Heterogeneous origin of IgE in atopic dermatitis and psoriasis revealed by B cell receptor repertoire analysis

Chlorogenic acid alleviates DNCB-induced atopic dermatitis by inhibiting the Akt1/NF-κB signaling pathway

OBJECTIVE

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease that significantly impacts patients' quality of life. Chlorogenic acid (CGA), a polyphenol present in various dietary sources and plants, has been shown to reduce skin inflammation. However, its efficacy and mechanisms of action in AD have not been thoroughly investigated. This study aimed to evaluate the therapeutic effect of CGA on AD in mice and explored its mechanism.

METHODS

To establish a BALB/c mouse model of AD induced by 2,4-dinitrochlorobenzene (DNCB) to evaluate the therapeutic potential of CGA. The anti-inflammatory effects of CGA were assessed by measuring IL-1β and IL-6 levels in TNF-α-stimulated HaCaT cells. The phosphorylation levels of PI3K, Akt, Akt1, NF-κB, and IκB-α were analyzed using Western blotting. Molecular docking was conducted to evaluate the binding affinity of CGA to Akt1.

RESULTS

Topical application of CGA significantly reduced dermatitis scores, spleen index, epidermal thickness, mast cell infiltration, and skin fibrosis. CGA reversed DNCB-induced increases in IgE, histamine, TNF-α, IL-1β, IL-6, and IL-8 levels. Western blot analysis showed that CGA inhibited the PI3K/Akt and NF-κB signaling pathways. In vitro, CGA exerts its anti-inflammatory effects by inhibiting the Akt1/NF-κB pathway, and the Akt activator (SC79) can counteract this effect. Molecular docking and dynamics simulations suggest that CGA may inhibit Akt1 activity by interacting with specific residues (ALA-50, GLY-37, TYR-326, ASP-323).

CONCLUSIONS

CGA improves AD by inhibiting the Akt1/NF-κB pathway, suggesting its potential as a natural treatment for AD.

Treatment of pro-B acute lymphoblastic leukemia and severe plaque psoriasis with anti-CD19 CAR T cells: a case report

We report on a rare case of adult pro-B acute lymphoblastic leukemia (pro-B ALL) accompanied with severe refractory plaque psoriasis treated using autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy. An 18-year-old man with a known history of mild plaque psoriasis for 1 year was diagnosed with pro-B ALL. After induction chemotherapy, his psoriasis began to worsen. Extensive erythema and desquamation developed on the whole body, with severe plaque psoriasis on the knees and elbows, which did not respond to topical therapy. The application of CAR T-cell therapy not only enabled the patient to achieve deep complete remission (CR) but also allowed his skin lesions to completely subside. This successful treatment supports a potential pathogenic link between B cells and psoriasis, which could provide a new option for overcoming refractory psoriasis.

Immunoglobulin E, the potential accelerator of comorbid psoriasis and atherosclerosis

Immunoglobulin (Ig) E is a key mediator in the induction and maintenance of allergic inflammation, characterized by a Th2-dominated immune response. Recently epidemiological studies have showed that elevated serum total IgE levels or an increased abundance of mast cells (MCs) at the lesion site are observed in psoriatic patients with cardiovascular diseases (CVD), such as atherosclerosis. Although the underlying mechanisms by which IgE synergizing with MCs in promoting these chronic immune-inflammatory diseases remain unclear, the interleukin (IL)-23/IL-17 axis appears to play a crucial role in comorbidity of psoriasis and atherosclerosis. High IgE production may result from IL-17A response, further exacerbating inflammatory pathways involved in both psoriasis and atherosclerosis. This review explores the possible mechanisms of IgE in these comorbid conditions, reinforcing the rationale for IL-17A targeted biologics in the treatment of psoriasis and atherosclerosis comorbidity. Additionally, IgE is proposed as a potential therapeutic target for alleviating patients suffering from these comorbidity conditions.

