first demonstration of phenotypic changes in circulating CLA(+) T cells between AD patients with acute and chronic lesions.     

Tacrolimus ointment causes inflammatory dendritic epidermal cell depletion but no Langerhans cell apoptosis in patients with atopic dermatitis

BACKGROUND: The topical immunomodulators tacrolimus and pimecrolimus are novel therapeutic options for atopic dermatitis (AD). The inhibition of nuclear factor of activated T cell-dependent proinflammatory cytokine production in cutaneous lymphocytes is an established effect of topical immunomodulators, which additionally influence mast cells, eosinophils, and dendritic cells (DCs). The latter include a reduced expression of the high-affinity IgE receptor FcepsilonRI, a reduced stimulatory capacity of lesional DCs, and a selective depletion of the inflammatory dendritic epidermal cells (IDECs) but not of Langerhans cells (LCs) from the lesional skin. OBJECTIVE: Because induction of apoptosis in lymphocytes is a reported tacrolimus effect, we asked whether tacrolimus ointment induces apoptosis of LCs or IDECs in AD lesions. METHODS: Epidermal single-cell suspensions were prepared from AD lesions of 9 tacrolimus-treated and 5 hydrocortisone butyrate-treated patients with AD before and after 1 week of treatment. Cell numbers, apoptosis rate, and immunophenotype were assessed by using the standardized FACS technique with terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling, Annexin V, and 3-color immunophenotyping. Freshly isolated LCs and monocyte-derived DCs served as in vitro controls. RESULTS: Tacrolimus and steroid ointment induced a selective depletion of IDECs from the epidermis and reduced the expression of the costimulatory molecules CD80 and CD86. Tacrolimus ointment did not increase the rate of apoptotic DCs, whereas steroid ointment did so. The isolation-induced high apoptosis rate of freshly isolated LCs was unaffected by both drugs. CONCLUSION: Tacrolimus ointment selectively depletes IDECs and alters the immunophenotype of epidermal DCs in AD lesions, but there is no evidence for tacrolimus-induced DC apoptosis in this phenomenon.     

Application of concentrated deep sea water inhibits the development of atopic dermatitis-like skin lesions in NC/Nga mice

ABSTRACT: BACKGROUND: Mineral water from deep-sea bedrock, formed over thousands of years, is rich in minerals such as Ca, Mg, Na, K, Fe and others. Our present study was to investigate the preventive effects of natural deep-sea water on developing atopic dermatitis (AD). METHODS: We elicited AD by application of DNCB (2,4-dinitro-chlorobezene) in Nc/Nga mouse dorsal skin. Deep Sea water (DSW) was filtered and concentrated by a nanofiltration process and reverse osmosis. We applied concentrated DSW (CDSW) to lesions five times per week for six weeks, followed by evaluation. 1% pimecrolimus ointment was used as positive control. The severity of skin lesions was assessed macroscopically and histologically. Levels of inflammatory mediators and cytokines in the serum were detected by Enzyme-linked immunosorbent assay (ELISA) and the levels of CD4+ and CD8+ spleen lymphocytes were determined by flow cytometry analysis. RESULTS: DNCB-treated mice showed atopic dermatitis-like skin lesions. Treatment of mice with CDSW reduced the severity of symptoms in the skin lesions, including edema, erythema, dryness, itching, and transepidermal water loss (TEWL). Histological analyses demonstrated that epidermal thickness and infiltration of inflammatory cells were decreased after CDSW treatment. Given these interesting observations, we further evaluated the effect of CDSW on immune responses in this AD model. Treatment AD mice with CDSW inhibited up-regulation of IgE, histamine, and pro-inflammatory cytokines in the serum. Also, the CD4+/CD8+ ratio in spleen lymphocyte was down-regulated after treatment with CDSW. Finally, cytokines, especially IL-4 and IL-10 which are important for Th2 cell development, were reduced. CONCLUSIONS: Our data suggests that topical application of CDSW could be useful in preventing the development of atopic dermatitis.     

