Common FLG Mutation K4671X Not Associated with Atopic Dermatitis in Han Chinese in a Family Association Study

Background

Filaggrin gene (FLG) mutations have been identified as the cause of ichthyosis vulgaris (IV) and major predisposing factors for atopic dermatitis (AD). The relationship among AD, IV and FLG mutations has not been clarified yet. Mutations 3321delA and K4671X, two of the most common mutations in Chinese patients, were both statistically associated with AD in case-control studies.

Materials and Methods

A group of 100 family trios (a total of 300 members with one affected AD proband and both parents) were recruited and screened for three filaggrin null mutations (3222del4, 3321delA and K4671X). The subjects’ manifestations of AD and IV were assessed by two experienced dermatologists and recorded in detail. The relationship of common mutations to AD were assessed using both case-control and family-based tests of association. Filaggrin expression was measured in skin of 3 subjects with K4671X heterozygote and the normal control using quantitative real-time RT-PCR and immunohistochemistry.

Results

Of 100 probands for AD, 22 were carriers for common FLG mutations and only 2 of them were from 40 none-IV family trios (5.00%), consistent with that of the healthy control group (3.99%, P>0.05). Significant statistical associations were revealed between AD and 3321delA (P<0.001, odds ratio 12.28, 95% confidence interval 3.35–44.98) as well as K4671X (P = 0.002, odds ratio 4.53, 95% confidence interval 1.77–11.60). The family-based approach revealed that 3321delA was over-transmitted to AD offspring from parents (T:U = 12∶1, P = 0.003) but failed to demonstrate transmission disequilibrium between K4671X and AD (T:U = 10∶8, P = 0.815). Moreover, compared to the normal control, filaggrin expression at both mRNA and protein levels in epidermis of subjects with K4671X^heter was not reduced.

Conclusions

AD patients from none-IV family trios have low probability of carrying FLG mutations. The present family samples confirmed the susceptibility of mutation 3321delA to AD in Han Chinese. K4671X was not a pathogenic mutation.     

Maternal Filaggrin Mutations Increase the Risk of Atopic Dermatitis in Children: An Effect Independent of Mutation Inheritance

Epidemiological studies suggest that allergy risk is preferentially transmitted through mothers. This can be due to genomic imprinting, where the phenotype effect of an allele depends on its parental origin, or due to maternal effects reflecting the maternal genome''s influence on the child during prenatal development. Loss-of-function mutations in the filaggrin gene (FLG) cause skin barrier deficiency and strongly predispose to atopic dermatitis (AD). We investigated the 4 most prevalent European FLG mutations (c.2282del4, p.R501X, p.R2447X, and p.S3247X) in two samples including 759 and 450 AD families. We used the multinomial and maximum-likelihood approach implemented in the PREMIM/EMIM tool to model parent-of-origin effects. Beyond the known role of FLG inheritance in AD (R1_{meta-analysis} = 2.4, P = 1.0 x 10⁻³⁶), we observed a strong maternal FLG genotype effect that was consistent in both independent family sets and for all 4 mutations analysed. Overall, children of FLG-carrier mothers had a 1.5-fold increased AD risk (S1 = 1.50, P_{meta-analysis} = 8.4 x 10⁻⁸). Our data point to two independent and additive effects of FLG mutations: i) carrying a mutation and ii) having a mutation carrier mother. The maternal genotype effect was independent of mutation inheritance and can be seen as a non-genetic transmission of a genetic effect. The FLG maternal effect was observed only when mothers had allergic sensitization (elevated allergen-specific IgE antibody plasma levels), suggesting that FLG mutation-induced systemic immune responses in the mother may influence AD risk in the child. Notably, the maternal effect reported here was stronger than most common genetic risk factors for AD recently identified through genome-wide association studies (GWAS). Our study highlights the power of family-based studies in the identification of new etiological mechanisms and reveals, for the first time, a direct influence of the maternal genotype on the offspring’s susceptibility to a common human disease.     

T regulatory cells in cord blood--FOXP3 demethylation as reliable quantitative marker

Background

Regulatory T-cells (Tregs), characterized as CD4+CD25^hi T-cells expressing FOXP3, play a crucial role in controlling healthy immune development during early immune maturation. Recently, FOXP3 demethylation was suggested to be a novel marker for natural Tregs in adults. In cord blood, the role and function of Tregs and its demethylation is poorly understood. We assessed FOXP3 demethylation in cord blood in relation to previously used Treg markers such as CD4⁺CD25^hi, FOXP3 mRNA, protein expression, and suppressive Treg function.

