Increased serum B cell-activating factor level in children with atopic dermatitis

Characterization of CD19+ CD24hi CD38hi B cells in Chinese adult patients with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease. Human interleukin-10⁺ B cells (B10 cells) is one of regulatory B cells and is enriched in CD19⁺ CD24^hi CD38^hi B cells. A little is known about these cells in atopic dermatitis.

OBJECTIVE

To study CD19⁺ CD24^hi CD38^hi B cells and their clinical significance in Chinese adult patients with atopic dermatitis.

METHODS

Thirty-two adult patients with AD and nineteen healthy controls were enrolled. Peripheral blood mononuclear cells (PBMCs) were isolated and stained with fluorescein-conjugated monoclonal antibodies for CD19, CD24, CD27, CD38 and Annexin V. The stained PBMCs were analysed by flow cytometry. B10 cells were prepared by stimulating PBMCs with CpG, LPS and CD40L followed by restimulation with phorbol12-myristate 13-acetate (PMA) and ionomycin. Serum IL-10, B-cell-activating factor (BAFF) and a proliferation-inducing ligand (APRIL) levels were measured by using the ELISA. Apoptosis and proliferation of CD19⁺ CD24^hi CD38^hi B cells were measured by flow cytometry. 4/P-signal transducer and activator of transcription 3 (STAT3) and extracellular signal-regulated kinase 1/2 (Erk) phosphorylation were also studied.

RESULTS

The number of CD19⁺ CD24^hi CD38^hi B cells in patients with AD was similar to that in healthy controls. However, B10 cells were decreased in patients with AD. The proportion of B10 cells was negatively associated with blood basophil counts but not associated with disease activity. CD19⁺ CD24^hi CD38^hi B cells from AD patients were more susceptible to apoptosis upon stimulation with CpG, LPS and CD40L. B cells from AD patients showed lower STAT3 and Erk phosphorylation.

CONCLUSIONS

CD19⁺ CD24^hi CD38^hi B cells were unchanged in atopic dermatitis while B10 cells were decreased. The increased B-cell apoptosis, decreased STAT3 and Erk phosphorylation might contribute to these changes.

Serum biomarkers for allergy in children

A large number of studies investigating various biomarkers for allergy have been published over the past decades. The aim of this review was to evaluate these biomarkers on their diagnostic and/or predictive value. To this date, no single or specific biomarker for allergy has been identified. As allergy is not one disease, but a collection of a number of allergic conditions, it is more plausible a combination of clinical history, clinical readouts, and diagnostic markers will be needed.

Herbal Medicines Prevent the Development of Atopic Dermatitis by Multiple Mechanisms

Atopic dermatitis (AD) is among the most common skin disorders in humans. Although a variety of regimens are available for the treatment of AD, preventive approaches are limited. Recent studies have demonstrated that certain naturally-occurring herbal medicines are effective in preventing the development of AD via divergent mechanisms, such as inhibiting cytokine and chemokine expression, IgE production, inflammatory cell infiltration, histamine release, and/or enhancement of epidermal permeability barrier function. Yet, they exhibit few adverse effects. Since herbal medicines are widely available, inexpensive and generally safe, they could represent an ideal approach for preventing the development of AD, in both highly developed and developing countries.

The strength of the antibody response to the nematode Ascaris lumbricoides inversely correlates with levels of B-Cell Activating Factor (BAFF)

Background

B-Cell Activating Factor (BAFF) is a cytokine regulating antibody production. Polymorphisms in the gene encoding BAFF were associated with the antibody response to Ascaris but not to mite allergens. In the present study we evaluated the relationship between BAFF and specific antibodies against Ascaris and mites in 448 controls and 448 asthmatics. Soluble BAFF was measured by ELISA and BAFF mRNA by qPCR. Surface expression of BAFF and its receptor (BAFF-R) was analyzed by flow cytometry.

