Sustaining the T-cell activity in xenografted psoriasis skin.

Xenografting of psoriasis skin onto immune deficient mice has been widely used to obtain proof-of-principle of new drug candidates. However, the lack of human T-cell activity in the grafts limits the use of the model. Here, we show that xenografting of lesional skin from psoriasis patients onto human IL-2 NOG mice results in increased numbers of human CD3+ cells in the grafts, axillary lymph nodes and blood from human IL-2 NOG mice compared to C.B-17 scid and NOG mice. In addition, disease relevant human cytokine levels were higher in graft lysates and serum from human IL-2 NOG mice. However, the epidermis was lacking and no efficacy of ustekinumab, a human anti-P40 antibody targeting both IL-12 and IL-23, was shown. Thus, despite the sustained T-cell activity, the model needs further investigations and validation to capture more aspects of psoriasis.

Occupation with grain crops is associated with lower type 1 diabetes incidence: Registry-based case-control study.

Intranasal administration of gliadin prevents autoimmune diabetes in non-obese diabetic mice. The current study was designed to investigate if bakers are intranasally exposed to gluten during work and whether occupation as baker is inversely associated with type 1 diabetes. Gliadin was measured in nasal swabs from eight bakers and butchers. The odds ratio of type 1 diabetes in selected profession groups was analysed in a registry-based case-control study with data from 1980 to 2010 derived from Statistics Denmark. The cohort included 1,210,017 Danish individuals, thereof 15,451 with type 1 diabetes (1.28%). Average nasal gliadin swab content after full working days was 6.3 µg (confidence interval (CI): 2.8 to 9.7) among bakers, while no nasal gliadin was detected among butchers. The odds ratio of type 1 diabetes was lower among bakers (OR = 0.57; CI: 0.52 to 0.62) and agriculture workers occupied with production of grains (OR = 0.65; CI: 0.56 to 0.75). Bakers had a lower odds ratio of type 1 diabetes, which potentially could be attributed to exposure of nasal mucosal gluten during work, as observed in this study. If other studies confirm the present observations, intranasal gliadin administration could possibly be an easy and safe approach for the prevention of type 1 diabetes in high-risk individuals or prediabetic subjects.

Sensitivity to oxazolone induced dermatitis is transferable with gut microbiota in mice.

Atopic Dermatitis (AD) has been associated with gut microbiota (GM) dysbiosis in humans, indicating a causative role of GM in AD etiology. Furthermore, the GM strongly correlates to essential disease parameters in the well-known oxazolone-induced mouse model of AD. Here, we demonstrate that it is possible to transfer both a high-responding and a low-responding AD phenotype with GM from conventional mice to germ-free mice. The mice inoculated with the high-responding GM had significantly higher clinical score, increased ear thickness, and increased levels of IL-1ß, TNFα, IL-4, IL-5, and IL-6 compared to the mice inoculated with the low-responding GM. The inter-individual variation was in general not affected by this increase in effect size. Germ-free mice induced with AD revealed a high disease response as well as high inter-individual variation indicating protective properties of certain microbial taxa in this model. This study underlines that the GM has a strong impact on AD in mouse models, and that the power of studies may be increased by the application of mice inoculated with a specific GM from high responders to increase the effect size.

CD1d knockout mice exhibit aggravated contact hypersensitivity responses due to reduced interleukin-10 production predominantly by regulatory B cells.

Conflicting observations have been reported concerning the role of CD1d-dependent natural killer T (NKT) cells in contact hypersensitivity (CHS), supporting either a disease-promoting or downregulatory function. We studied the role of NKT cells in CHS by comparing the immune response in CD1d knockout (CD1d KO) and wild-type (Wt) mice after contact allergen exposure. For induction of CHS, C57BL/6 CD1d KO mice (n = 6) and C57BL/6 Wt mice (n = 6) were sensitised with 1% (w/v) dinitrochlorobenzene (DNCB) or vehicle for three consecutive days and subsequently challenged with a single dose of 0.5% DNCB (w/v) on the ears fifteen days later. We demonstrate that CD1d KO mice, as compared with Wt littermates, have more pronounced infiltration of mononuclear cells in the skin (29.1% increase; P < 0.001), lower frequencies of interleukin-10(+) B cells (B(regs) ) in the spleen (53.2% decrease; P < 0.05) and peritoneal cavity (80.8% decrease; P < 0.05) and increased production of interferon-γ (3-fold; P < 0.05) after DNCB sensitisation and challenge, which suggests an important regulatory and protective role of CD1d-dependent NKT cells in CHS in our model, at least in part via regulation of IL-10 producing B(regs) .