Methodology

Cord blood mononuclear cells (CBMC) were isolated from 70 healthy neonates, stimulated for 3 days with the microbial stimulus lipid A (LpA), and allergen Dermatophagoides pteronyssinus (Derp1). Tregs (CD4+CD25^hi, intracellular, mRNA FOXP3 expression, isolated cells), DNA methylation of the FOXP3-locus and suppressive Treg function were assessed.

Principal Findings

Demethylation of FOXP3 in whole blood was specific for isolated CD4+CD25^hi Tregs. Demethylation of FOXP3 was positively correlated with unstimulated and LpA-stimulated FOXP3 mRNA-expression (p≤0.05), and CD4⁺CD25^hi T-cells (p≤0.03). Importantly, increased FOXP3 demethylation correlated with more efficient suppressive capacity of Tregs (r = 0.72, p = 0.005). Furthermore, FOXP3 demethylation was positively correlated with Th2 cytokines (IL-5, IL-13) following LpA-stimulation (p = 0.006/0.04), with Th2 and IL-17 following Derp1+LpA-stimulations (p≤0.009), but not Th1 cytokines (IFN-γ).

Conclusions

FOXP3 demethylation reliable quantifies Tregs in cord blood. FOXP3 demethylation corresponds well with the suppressive potential of Tregs. The resulting strict correlation with functionally suppressive Tregs and the relative ease of measurement render it into a valuable novel marker for large field studies assessing Tregs as qualitative marker indicative of functional activity.     

Increased Presence of FOXP3+ Regulatory T Cells in Inflamed Muscle of Patients with Active Juvenile Dermatomyositis Compared to Peripheral Blood

Juvenile dermatomyositis (JDM) is an immune-mediated inflammatory disease affecting the microvasculature of skin and muscle. CD4⁺CD25⁺FOXP3⁺ regulatory T cells (Tregs) are key regulators of immune homeostasis. A role for Tregs in JDM pathogenesis has not yet been established. Here, we explored Treg presence and function in peripheral blood and muscle of JDM patients. We analyzed number, phenotype and function of Tregs in blood from JDM patients by flow cytometry and in vitro suppression assays, in comparison to healthy controls and disease controls (Duchenne’s Muscular Dystrophy). Presence of Tregs in muscle was analyzed by immunohistochemistry. Overall, Treg percentages in peripheral blood of JDM patients were similar compared to both control groups. Muscle biopsies of new onset JDM patients showed increased infiltration of numbers of T cells compared to Duchenne’s muscular dystrophy. Both in JDM and Duchenne’s muscular dystrophy the proportion of FOXP3⁺ T cells in muscles were increased compared to JDM peripheral blood. Interestingly, JDM is not a self-remitting disease, suggesting that the high proportion of Tregs in inflamed muscle do not suppress inflammation. In line with this, peripheral blood Tregs of active JDM patients were less capable of suppressing effector T cell activation in vitro, compared to Tregs of JDM in clinical remission. These data show a functional impairment of Tregs in a proportion of patients with active disease, and suggest a regulatory role for Tregs in JDM inflammation.     

Genetic Variation in the Epidermal Transglutaminase Genes Is Not Associated with Atopic Dermatitis

Background

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder where epidermal barrier dysfunction is a major factor in the pathogenesis. The identification of AD susceptibility genes related to barrier dysfunction is therefore of importance. The epidermal transglutaminases (TGM1, TGM3 and TGM5) encodes essential cross-linking enzymes in the epidermis.

Objective

To determine whether genetic variability in the epidermal transglutaminases contributes to AD susceptibility.

Methods

Forty-seven single nucleotide polymorphisms (SNPs) in the TGM1, TGM3 and TGM5 gene region were tested for genetic association with AD, independently and in relation to FLG genotype, using a pedigree disequilibrium test (PDT) in a Swedish material consisting of 1753 individuals from 539 families. In addition, a German case-control material, consisting of 533 AD cases and 1996 controls, was used for in silico analysis of the epidermal TGM regions. Gene expression of the TGM1, TGM3 and TGM5 gene was investigated by relative quantification with Real Time PCR (qRT-PCR). Immunohistochemical (IHC) analysis was performed to detect TG1, TG3 and TG5 protein expression in the skin of patients and healthy controls.