Results

Individuals with specific IgE levels to Ascaris >75th percentile had lower levels of soluble BAFF; those with specific IgG levels to Ascaris >75th percentile had reduced BAFF mRNA. Total IgE and specific IgE to mites were not related to BAFF levels. There were no differences in soluble BAFF or mRNA levels between asthmatics and controls. There was an inverse relationship between the cell-surface expression of BAFF-R on CD19⁺ B cells and BAFF levels at the transcriptional and protein level.

Conclusions

These findings suggest that differences in BAFF levels are related to the strength of the antibody response to Ascaris.

The clinical and immunomodulatory effects of green soybean extracts

The present study was performed to investigate the immune-modulating activities of extracts from green soybean (Glycine max) in a 2,4-toluene diisocyanate (TDI)-inducing guinea pig rhinitis model and a human trial study for allergic rhinitis. Hot water extracts of green soybean were chosen for animal experimentation on the basis of their ability to regulate the production of B cell-activating factor of the TNF family and a proliferation-inducing ligand in mouse spleen cells. Green soybean extracts significantly decreased the levels of ovalubumin (OVA)-specific IgE in mice and significantly suppressed the TDI-induced nasal mucosa secretion. An open-label human pilot study was performed on 16 subjects, using Japanese cedar pollinosis. The symptom scores for Japanese cedar pollinosis were better in the long-term green soybean extracts intake group than in the withdrawal short-term intake group. Green soybean extracts had great potential as an orally active immune modulator for the treatment of various allergic diseases.

Serum BAFF and APRIL levels in patients with IgG4-related disease and their clinical significance

INTRODUCTION

B cell-activating factor of the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) play a crucial role in B cell development, survival, and antibody production. Here we analyzed the serum levels of BAFF and APRIL and their respective clinical associations in patients with an immunoglobulin (Ig) G4-related disease (IgG4-RD).

METHODS

We measured serum levels of BAFF and APRIL in patients with IgG4-RD, primary Sjögren's syndrome (pSS), and healthy individuals. Serum BAFF and APRIL levels in IgG4-RD were assessed for correlations with serological parameters, including Ig, particularly IgG4, and the number of affected organs. Serum BAFF and APRIL levels in IgG4-RD were monitored during glucocorticoid (GC) therapy.

RESULTS

Serum BAFF and APRIL levels in patients with IgG4-RD were significantly higher (P < 0.01) than in healthy individuals. The BAFF levels of patients with IgG4-RD were comparable to those of patients with pSS. Although clinical parameters, such as serum IgG4 and the number of affected organs, were not correlated with the levels of BAFF, serum APRIL levels were inversely correlated with serum IgG4 levels (r = -0.626, P < 0.05). While serum BAFF levels decreased following GC therapy, serum APRIL levels increased during follow-up.

CONCLUSION

These results indicate that BAFF and APRIL might be useful markers for predicting disease activity in IgG4-RD. Further studies are needed to elucidate the role of BAFF and APRIL in the pathogenesis of IgG4-RD.

B type CpG-DNA suppresses poly(I:C)-induced BLyS expression and production in human tonsillar fibroblasts

Although B lymphocyte stimulator (BLyS) has potent costimulatory effects on B cells, the details of BLyS-expression in tonsillar fibroblasts remain unexplored. We examined the effect of the Toll-like receptor (TLR) ligands on BLyS-expression in human tonsillar fibroblasts as well as the crosstalk that occurs among different TLR ligands. The expression of BLyS mRNA by tonsillar fibroblasts was strongly induced in the presence of polyinosinic-polycytidylic acid (poly(I:C)) that is a ligand, of TLR3. We also revealed that DNA containing CpG motifs (CpG-DNA), coding for a TLR9 ligand, markedly suppressed the poly(I:C)-induced mRNA expression and protein production of BLyS. B type CpG-DNA decreased the poly(I:C)-induced phosphorylation of inhibitor kappa B alpha (IκBα) and its degradation. Pre-incubation with nuclear factor kappa B (NF-κB) signaling inhibitors reduced the poly(I:C)-induced BLyS-expression. These results indicate that human tonsillar fibroblasts strongly induce BLyS-expression and production that can be inhibited by CpG-DNA and regulated through NF-κB signaling.