Effect of dietary gluten on dendritic cells and innate immune subsets in BALB/c and NOD mice.

The innate immune system is known to play an important role in oral tolerance to dietary antigens. This is important in development of celiac disease (CD) but may also be important in type 1 diabetes (T1D), and could potentially explain the reduced incidence of T1D in mice receiving a gluten-free (GF) diet. The direct in vivo effect of gluten on innate cells, and particularly dendritic cells (DC) is not sufficiently clarified. Therefore, we wished to investigate the innate cell populations of spontaneous diabetic NOD mice and healthy BALB/c mice kept on a GF or a standard (STD) gluten containing diet. We studied, by flow cytometry and reverse transcription-quantitative polymerase chain reaction (qRT-PCR), if dietary gluten induces changes in the activation of DCs and distribution of selected innate cells in lymphoid, pancreatic and intestinal tissues in BALB/c and NOD mice. We found that a GF diet increased the percentage of macrophages in BALB/c spleen and of CD11c+ DCs in BALB/c and NOD spleen. Strictly gluten-free (SGF) diet increased the percentage of CD103+ DCs in BALB/c mice and decreased percentages of CD11b+ DCs in mesenteric and pancreatic lymph nodes in BALB/c mice. SGF diet in BALB/c mice also decreased DC expression of CD40, CCR7 and MHC-II in pancreatic lymph nodes. In conclusion, GF diet changes the composition of the innate immune system in BALB/c and NOD mice and increases expression of DC activation markers in NOD mice. These results contribute to the explanation of the low diabetes incidence in GF NOD mice. This mechanism may be important in development of type 1 diabetes, celiac disease and non-celiac gluten sensitivity.

Dietary gluten increases natural killer cell cytotoxicity and cytokine secretion.

Dietary gluten influences the development of type 1 diabetes in nonobese diabetic (NOD) mice and biobreeding rats, and has been shown to influence a wide range of immunological factors in the pancreas and gut. In the present study, the effects of gluten on NK cells were studied in vitro and in vivo. We demonstrated that gliadin increased direct cytotoxicity and IFN-γ secretion from murine splenocytes and NK cells toward the pancreatic beta-cell line MIN6 cells. Additionally, stimulation of MIN6 cells led to a significantly increased proportion of degranulating C57BL/6 CD107a(+) NK cells. Stimulation of C57BL/6 pancreatic islets with gliadin significantly increased secretion of IL-6 more than ninefold. In vivo, the gluten-containing diet led to a higher expression of NKG2D and CD71 on NKp46(+) cells in all lymphoid organs in BALB/c and NOD mice compared with the gluten-free diet. Collectively, our data suggest that dietary gluten increases murine NK-cell activity against pancreatic beta cells. This mechanism may contribute to development of type 1 diabetes and explain the higher disease incidence associated with gluten intake in NOD mice.

Dietary gluten and the development of type 1 diabetes.

Gluten proteins differ from other cereal proteins as they are partly resistant to enzymatic processing in the intestine, resulting in a continuous exposure of the proteins to the intestinal immune system. In addition to being a disease-initiating factor in coeliac disease (CD), gluten intake might affect type 1 diabetes development. Studies in animal models of type 1 diabetes have documented that the pathogenesis is influenced by diet. Thus, a gluten-free diet largely prevents diabetes in NOD mice while a cereal-based diet promotes diabetes development. In infants, amount, timing and mode of introduction have been shown to affect the diabetogenic potential of gluten, and some studies now suggest that a gluten-free diet may preserve beta cell function. Other studies have not found this effect. There is evidence that the intestinal immune system plays a primary role in the pathogenesis of type 1 diabetes, as diabetogenic T cells are initially primed in the gut, islet-infiltrating T cells express gut-associated homing receptors, and mesenteric lymphocytes transfer diabetes from NOD mice to NOD/severe combined immunodeficiency (SCID) mice. Thus, gluten may affect diabetes development by influencing proportional changes in immune cell populations or by modifying the cytokine/chemokine pattern towards an inflammatory profile. This supports an important role for gluten intake in the pathogenesis of type 1 diabetes and further studies should be initiated to clarify whether a gluten-free diet could prevent disease in susceptible individuals or be used with newly diagnosed patients to stop disease progression.