Results

PDT analysis identified a significant association between the TGM1 SNP rs941505 and AD with allergen-specific IgE in the Swedish AD family material. However, the association was not replicated in the German case-control material. No significant association was detected for analyzed SNPs in relation to FLG genotype. TG1, TG3 and TG5 protein expression was detected in AD skin and a significantly increased TGM3 mRNA expression was observed in lesional skin by qRT-PCR.

Conclusion

Although TGM1 and TGM3 may be differentially expressed in AD skin, the results from the genetic analysis suggest that genetic variation in the epidermal transglutaminases is not an important factor in AD susceptibility.     

Impaired survival of regulatory T cells in pulmonary sarcoidosis

Background

Impaired regulatory T cell (Treg) function is thought to contribute to ongoing inflammatory responses in sarcoidosis, but underlying mechanisms remain unclear. Moreover, it is not known if increased apoptotic susceptibility of Tregs may contribute to an impaired immunosuppressive function in sarcoidosis. Therefore, the aim of this study is to analyze proportions, phenotype, survival, and apoptotic susceptibility of Tregs in sarcoidosis.

Methods

Patients with pulmonary sarcoidosis (n = 58) were included at time of diagnosis. Tregs were analyzed in broncho-alveolar lavage fluid and peripheral blood of patients and healthy controls (HC).

Results

In sarcoidosis patients no evidence was found for a relative deficit of Tregs, neither locally nor systemically. Rather, increased proportions of circulating Tregs were observed, most prominently in patients developing chronic disease. Sarcoidosis circulating Tregs displayed adequate expression of FoxP3, CD25 and CTLA4. Remarkably, in sarcoidosis enhanced CD95 expression on circulating activated CD45RO⁺ Tregs was observed compared with HC, and proportions of these cells were significantly increased. Specifically sarcoidosis Tregs - but not Th cells - showed impaired survival compared with HC. Finally, CD95L-mediated apoptosis was enhanced in sarcoidosis Tregs.

Conclusion

In untreated patients with active pulmonary sarcoidosis, Tregs show impaired survival and enhanced apoptotic susceptibility towards CD95L. Increased apoptosis likely contributes to the insufficient immunosuppressive function of sarcoidosis Tregs. Further research into this field will help determine whether improvement of Treg survival holds a promising new therapeutic approach for chronic sarcoidosis patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0265-8) contains supplementary material, which is available to authorized users.     

Filaggrin gene defects are independent risk factors for atopic asthma in a Polish population: a study in ECAP cohort

Background

FLG null variants of which 2282del4 and R501X are the most frequent in Caucasians are established risk factors for atopic dermatitis (AD) with an effect probably mediated through impairment of epidermal barrier. Among subjects with AD FLG defects are also consistently associated with asthma and allergic rhinitis (AR) but it is less clear to what extent these associations are also present independently from skin disease. The aim of the present study was to evaluate the role of 2282del4 and R501X in predisposing to these allergic phenotypes in a Polish population.

Methodology

2282del4 and R501X were typed among 3,802 participants of the Epidemiology of Allergic Diseases in Poland (ECAP) survey, a cross-sectional population-based study using ECRHS II and ISAAC questionnaires, and ambulatory examination.

Principal Findings

The FLG null variants were associated with AD (OR = 2.01, CI: 1.20–3.36, P = 0.007), allergic rhinitis (in particular persistent form, OR = 1.69, CI:1.12–2.54, P = 0.011), and asthma (in particular atopic asthma, OR = 2.22, CI:1.24–3.96, P = 0.006). Association with atopic asthma (but not persistent allergic rhinitis) was also present in the absence of AD, (OR = 2.02, CI: 1.07–3.81, P = 0.027) as well as in the absence of AD and history of broadly defined inflammatory skin disease (OR = 2.30, CI: 1.07–4.93, P = 0.03). Association to atopic asthma would have not been found if diagnosis was made by questionnaire only (OR = 1.15, CI: 0.58–2.32, P = 0.8). We did not observe an association between FLG variants and allergic sensitizations (P = 0.8) or total IgE. (P = 0.6).