IgG Signalling Involves in Skin Inflammation of Atopic Dermatitis

Atopic dermatitis (AD) patients usually have elevated serum IgE that is thought inducing inflammation upon binding to allergen. However, the role of IgE-producing B cells and other isotypes of immunoglobulin, such as IgG, in AD are not clear and rarely explored. This study aimed to investigate the role of IgE-producing B cells and other isotypes of immunoglobulin, particularly IgG, in skin lesion of AD. BCR repertoires were analysed using mRNA prepared from skin lesions and peripheral blood mononuclear cells (PBMCs) from AD patients and non-allergic healthy subjects. Single-cell RNA sequencing data of AD lesions from published literature were extracted to analyse the function of IgG. BCR repertoires from skin lesion and PBMCs clustered distinctly, and PBMCs showed higher interindividual similarity compared to those from the skin. The proportions of IGHM, IGHD, IGHA, IGHG and IGHE varied among skin lesion and PBMCs of AD patients and healthy individuals, and IGHG was significantly increased in AD lesion. IGHG showed biased VH usage, with dominance of V1-58, V1-8, V3-13 and V3-73. The much higher hyperexpanded clonality and lower diversity of IGHG repertoire in skin than those of the PBMCs, suggested the clonal expansion of IgG+ B cells in the skin. Pathways related with IgG activation were enriched in AD skin, and macrophages may be activated by IgG and promote skin inflammation. In conclusion, skin is not the main production site for IgE in AD. IgG may involve in promoting Th2 inflammation in AD skin through macrophages.

Distinct IgE sensitization profiles in chronic urticaria: a comparative study with classic allergic diseases

Introduction

Chronic urticaria (CU) is not traditionally classified as an allergic disease, but emerging evidence suggests a link to atopy. The quintessential marker of atopy is IgE sensitization, there is scarce information on the IgE sensitization characteristics of CU.

Methods

To investigate IgE sensitization characteristics in CU, and compare them with classic allergic diseases. We retrospectively analyzed the results of specific IgE (sIgE) and total IgE (tIgE) in CU patients, explored the distribution patterns of these atopic markers in CU, and compared these data with those of atopic dermatitis (AD), allergic rhinitis (AR), asthma (AS), and healthy controls (HC).

Results

1149 patients (396 CU, 411 AD, 101 AR, 139 AS and 102 HC) were included in the study. 33.1% of CU patients showed positive sIgE and 49.0 % had elevated tIgE levels, significantly higher than those in HC. Comparative analysis with classic allergic diseases showed CU patients had a lower sIgE positivity rate but no significant difference in tIgE levels. Gender and age influenced sensitization profiles, with male CU patients showing a higher sIgE positivity rate. The distribution of sIgE levels, allergen categories, and tIgE elevated levels range in CU differed from classic allergic disease. The concordance rate between sIgE and tIgE results in CU was lower than in classic allergic disease.

Conclusion

Our study reveals that a significant proportion of CU patients display IgE sensitization, suggesting a clear atopic background compared to the general population. However, the IgE sensitization profile in CU differs from that of classical allergic diseases such as AD, AR, and AS, characterized by relatively lower intensity of IgE sensitization. The underlying reasons for this phenomenon and its clinical implications in CU warrant further research.

Estimating the Number of Polygenic Diseases Among Six Mutually Exclusive Entities of Non-Tumors and Cancer

In the era of precision medicine with increasing amounts of sequenced cancer and non-cancer genomes of different ancestries, we here enumerate the resulting polygenic disease entities. Based on the cell number status, we first identified six fundamental types of polygenic illnesses, five of which are non-cancerous. Like complex, non-tumor disorders, neoplasms normally carry alterations in multiple genes, including in 'Drivers' and 'Passengers'. However, tumors also lack certain genetic alterations/epigenetic changes, recently named 'Goners', which are toxic for the neoplasm and potentially constitute therapeutic targets. Drivers are considered essential for malignant transformation, whereas environmental influences vary considerably among both types of polygenic diseases. For each form, hyper-rare disorders, defined as affecting <1/108 individuals, likely represent the largest number of disease entities. Loss of redundant tumor-suppressor genes exemplifies such a profoundly rare mutational event. For non-tumor, polygenic diseases, pathway-centered taxonomies seem preferable. This classification is not readily feasible in cancer, but the inclusion of Drivers and possibly also of epigenetic changes to the existing nomenclature might serve as initial steps in this direction. Based on the detailed genetic alterations, the number of polygenic diseases is essentially countless, but different forms of nosologies may be used to restrict the number.