T cells expressing the Vgamma1 T-cell receptor enhance virus-neutralizing antibody response during coxsackievirus B3 infection of BALB/c mice: differences in male and female mice

Coxsackievirus B3 infection causes severe cardiac inflammation in male but not female mice. CD3+ T cells and T cells expressing the Vgamma4 T cell receptor (TCR) predominate in the cardiac inflammatory cell infiltrate in infected male BALB/c mice. Infected females have mostly CD19+ (B lymphocyte) and Vgamma1+ cells. No significant differences in CD11b+ (monocyte) cells were observed between the sexes. Infected males showed a predominant CD4+Th1 (IFNgamma+) response, whereas females showed a predominant CD4+Th2 response. The importance of IFNgamma for myocarditis susceptibility and IL-4 for protection was confirmed using IFN-gamma-/- and IL-4-/- mice. Antibody depletion of Vgamma1+ cells augmented myocarditis susceptibility, whereas antibody depletion of Vgamma4+ cells was protective. Cardiac virus titers inversely correlated with virus neutralizing antibodies and showed that Vgamma1+ cells are important for virus neutralizing antibody response. IFNgamma affected the Vgamma4+ cell response in the heart, as IFNgamma-/- mice had few Vgamma4+ cells; but exogenous administration of recombinant IFNgamma to IFNgamma-/- mice restored myocarditis susceptibility, Th1 bias, and Vgamma4+ cell infiltration of the myocardium. These results demonstrate that two gammadelta+ T cell populations, Vgamma1+ and Vgamma4+, have different functions during myocarditis, in that Vgamma1+ cells promote humoral immunity and protection whereas Vgamma4+ cells are pathogenic.     

Sulfuretin alleviates atopic dermatitis-like symptoms in mice via suppressing Th2 cell activity

Atopic dermatitis (AD) is a chronic skin inflammatory disease characterized by uncontrolled Th2 cells response to environmental allergens. Long-term topical application of corticosteroids for treating AD may induce severe side effects. Sulfuretin is a major flavonoid found in Rhus verniciflua and carries antioxidant and anti-inflammatory properties. Its therapeutic effect on AD has not been characterized. We first studied the cytotoxic and regulatory effects of sulfuretin on differentiated Th2 cells. Next, we evaluated therapeutic effect of sulfuretin on AD-like damages caused by 2,4-dinitrochlorobenzene (DNCB) in a mouse model. Serum IgE level, overall symptomatic score, and cytokine accumulation at the lesions were measured. Lastly, we investigated the regulatory mechanism of sulfuretin on GATA3 pathway in primary mouse CD4⁺ cells. Study on in vitro differentiated Th2 cells showed sulfuretin inhibited IL4 production in dose-dependent manner without any cytotoxicity. In vivo study showed 10 μM sulfuretin alleviated the AD symptoms including skin lesion severity, scratching incidence, IgE serum level, and proinflammatory cytokine accumulation at local skin lesion site. Mechanistic study suggested sulfuretin attenuated Th2 cytokine production by suppressing GATA3 expression. Our results demonstrate that sulfuretin could be used as therapeutic application for treating AD.     

The study of immunological markers in patients with "intrinsic" type atopic dermatitis]

Atopic dermatitis (AD) is a common inflammatory skin disease characterized by several clinical, immunological and biochemical alterations. Comparing the patients with the 'extrinsic' and 'intrinsic' types of AD, we investigated the role of immunological mechanisms in the pathogenesis of AD. To confirm it, we calculated serum markers of T lymphocyte activation: soluble interleukin-2 receptor (sIL-2R), interleukin-4 (IL-4), interleukin-10 (IL-10) and interferon-gamma (IFN-gamma). The soluble CD14 (sCD14) and tumor necrosis factor-alpha (TNF-alpha) in serum were measured as monocyte/macrophage activation markers. We examined 29 patients with the 'extrinsic' type AD (serum IgE > 10000 IU/ml: High-AD), 23 patients with the 'intrinsic' type AD (serum IgE < 37 IU/ml: Low-AD) and 11 healthy controls. Serum sIL-2R levels were increased in High-AD and Low-AD compared with the controls. They were also significantly increased in High-AD compared with Low-AD. Serum sCD14 levels were increased in High-AD compared with Low-AD and the controls. Severity index of AD were correlated with serum sIL-2R levels but not with sCD14 levels in sera. In conclusion, IgE may not relate with the pathogenesis of atopic dermatitis. Serum sIL-2R levels may be increased according to inflammatory skin lesions and it may be exaggerated with the immunological activation in the patients with the 'extrinsic' type AD.     

House dust mite-specific T cells in the skin of subjects with atopic dermatitis: frequency and lymphokine profile in the allergen patch test.