Conclusions/Significance

In a Polish population FLG 2282del4 and R501X carriage increases risk for development of AD and atopic asthma (also in the absence of AD or history thereof). This suggests that interventions aimed at restoring epidermal barrier may have a general role in asthma prophylaxis/treatment.     

Cigarette Smoking Promotes Inflammation in Patients with COPD by Affecting the Polarization and Survival of Th/Tregs through Up-Regulation of Muscarinic Receptor 3 and 5 Expression

Background

CD4⁺ T cells in the lung are involved in the pathogenesis of chronic obstructive pulmonary disease (COPD), although CD4⁺ T cell subsets and the direct effect of smoking on these cells, especially the expression of MRs, have not been comprehensively examined.

Methods

First, circulating CD4⁺ T cell subsets in healthy nonsmokers, patients with SCOPD and patients with AECOPD were evaluated by flow cytometry. Then, differentiation experiments were carried out using RT-PCR, and Ki-67/Annexin V antibodies were used to measure proliferation and apoptosis. We also explored the impact of CSE on the differentiation and survival of CD4⁺Th/Tregs and examined the expression of MRs in healthy nonsmokers and patients with SCOPD.

Results

We found the percentages of circulating Th1 and Th17 cells were increased in patients with AECOPD, while the percentage of Th2 cells was decreased in patients with SCOPD. The percentages of Th10 cells were decreased in both patients with SCOPD and patients with AECOPD, while the percentages of Tregs were increased. In addition, the percentages of CD4⁺α-7⁺ T cells were decreased in patients with SCOPD and patients with AECOPD. However, only the decrease observed in patients with AECOPD was significant. In vitro studies also revealed MR expression affected the polarization of T cells, with different CD4⁺ T cell subtypes acquiring different MR expression profiles. The addition of CSE facilitated CD4⁺ T cell polarization towards pro-inflammatory subsets (Th1 and Th17) and affected the survival of CD4⁺ T cells and Treg cells by up-regulating the expression of MR3 and 5, resulting in an imbalance of CD4⁺ T cell subsets.

Conclusions

Our findings suggest an imbalance of circulating CD4⁺ T cell subsets is involved in COPD pathogenesis in smokers. Cigarette smoking may contribute to this imbalance by affecting the polarization and survival of Th/Tregs through the up-regulation of MR3 and MR5.     

Predominance of PR3 specific immune response and skewed TH17 vs. T-regulatory milieu in active granulomatosis with polyangiitis

ObjectiveWe compared levels of Th1/Th2/Th17 cytokines and T-regulatory cells in active and remitting granulomatosis with polyangiitis (GPA).MethodologyTwenty-one cases of GPA in active state as well as in remitting state and 20 healthy controls (HC) were enrolled in the study. Cytokines were detected in culture supernatants of PBMCs after stimulation with proteinase-3 (PR3) and phytohemagglutinin antigen (PHA). Serum IL-17 cytokine was studied by ELISA. T-regulatory cells (Tregs) were analyzed by flow cytometry. Gene expression of FOXP3 and ROR-γt was compared by Real Time PCR.ResultsWe observed significantly increased level of IL-17 in serum as well in culture supernatants of PBMCs after PR3 stimulation along with ROR-γt gene expression in active disease state of GPA as compared to HC. Importantly, remitting state showed low levels of serum IL-17 with decreased ROR-γt gene expression and increased FOXP3 expression. Using PR3 as an immunostimulant, we could demonstrate the generation of IL-17 and TNF-α secreting effector memory cells during remission. Reduced FOXP3 expression with reduced IL-10 levels in active disease indicated the reduced function of Tregs in active disease.ConclusionWe observed Th17 dominant environment in peripheral blood of patients in active state of disease, with “hyporesponsiveness”, in, in vitro stimulated PBMC-in their ability to secrete TNF-α and IL-6. Treg numbers were unaltered but function was compromised. Targeting PR3 specific effector memory cells, to prevent relapse, and instituting anti IL-17 therapy, or modulating Tregs could be newer forms of therapy for this serious autoimmune disease.     