Systemic immunogenicity of para-Phenylenediamine and Diphenylcyclopropenone: two potent contact allergy-inducing haptens.

p-Phenylenediamine (PPD) and Diphenylcyclopropenone (DPCP) are two potent haptens. Both haptens are known to cause delayed-type hypersensitivity, involving a cytokine response and local infiltration of T-cell subpopulations, resulting in contact dermatitis. We investigated the systemic immune effects of PPD and DPCP, two relatively unexplored skin allergens. The dorsal sides of the ears of BALB/c mice were exposed to PPD or DPCP (0.1% w/v or 0.01% w/v), or vehicle alone. Mice were treated once daily for 3 days (induction period) and subsequently twice per week for 8 weeks. Local and systemic immune responses in the auricular and pancreatic lymph nodes, spleen, liver, serum, and ears were analyzed with cytokine profiling MSD, flow cytometry, and qPCR. Ear swelling increased significantly in mice treated with 1% PPD, 0.01% DPCP or 0.1% DPCP, compared with vehicle treatment, indicating that the mice were sensitized and that there was a local inflammation. Auricular lymph nodes, pancreatic lymph nodes, spleen, and liver showed changes in regulatory T-cell, B-cell, and NKT-cell frequencies, and increased activation of CD8(+) T cells and B cells. Intracellular cytokine profiling revealed an increase in the IFN-γ- and IL-4-positive NKT cells present in the liver following treatment with both haptens. Moreover, we saw a tendency toward a systemic increase in IL-17A. We observed systemic immunological effects of PPD and DPCP. Furthermore, concentrations too low to increase ear thickness and cause clinical symptoms may still prime the immune system. These systemic immunological effects may potentially predispose individuals to certain diseases.

A possible association between a dysfunctional skin barrier (filaggrin null-mutation status) and diabetes: a cross-sectional study.

Background Filaggrin proteins are located in the skin and prevent epidermal water loss and impede the entry of micro-organisms, allergens and chemicals. Filaggrin null mutations are strongly associated with ichthyosis vulgaris and atopic dermatitis. Objective The authors aimed to investigate the association between filaggrin null mutations, atopic dermatitis and diabetes. Design A random sample of 3335 adults from the general population in Denmark was filaggrin-genotyped for R501X and 2282del4 null-mutations and questioned about atopic dermatitis and diabetes. Furthermore, two independent study populations of patients with type 1 (n=104) or 2 (n=774) diabetes were genotyped. Results In a crude data analysis, a positive association was detected between the filaggrin null genotype and, respectively, subjects from the general population who reported diabetes (p=0.04) and patients with established type 2 diabetes (p=0.073). Adjustment for age and gender resulted in significant associations for patients with type 2 diabetes (p=0.048) and subjects with self-reported diabetes (p=0.032). Conclusions Adult Danes with a filaggrin null genotype had a significantly increased prevalence of self-reported diabetes. This finding was replicated when an independent sample of Danish patients with established type 2 diabetes was compared with control subjects from the general population.

No association between metal allergy and cardiac in-stent restenosis in patients with dermatitis-results from a linkage study.

BACKGROUND: Percutaneous coronary intervention (PCI) with implantation of a metal stent is a common procedure performed in patients with symptomatic ischaemic heart disease. Intracoronary stents typically have a backbone of stainless steel, which contains nickel, chromium, and molybdenum, and it remains unclear whether individuals who are allergic to these metals have an increased risk of restenosis after PCI with stent implantation. OBJECTIVES: To further evaluate whether dermatitis patients with nickel and/or chromium allergy had an increased risk of developing cardiac in-stent restenosis with stainless steel stents. METHODS: An individual-level linkage study was performed to identify dermatitis patients who had been patch tested with the European baseline series between 1979 and 2007 at Gentofte University Hospital (N = 18794) and who had also undergone PCI at some point in a Danish hospital. RESULTS: One hundred and forty-nine (0.8%) dermatitis patients who had undergone PCI with a metal stent were included. One hundred and forty-seven were patch-tested before undergoing PCI. Of the patients, 14.1% (21/149) had cardiac in-stent restenosis. Among patients with metal allergy, 2 (11.8%) had restenosis. CONCLUSIONS: Nickel and/or chromium allergy in dermatitis patients does not appear to increase the overall risk of in-stent restenosis after PCI.