B Cells Infiltration Potentially Responded Better to Systemic Corticoids in Oral Lichen Planus and Oral Lichenoid Lesions

Oral lichen planus (OLP) and oral lichenoid lesion (OLL) are chronic inflammatory diseases involving the oral mucosa. B cells infiltration in OLP and OLL, however, little is known about these cells in OLP and OLL. To analyze the function and infiltrating features of B lymphocytes in OLP and OLL, and to preliminarily evaluate their correlation with clinical outcomes. Tissue samples were collected from OLP, OLL, and healthy mucosa. The phenotypes and amounts of B cells in tissues were analyzed by single-cell sequencing. Their proportion and infiltrating features in tissues were examined by immunohistochemistry and immunofluorescence. With the systemic medication of corticoids, the correlation between B cells infiltrating characteristics and the clinical outcomes were evaluated. A quantified proportion increase of B cells was shown in both OLP and OLL. B cells in OLP demonstrated heightened activation and enhanced regulation in immune response. A cohort of 100 patients with OLP/OLL and 13 healthy controls were examined to investigate the B cells infiltration pattern. B cells were distributed in the superficial layer of lamina propria in 92.9% and 41.9% of OLP and OLL, respectively(P < 0.01); focally distributed in 25.0% and 62.9% of OLP and OLL, respectively(P < 0.01). With the systemic medication of corticoids, the cases with B cell infiltration (B+) in OLP and OLL groups showed a statistically significant reduction in REU scores before and after treatment (P < 0.01). B cells are widely present in OLP and OLL, and B cell infiltration in OLP and OLL are related to the better therapeutic effect of oral corticoids.

The origins and longevity of IgE responses as indicated by serological and cellular studies in mice and humans

The existence of long-lived IgE antibody-secreting cells (ASC) is contentious, with the maintenance of sensitization by the continuous differentiation of short-lived IgE+ ASC a possibility. Here, we review the epidemiological profile of IgE production, and give an overview of recent discoveries made on the mechanisms regulating IgE production from mouse models. Together, these data suggest that for most individuals, in most IgE-associated diseases, IgE+ ASC are largely short-lived cells. A subpopulation of IgE+ ASC in humans is likely to survive for tens of months, although due to autonomous IgE B cell receptor (BCR) signaling and antigen-driven IgE+ ASC apoptosis, in general IgE+ ASC probably do not persist for the decades that other ASC are inferred to do. We also report on recently identified memory B cell transcriptional subtypes that are the likely source of IgE in ongoing responses, highlighting the probable importance of IL-4Rα in their regulation. We suggest the field should look at dupilumab and other drugs that prohibit IgE+ ASC production as being effective treatments for IgE-mediated aspects of disease in most individuals.

Histone and Histone Acetylation-Related Alterations of Gene Expression in Uninvolved Psoriatic Skin and Their Effects on Cell Proliferation, Differentiation, and Immune Responses

Psoriasis is a chronic immune-mediated skin disease in which the symptom-free, uninvolved skin carries alterations in gene expression, serving as a basis for lesion formation. Histones and histone acetylation-related processes are key regulators of gene expression, controlling cell proliferation and immune responses. Dysregulation of these processes is likely to play an important role in the pathogenesis of psoriasis. To gain a complete overview of these potential alterations, we performed a meta-analysis of a psoriatic uninvolved skin dataset containing differentially expressed transcripts from nearly 300 individuals and screened for histones and histone acetylation-related molecules. We identified altered expression of the replication-dependent histones HIST2H2AA3 and HIST2H4A and the replication-independent histones H2AFY, H2AFZ, and H3F3A/B. Eight histone chaperones were also identified. Among the histone acetyltransferases, ELP3 and KAT5 and members of the ATAC, NSL, and SAGA acetyltransferase complexes are affected in uninvolved skin. Histone deacetylation-related alterations were found to affect eight HDACs and members of the NCOR/SMRT, NURD, SIN3, and SHIP HDAC complexes. In this article, we discuss how histone and histone acetylation-related expression changes may affect proliferation and differentiation, as well as innate, macrophage-mediated, and T cell-mediated pro- and anti-inflammatory responses, which are known to play a central role in the development of psoriasis.