The mechanism underlying positive patch tests with house dust mite-allergen, Dermatophagoides pteronyssinus (Der p), in patients with atopic dermatitis was investigated by isolating T cells from the test sites of two patients. Eighty-five T cell clones (TCC) were established from the epidermis and dermis of lesional skin by the limiting-dilution method with Der p and interleukin (IL)-2. With restimulation assays, 29 of 60 TCCs tested demonstrated specific proliferation; 85% were of the CD3+, CD2+, and CD4+ phenotype. Der p-specific T cells constituted 0.4% to 2.7% of lesional T cells, and they were more frequent in the skin than in the blood of the patients by one order of magnitude. The mitogen-stimulated lymphokine profile of 55 TCCs was assessed; 42% (11/26) of the allergen-specific TCCs secreted IL-4 but almost no interferon-gamma, as described for the Th2 subset of the mouse. Also, six selected TCCs supported IgE secretion by autologous lymphocytes. Only three of 26 allergen-specific, skin-derived TCCs demonstrated a Th1-like lymphokine profile. These results support the specific nature of Der p-induced patch test lesions in patients with atopic dermatitis, and the results demonstrate also that a considerable proportion of lesional T cells are allergen-specific, IL-4-producing T cells that are capable of enhancing IgE production.     

Lipoteichoic acid from Staphylococcus aureus enhances allergen-specific immunoglobulin E production in mice

BACKGROUND: Our previous study demonstrated that lipoteichoic acid (LTA) from Staphylococcus aureus induced T helper type 2 (Th2)-prone dermatitis resembling that seen in atopic dermatitis (AD) patients in mice sensitized percutaneously with an allergen. However, the effects of LTA on allergen-specific IgE production in such sensitized mice have not been elucidated. OBJECTIVE: The purpose of this study was to determine the effects of LTA from S. aureus on allergen-specific IgE production in mice sensitized percutaneously with a house dust mite antigen (MA). METHODS: Mice were sensitized with a single topical application of MA and/or LTA to barrier-disrupted abdominal skin. One to 5 weeks later, MA-specific IgE antibodies in sera from sensitized mice were detected by an enzyme-linked immunosorbent assay (ELISA). Expression of B7.1 (CD80), B7.2 (CD86) and CD40L molecules by CD40-positive (CD40+) and CD4-positive (CD4+) cells in the lymph nodes of sensitized mice were analysed by flow-cytometry (FACS). RESULTS: Simultaneous sensitization with MA and LTA increased IgE production 3 weeks later, significantly more than sensitization with MA alone. FACS analysis of CD40+ cells in the lymph nodes from sensitized mice showed that simultaneous sensitization with MA and LTA did not enhance CD80- or CD86-expression by antigen-presenting cells such as B lymphocytes and dendritic cells more than sensitization with MA alone. However, analysis of CD4+ cells in the lymph nodes showed that simultaneous sensitization with MA and LTA increased the number of CD40L-expressing Th cells more than sensitization with MA alone. CONCLUSION: These results suggest that LTA enhances allergen-specific IgE production by a mechanism associated with up-regulation of CD40L-expressing Th cells and this might explain the role of skin colonization with S. aureus in AD patients.     

The Role of Th17/Tc17 Peripheral Blood T cells in Psoriasis and Their Positive Therapeutic Response

It is known that NB‐UVB therapy can suppress a broad range of immune cells, but the additional effect of bathing in geothermal seawater still remains unclear. To study the influence of treatment on the expression of circulating immune cells contributing to the pathogenesis of psoriasis, six patients with psoriasis were treated with bathing in geothermal seawater two times daily combined with NB‐UVB five times/week for 2 weeks and six patients were treated with NB‐UVB therapy three times/week for 8 weeks. Disease severity (Psoriasis Area and Severity Index, PASI), chemokines, inflammatory cytokines, T cells and Toll‐like receptors in the blood and skin samples were evaluated on enrolment (W0) and at 1 (W1), 3 (W3) and 8 (W8) weeks. Compared with healthy controls, psoriasis patients with active disease had significantly higher proportion of peripheral CLA+ T cells expressing CCR10 and CD103 and T cells with both Th1/Tc1 (CD4+/CD8+ IFN‐γ+ or TNF‐α+ cells) and Th17/Tc17 (CD4+CD45R0+IL‐23R+, CD4+/CD8+ IL‐17A+ or IL‐22+ cells) phenotypes. Both treatments gave a significant clinical effect; however, bathing in geothermal seawater combined with NB‐UVB therapy was more effective than NB‐UVB therapy alone. This clinical improvement was reflected by a reduction in circulating CLA+ peripheral blood T cells and by a decreased Th1/Th17 and Tc1/Tc17 inflammatory response. These findings suggest that the inflammatory response in psoriasis is predominantly driven by both CD4+ and CD8+ skin‐homing tissue retaining T cells of the Th17/Tc17 lineages.     