Prevalence of benzocaine and lidocaine patch test sensitivity in Denmark: temporal trends and relevance.

UNLABELLED: BACKGROUND. Allergens included in the European baseline series should result in positive patch test reactions in at least 1% of a patch test population. Inclusion of local anaesthetics other than benzocaine in the baseline series has previously been debated. OBJECTIVES: To investigate temporal trends of benzocaine and lidocaine allergy in dermatitis patients who underwent routine patch testing in a tertiary referral patch test centre, and to clarify and discuss whether lidocaine and benzocaine should be included in routine series. METHODS: Dermatitis patients who underwent routine patch testing with benzocaine as a part of the European baseline series between 1985 and 2010 (n = 19 347) and dermatitis patients who underwent routine patch testing with lidocaine between 1994 and 2001 (n = 6265) and between 2007 and 2009 (n = 1360) were included. RESULTS: The overall prevalences of contact allergy were 0.5% (benzocaine), 0.3% (lidocaine for the period 1994-2001), and 0.14% (lidocaine for the period 2007-2009). Current relevance was observed in 10% of those with benzocaine allergy and in 5% of those with lidocaine allergy. CONCLUSIONS: Benzocaine and lidocaine allergy is infrequent in Danish dermatitis patients. Lidocaine should only be used for aimed testing, and benzocaine should be removed from the baseline series used in Denmark.

Formaldehyde exposure and patterns of concomitant contact allergy to formaldehyde and formaldehyde-releasers.

BACKGROUND: Formaldehyde and formaldehyde-releasers are widely used in consumer products and may often cause contact allergy. OBJECTIVE: To investigate the prevalence of concomitant contact allergy to formaldehyde and formaldehyde-releasers in dermatitis patients, and to determine the sources of formaldehyde exposure based on personal and occupational products obtained from dermatitis patients. METHODS: Patch test data from referred dermatitis patients with a positive patch test reaction to formaldehyde or formaldehyde-releasers were analysed. For the period 2000-2008, the formaldehyde content in products obtained from formaldehyde-allergic patients was analysed by chromotropic acid test and/or acetylacetone test. RESULTS: Patients allergic to a formaldehyde-releaser often had simultaneous contact allergy to formaldehyde. Other combinations were also prevalent. In patients who reacted to more than two formaldehyde-releasers, nearly all reacted simultaneously to formaldehyde. Seventy-five percent of the formaldehyde-allergic patients used a product that contained formaldehyde. The main source of formaldehyde exposure was cosmetics (78%). CONCLUSIONS: Concomitant contact allergy to formaldehyde and formaldehyde-releaser remains common. Furthermore, contact allergy to a formaldehyde-releaser was nearly always concomitant with another formaldehyde-releaser. Formaldehyde was commonly found in personal products used by formaldehyde-allergic patients.

Temporal trends of preservative allergy in Denmark (1985-2008).

BACKGROUND: Most cosmetics and industrial products contain preservatives. Preservative allergy is common and, historically, changing contact allergy epidemics caused by preservatives have been observed. In 1997, Alan Dillarstone predicted a stable development of preservative allergy following mandatory ingredient labelling on cosmetic products. OBJECTIVES: To investigate the development in the prevalence of preservative allergy in Denmark over a 24-year period (1985-2008) and to challenge the prediction made by Dillarstone. PATIENTS/METHODS: A retrospective analysis of patch test data was performed (n = 18179). Comparisons were made using a chi(2) test. Logistic regression analyses were used to test for associations. RESULTS: The development of preservative allergy mirrored those of other European patch test centres. The development was not dependent on sex or age group. The prevalence was higher among women and those aged 41-60 years. Formaldehyde allergy was persistently prevalent over the study years. The overall prevalence of preservative allergy increased significantly (P(trend) = 0.001), mainly because of patch testing with additional preservatives in recent years. CONCLUSIONS: Dillarstone's prediction was confirmed as the prevalence of contact allergy to individual preservatives remained relatively stable. However, the overall burden of preservative allergy seemed to increase. Introduction of new preservatives may add to the burden of contact allergy.