Targeting prohibitins at the cell surface prevents Th17‐mediated autoimmunity

T helper (Th)17 cells represent a unique subset of CD4⁺ T cells and are vital for clearance of extracellular pathogens including bacteria and fungi. However, Th17 cells are also involved in orchestrating autoimmunity. By employing quantitative surface proteomics, we found that the evolutionarily conserved prohibitins (PHB1/2) are highly expressed on the surface of both murine and human Th17 cells. Increased expression of PHBs at the cell surface contributed to enhanced CRAF/MAPK activation in Th17 cells. Targeting surface‐expressed PHBs on Th17 cells with ligands such as Vi polysaccharide (Typhim vaccine) inhibited CRAF‐MAPK pathway, reduced interleukin (IL)‐17 expression and ameliorated disease pathology with an increase in FOXP3⁺‐expressing Tregs in an animal model for multiple sclerosis (MS). Interestingly, we detected a CD4⁺ T cell population with high PHB1 surface expression in blood samples from MS patients in comparison with age‐ and sex‐matched healthy subjects. Our observations suggest a pivotal role for the PHB‐CRAF‐MAPK signalling axis in regulating the polarization and pathogenicity of Th17 cells and unveil druggable targets in autoimmune disorders such as MS.     

Systemic analyses of immunophenotypes of peripheral T cells in non-segmental vitiligo: implication of defective natural killer T cells

Although it is widely believed that non‐segmental vitiligo (NSV) results from the autoimmune destruction of melanocytes, a clear understanding of defects in immune tolerance, which mediate this uncontrolled self‐reactivity, is still lacking. In the present study, we systemically evaluated circulating regulatory T (Treg) cells, including CD4⁺CD25⁺FoxP3⁺ Treg cells and invariant natural killer T (iNKT) cells, as well as naïve and memory CD4⁺ and CD8⁺ T cells and their cytokine production, in a cohort of 43 progressive NSV patients with race‐, gender‐, and age‐matched healthy controls. We found that the general immunophenotypes of CD4⁺ and CD8⁺ T cells and the percentage of CD4⁺CD25⁺FoxP3⁺ Tregs were comparable between NSV and healthy controls. However, percentages of peripheral iNKT cells were significantly decreased in NSV patients compared to that in healthy controls. Our data confirm the previous notion that the percentage of peripheral CD4⁺CD25⁺FoxP3⁺ Tregs remains unaltered in NSV and suggests the involvement of defective iNKT cells in the pathogenesis of NSV.     

The Ratio of Circulating Regulatory T Cells (Tregs)/Th17 Cells Is Associated with Acute Allograft Rejection in Liver Transplantation

CD4⁺CD25⁺FoxP3⁺ regulatory T cells (Tregs) and Th17 cells are known to be involved in the alloreactive responses in organ transplantation, but little is known about the relationship between Tregs and Th17 cells in the context of liver alloresponse. Here, we investigated whether the circulating Tregs/Th17 ratio is associated with acute allograft rejection in liver transplantation. In present study, thirty-eight patients who received liver transplant were enrolled. The patients were divided into two groups: acute allograft rejection group (Gr-AR) (n = 16) and stable allograft liver function group (Gr-SF) (n = 22). The frequencies of circulating Tregs and circulating Th17 cells, as well as Tregs/Th17 ratio were determined using flow cytometry. The association between Tregs/Th17 ratio and acute allograft rejection was then analyzed. Our results showed that the frequency of circulating Tregs was significantly decreased, whereas the frequency of circulating Th17 cells was significantly increased in liver allograft recipients who developed acute rejection. Tregs/Th17 ratio had a negative correlation with liver damage indices and the score of rejection activity index (RAI) after liver transplantation. In addition, the percentages of CTLA-4⁺, HLA-DR⁺, Ki67⁺, and IL-10⁺ Tregs were higher in Gr-SF group than in Gr-AR group. Our results suggested that the ratio of circulating Tregs/Th17 cells is associated with acute allograft rejection, thus the ratio may serve as an alternative marker for the diagnosis of acute rejection.     

AKT isoforms modulate Th1‐like Treg generation and function in human autoimmune disease

Foxp3⁺ regulatory T cells (Tregs) exhibit plasticity, which dictates their function. Secretion of the inflammatory cytokine IFNγ, together with the acquisition of a T helper 1 (Th1)‐like effector phenotype as observed in cancer, infection, and autoimmune diseases, is associated with loss of Treg suppressor function through an unknown mechanism. Here, we describe the signaling events driving the generation of human Th1‐Tregs. Using a genome‐wide gene expression approach and pathway analysis, we identify the PI3K/AKT/Foxo1/3 signaling cascade as the major pathway involved in IFNγ secretion by human Tregs. Furthermore, we describe the opposing roles of AKT isoforms in Th1‐Treg generation ex vivo. Finally, we employ multiple sclerosis as an in vivo model with increased but functionally defective Th1‐Tregs. We show that the PI3K/AKT/Foxo1/3 pathway is activated in ex vivo‐isolated Tregs from untreated relapsing–remitting MS patients and that blockade of the pathway inhibits IFNγ secretion and restores the immune suppressive function of Tregs. These data define a fundamental pathway regulating the function of human Tregs and suggest a novel treatment paradigm for autoimmune diseases.     