Atopy patch test reactions show a rapid influx of inflammatory dendritic epidermal cells in patients with extrinsic atopic dermatitis and patients with intrinsic atopic dermatitis

BACKGROUND: Normal human skin harbors a single epidermal dendritic cell (DC) population, the CD1a(+++)CD11b(-) Langerhans cells. In many chronic inflammatory skin diseases, the epidermal DC pool bears a second population, the CD1a(+)CD11b(+++) inflammatory dendritic epidermal cells (IDECs). Immunophenotypic, ultrastructural, and functional aspects of IDECs have been investigated in chronic untreated skin lesions of intrinsic and extrinsic atopic dermatitis (AD), contact dermatitis (CD), and psoriasis, but little is known about freshly induced early skin lesions. OBJECTIVE: We sought to characterize enumerative and immunophenotypic changes in the epidermal DC pool during the development of eczematous skin lesions. METHODS: The atopy patch test with aeroallergens and food-protein allergens and a conventional patch test with standard-series haptens were performed as models for early skin lesions of extrinsic and intrinsic AD and CD, respectively. After 72 hours, epidermal cell suspensions were prepared, analyzed in a standardized flow cytometric technique, and compared with the results obtained from chronic lesions. RESULTS: The migration of IDECs into the epidermis occurs within 72 hours and is thus an early event. It continues in chronic AD, but not in chronic CD, lesions. The specific upregulation of FcepsilonRI, especially on IDECs, occurs later during formation of extrinsic but not intrinsic AD lesions. LCs were negative for Cd36 in patch test lesions, whereas in chronic skin lesions, LCs expressed Cd36. CONCLUSION: The DC alteration during skin lesion formation can be subdivided into early and late events, with the influx of IDECs as an early event and the alteration of the DC phenotype as a late event.     

CD30 expression on circulating memory CD4+ T cells as a Th2-dominated situation in patients with atopic dermatitis

Th2 clones have been reported to express CD30 preferentially, but whether T cells producing Th2-type cytokines may favor CD30 expression in the in vivo state remains unknown. We investigated the expression of CD30 on circulating T cells in atopic dermatitis (AD) as a Th2-dominated disorder. Peripheral blood mononuclear cells were prepared from 51 AD patients and 14 nonatopic controls, and their phenotypes were analyzed with flow cytometry. Cytokine production by stimulated CD4+ T cells was also assessed by the single-cell-staining method. Flow cytometric analysis clearly revealed that CD30+ T cells were identifiable in the blood of AD patients with greater frequency compared to controls. The important finding was that CD30 expression was restricted to a small but substantial population of memory (CD45RO+) CD4+ T cells, but not CD8+ ones. In AD patients, it was demonstrated that the percentages of CD30+ cells within CD45RO+ CD4+ T cells correlated well with the disease severity, serum IgE levels, peripheral eosinophil counts, and tendency toward Th2-dominant cytokine pattern as determined by the ratio of interleukin-4 to interferon-gamma production. This study suggests that CD30 expression in circulating T cells might serve as an in vivo marker for the Th2-dominated condition.     

Enhanced expression of B7.2 (CD86) by percutaneous sensitization with house dust mite antigen

House dust mite antigen is a well-known allergen in the pathogenesis of atopic dermatitis (AD), a chronic relapsing inflammatory skin disease. We evaluated the AD model mice sensitized with house dust mite antigen and observed a Th2-dominant immune response. In this experiment, BALB/c mice were sensitized percutaneously with house dust mite antigen three times with 7 days interval after skin barrier disruption. A remarkable infiltration of polymorphonuclear granulocytes and monocytes in the cutis was observed in mice treated with this antigen, high serum IgE levels and IL-4 mRNA expression in local lymph node cells was also observed. CD19(+) B cell numbers overturned to CD4(+) helper T cells. In these mice, there was significant increase of B7.2 (CD86) expression on CD19(+) B cells. These results indicate that house dust mite antigen sensitizes BALB/c mice and skews their Th1/Th2 balance toward Th2.