The association between metal allergy, total hip arthroplasty, and revision.

BACKGROUND AND PURPOSE: It has been speculated that the prevalence of metal allergy may be higher in patients with implant failure. We compared the prevalence and cause of revisions following total hip arthroplasty (THA) in dermatitis patients suspected to have contact allergy and in patients in general with THA. Furthermore, we compared the prevalence of metal allergy in dermatitis patients with and without THA. MATERIALS AND METHODS: The Danish Hip Arthroplasty Registry (DHAR) contained detailed information on 90,697 operations. The Gentofte patch-test database contained test results for patients suspected of having allergic contact dermatitis (n = 18,794). Cases (n = 356) were defined as patch-tested dermatitis patients who also had primary THA performed. Two age- and sex-matched controls (n = 712) from the patch-test database were sought for each case. RESULTS: The prevalence of revision was similar in cases (12%) and in patients from the DHAR (13%). The prevalence of metal allergy was similar in cases and controls. However, the prevalence of metal allergy was lower in cases who were patch-tested after operation (6%) than in those who were patch-tested before operation (16%) (OR = 2.9; 95% CI = 1-8). INTERPRETATION: We found that the risk of surgical revision was not increased in patients with metal allergies and that the risk of metal allergy was not increased in cases who were operated, in comparison to controls. Despite some important study limitations, our observations add to the evidence that the risk of complications in metal allergic patients seems limited.

Primin in the European standard patch test series for 20 years.

Primin was included in the European standard series (ESS) in 1984. In 2000, a primin-free variant of Primula obconica, the main source of contact allergy to primin, was introduced in the market. The aim of this study was to analyse the trends of primin allergy in 13 986 consecutively patch-tested eczema patients over a 20-year period from 1985 to 2004. 151 patients gave a positive patch test to primin. The majority were women, in two-third of patients the patch test was relevant and most presented with hand eczema. Only few of the cases (4.7%) were occupational. A significant decline of contact allergy to primin was seen (P < 0.001) over the years affecting all age groups. The frequency was 0.5% during 2000-2004. Contact allergy has been rare since 2000. The low frequency of positive patch test to primin does not support inclusion in the ESS in our region.

Inflammatory bowel disease in relation to contact allergy: a patient-based study.

OBJECTIVE: Inflammatory bowel disease (IBD) has previously been investigated with relation to allergic conditions; however, diverging results were found and there are only a few small studies focusing on delayed hypersensitivity. The aim of this study was to investigate whether there was an association between contact allergy (CA), which is a type IV hypersensitivity reaction of the skin, and IBD. MATERIAL AND METHODS: A database consisting of a cohort of 13,315 patients, patch tested between 1985 and 2003, was linked with the Danish National Patient Registry using a unique personal identifier number. The patients were patch tested at a dermatology department with a long history of research in CA. By record linking with the Danish National Patient Registry, patients were identified who had either an International Classification of Disease (ICD) code for Crohn's disease (CD) or an ICD code for ulcerative colitis (UC) diagnosis. Using logistic regression, with the result of the patch test as the dependent variable, we calculated the odds ratios for IBD, CD and UC, adjusted for gender and age. RESULTS: An inverse association between CA and IBD was found, odds ratio adjusted for age and gender 0.71 (CI 95% 0.53-0.94), which is mainly the result of an inverse association between CA and CD, odds ratio adjusted for age and gender 0.42 (CI 95% 0.23-0.76). CONCLUSIONS: The association found between CA and IBD might be related to shared genetic factors or common environmental determinates. It may also be that having either disease result in skewness of the immune system might lead to an inverse disease association.

Multivariate data analysis of proteome data.

We present the background for multivariate data analysis on proteomics data with a hands-on section on how to transfer data between different software packages. The techniques can also be used for other biological and biochemical problems in which structures have to be found in a large amount of data. Digitalization of the 2D gels, analysis using image processing software, transfer of data, multivariate data analysis, interpretation of the results, and finally we return to biology.