Decreased IL-15 may contribute to elevated IgE and acute inflammation in atopic dermatitis.

PBMC and acute skin lesions of patients with atopic dermatitis (AD) are characterized by increased IL-4 and IL-13, but decreased IFN-gamma production. This bias toward an increased Th2 cytokine profile may contribute to the elevated IgE levels and acute skin inflammation seen in AD. In this study, we examined the levels of IL-15, a Th1-like cytokine, in the PBMC and the skin lesions of AD patients. IL-15 secretion by Staphylococcal enterotoxin B-treated PBMC of AD patients was significantly lower than that of normals and psoriasis patients (p < 0.001). Membrane-bound IL-15 expression as measured by mean fluorescence intensity and percentage of IL-15-positive cells in Staphylococcal enterotoxin B-treated monocytes of AD patients (644 +/- 49% and 12.7 +/- 0.6%, respectively) were significantly lower than that of normals (869 +/- 56% and 15.8 +/- 1.2%, respectively) and psoriasis patients (1488 +/- 217% and 22.7 +/- 0.8%, respectively; p < 0.0007 and p < 0.0001, respectively). The membrane-bound IL-15 expression was also significantly lower in the control monocytes of AD patients compared with that in normals and psoriasis patients. There was no significant difference in the absolute number or percentage of monocytes between the study subjects. However, psoriasis skin lesions were found to have significantly more IL-15 mRNA-expressing cells (22.4 +/- 1.7) compared with that in acute AD (7.5 +/- 1.7) and chronic AD (13.7 +/- 1.7) skin lesions (p < 0.05). IL-15 enhanced IFN-gamma production by the PBMC of AD patients (p < 0.01), but not by that of normal individuals or psoriasis patients. In addition, IL-15 was found to suppress IgE synthesis (p < 0.01) by the PBMC of AD patients. These data support the concept that reduced IL-15 expression may contribute to the pathogenesis of AD.     

Filaggrin genotype determines functional and molecular alterations in skin of patients with atopic dermatitis and ichthyosis vulgaris

Background

Several common genetic and environmental disease mechanisms are important for the pathophysiology behind atopic dermatitis (AD). Filaggrin (FLG) loss-of-function is of great significance for barrier impairment in AD and ichthyosis vulgaris (IV), which is commonly associated with AD. The molecular background is, however, complex and various clusters of genes are altered, including inflammatory and epidermal-differentiation genes.

Objective

The objective was to study whether the functional and molecular alterations in AD and IV skin depend directly on FLG loss-of-function, and whether FLG genotype determines the type of downstream molecular pathway affected.

Methods and Findings

Patients with AD/IV (n = 43) and controls (n = 15) were recruited from two Swedish outpatient clinics and a Swedish AD family material with known FLG genotype. They were clinically examined and their medical history recorded using a standardized questionnaire. Blood samples and punch biopsies were taken and trans-epidermal water loss (TEWL) and skin pH was assessed with standard techniques. In addition to FLG genotyping, the STS gene was analyzed to exclude X-linked recessive ichthyosis (XLI). Microarrays and quantitative real-time PCR were used to compare differences in gene expression depending on FLG genotype. Several different signalling pathways were altered depending on FLG genotype in patients suffering from AD or AD/IV. Disease severity, TEWL and pH follow FLG deficiency in the skin; and the number of altered genes and pathways are correlated to FLG mRNA expression.

Conclusions

We emphasize further the role of FLG in skin-barrier integrity and the complex compensatory activation of signalling pathways. This involves inflammation, epidermal differentiation, lipid metabolism, cell signalling and adhesion in response to FLG-dependent skin-barrier dysfunction.     