The expression of BAFF, APRIL and TWEAK is altered in eczema skin but not in the circulation of atopic and seborrheic eczema patients

The TNF family cytokines BAFF (B-cell activating factor of the TNF family) and APRIL (a proliferation-inducing ligand) are crucial survival factors for B-cell development and activation. B-cell directed treatments have been shown to improve atopic eczema (AE), suggesting the involvement of these cytokines in the pathogenesis of AE. We therefore analyzed the expression of these TNF cytokines in AE, seborrheic eczema (SE) and healthy controls (HC). The serum/plasma concentration of BAFF, APRIL and a close TNF member TWEAK (TNF-like weak inducer of apoptosis) was measured by ELISA. The expression of these cytokines and their receptors in skin was analyzed by quantitative RT-PCR and immunofluorescence. Unlike other inflammatory diseases including autoimmune diseases and asthma, the circulating levels of BAFF, APRIL and TWEAK were not elevated in AE or SE patients compared with HCs and did not correlate with the disease severity or systemic IgE levels in AE patients. Interestingly, we found that the expression of these cytokines and their receptors was altered in positive atopy patch test reactions in AE patients (APT-AE) and in lesional skin of AE and SE patients. The expression of APRIL was decreased and the expression of BAFF was increased in eczema skin of AE and SE, which could contribute to a reduced negative regulatory input on B-cells. This was found to be more pronounced in APT-AE, the initiating acute stage of AE, which may result in dysregulation of over-activated B-cells. Furthermore, the expression levels of TWEAK and its receptor positively correlated to each other in SE lesions, but inversely correlated in AE lesions. These results shed light on potential pathogenic roles of these TNF factors in AE and SE, and pinpoint a potential of tailored treatments towards these factors in AE and SE.

Adaptive immune response in osteoclastic bone resorption induced by orally administered Aggregatibacter actinomycetemcomitans in a rat model of periodontal disease

There is mounting evidence that innate and adaptive immunity are critical for periodontal disease-mediated bone resorption. These studies examined the role of B and CD4 T cells in adaptive immunity of rats infected with Aggregatibacter actinomycetemcomitans (Aa). Sprague-Dawley male rats were fed Aa-containing mash or control-mash for 2 weeks. B and CD4 T cells were obtained from draining lymph nodes at 2, 4 and 12 weeks, postinoculation. Quantitative polymerase chain reaction-based messenger RNA expression was conducted for 89 cytokine family genes. Disease-relevance of the differentially expressed genes was assessed using a biological interaction pathway analysis software. B and CD4 T cells of Aa-infected rats increased and were activated, resulting in enhanced isotype-switched serum immunoglobulin G by 2 weeks postinoculation. Bone resorption was evident 12 weeks after Aa-feeding. In B cells, interleukin-2 (IL-2), macrophage-inhibiting factor, IL-19, IL-21, tumor necrosis factor (TNF), CD40 ligand (CD40L), CD70, bone morphogenetic protein 2 (BMP2), BMP3, and BMP10 were upregulated early; while IL-7, Fas ligand (FasL), small inducible cytokine subfamily E1, and growth differentiation factor 11 (GDF11; BMP11) were upregulated late (12 weeks). BMP10 was sustained throughout. In CD4 T cells, IL-10, IL-16, TNF, lymphotoxin-beta (LTbeta), APRIL, CD40L, FasL, RANKL and osteoprotegerin were upregulated early, whereas IL-1beta, IL-1RN, IL-1F8, IL-24, interferon-alpha1, GDF11 (BMP11), and GDF15 were upregulated late (12 weeks). Adaptive immunity appears crucial for bone resorption. Several of the deregulated genes are, for the first time, shown to be associated with bone resorption, and the results indicate that activated B cells produce BMP10. The study provides a rationale for a link between periodontal disease and other systemic diseases.