Plasticity of human regulatory T cells in healthy subjects and patients with type 1 diabetes

Regulatory T cells (Tregs) constitute an attractive therapeutic target given their essential role in controlling autoimmunity. However, recent animal studies provide evidence for functional heterogeneity and lineage plasticity within the Treg compartment. To understand better the plasticity of human Tregs in the context of type 1 diabetes, we characterized an IFN-γ-competent subset of human CD4(+)CD127(lo/-)CD25(+) Tregs. We measured the frequency of Tregs in the peripheral blood of patients with type 1 diabetes by epigenetic analysis of the Treg-specific demethylated region (TSDR) and the frequency of the IFN-γ(+) subset by flow cytometry. Purified IFN-γ(+) Tregs were assessed for suppressive function, degree of TSDR demethylation, and expression of Treg lineage markers FOXP3 and Helios. The frequency of Tregs in peripheral blood was comparable but the FOXP3(+)IFN-γ(+) fraction was significantly increased in patients with type 1 diabetes compared to healthy controls. Purified IFN-γ(+) Tregs expressed FOXP3 and possessed suppressive activity but lacked Helios expression and were predominately methylated at the TSDR, characteristics of an adaptive Treg. Naive Tregs were capable of upregulating expression of Th1-associated T-bet, CXCR3, and IFN-γ in response to IL-12. Notably, naive, thymic-derived natural Tregs also demonstrated the capacity for Th1 differentiation without concomitant loss of Helios expression or TSDR demethylation.     

Clinical significance of weak interleukin‐35 expression in patients with psoriasis

CD4+T cells and their related cytokines play an important role in the pathogenesis of psoriasis, a chronic, recurrent, inflammatory skin disease. The role of IL‐35, an immunosuppressive cytokine involved in many autoimmune diseases, in the pathogenesis of psoriasis is unclear. In this study IL‐35 expression and its clinical significance in patients with psoriasis were evaluated. Protein and mRNA levels of specified markers were measured by ELISA and qRT‐PCR, respectively. It was found that plasma IL‐35 concentrations were lower in patients with psoriasis than in healthy individuals (Z = ?6.525, P < 0.0001). mRNA titers of Ebi3 and p35 were lower in peripheral blood mononuclear cells from patients with psoriasis than in those from healthy individuals (Z = ?5.078, P < 0.0001; Z = ?2.609, P = 0.009, respectively). The areas under the receiver‐operating characteristic (ROC) curves for IL‐35, Ebi3 and p35 in patients with psoriasis versus controls were 0.86, 0.78 and 0.64, respectively. Pearson correlation analysis showed that, in patients with psoriasis, plasma IL‐35 expression correlated negatively with concentrations of INF‐γ, tumor necrosis factor‐alpha, IL‐23, ?17, and ?22, and the Psoriasis Activity and Severity Index and positively with concentrations of transforming growth factor beta and IL‐10 . In summary, IL‐35 may mediate pathogenesis of psoriasis by influencing expression of Th1/Th17/T_reg‐related cytokines and may therefore be a putative target for monitoring or treating psoriasis.

     

Oral administration of Lactobacillus strains from Kimchi inhibits atopic dermatitis in NC / Nga mice

Aims: Atopic dermatitis (AD) is marked by elevated levels of immunoglobulin E and skin lesions such as oedema and haemorrhage. Kimchi is a Korean fermented food that contains beneficial bacteria for human health. In this study, Lactobacillus plantarum CJLP55, CJLP56, CJLP133 and CJLP136 isolated from Kimchi were investigated for their capacity to inhibit AD. Methods and Results: The three strains, CJLP55, CJLP133 and CJLP136, suppressed AD‐like skin lesions, high serum IgE levels and epidermal thickening. The three strains diminished the accumulation of eosinophils and mast cells into topical inflammatory sites and the enlargement of axillary lymph nodes, which are responsible for the dorsal dermatitis. CJLP55, CJLP133 and CJLP136 decreased production of type 2 cytokines such as IL‐4 and IL‐5 in lymph node cell culture. CJLP133 and CJLP136 increased IFN‐γ secretion, while CJLP55 enhanced IL‐10 production. Conclusions: The three strains isolated from Kimchi suppress house‐dust mite‐induced dermatitis in NC/Nga mouse, a representative animal model of human AD. Significance and Impact of the Study: These findings suggest that lactobacilli isolated from Kimchi inhibit AD, probably by altering the balance of Th1/Th2 ratio or inducing IL‐10 production.