Human Mast Cells Upregulate Cathepsin B, a Novel Marker of Itch in Psoriasis

Mast cells (MCs) contribute to skin inflammation. In psoriasis, the activation of cutaneous neuroimmune networks commonly leads to itch. To dissect the unique contribution of MCs to the cutaneous neuroinflammatory response in psoriasis, we examined their density, distribution, relation to nerve fibres and disease severity, and molecular signature by comparing RNA-seq analysis of MCs isolated from the skin of psoriasis patients and healthy volunteers. In involved psoriasis skin, MCs and Calcitonin Gene-Related Peptide (CGRP)-positive nerve fibres were spatially associated, and the increase of both MC and nerve fibre density correlated with disease severity. Gene set enrichment analysis of differentially expressed genes in involved psoriasis skin showed significant representation of neuron-related pathways (i.e., regulation of neuron projection along with dendrite and dendritic spine morphogenesis), indicating MC engagement in neuronal development and supporting the evidence of close MC-nerve fibre interaction. Furthermore, the analysis of 208 identified itch-associated genes revealed that CTSB, TLR4, and TACR1 were upregulated in MCs in involved skin. In both whole-skin published datasets and isolated MCs, CTSB was found to be a reliable indicator of the psoriasis condition. Furthermore, cathepsin B+ cells were increased in psoriasis skin and cathepsin B+ MC density correlated with disease severity. Therefore, our study provides evidence that cathepsin B could serve as a common indicator of the MC-dependent itch signature in psoriasis.

Burden of Disease; the Current Status of the Diagnosis and Management of Atopic Dermatitis in China

Atopic dermatitis (AD) is now a global health problem and has been attracting extensive attention from both academic and public society in China. This review aimed to present the current status of the prevalence, disease burden, clinical features, diagnosis, and management of AD in China. The prevalence of AD has been increasing rapidly in China during the past decades, partially due to the increased recognition of the disease; there are still substantial amounts of over-diagnosed eczema and under-diagnosed AD. Chinese dermatologists see many AD patients with atypical manifestation, which poses a challenge to the diagnosis. The Chinese diagnostic criteria for adults and pediatric patients with AD have been proposed respectively and validated with high sensitivity and specificity. International and Chinese guidelines for management of AD have been popularized; however, there are still many practices that need verification through randomized case-control study. Dupilumab and JAK inhibitors have demonstrated favorable efficacy for AD patients in China, and a multidimensional approach is needed for selection of the patients and evaluation of the efficacy and safety. Patient education and long-term management for AD are just beginning in China, and need to be strengthened in the future.

Mast cells as important regulators in the development of psoriasis

Psoriasis is a chronic inflammatory immune skin disease mediated by genetic and environmental factors. As a bridge between innate and adaptive immunity, mast cells are involved in the initiation, development, and maintenance of psoriasis by interactions and communication with a variety of cells. The current review describes interactions of mast cells with T cells, Tregs, keratinocytes, adipocytes, and sensory neurons in psoriasis to emphasize the important role of mast cell-centered cell networks in psoriasis.

Elevation of IgE in patients with psoriasis: Is it a paradoxical phenomenon?

Immunoglobulin E (IgE) elevation is a hallmark of allergic conditions such as atopic dermatitis (AD). The pathogenesis of AD is typically associated with high levels of IL-4 and IL-13 produced by activated T helper 2 (Th2) cells. Psoriasis, on the other hand, is an inflammatory skin disease mainly driven by Th17 cells and their related cytokines. Although the immunopathologic reactions and clinical manifestations are often easily distinguished in the two skin conditions, patients with psoriasis may sometimes exhibit AD-like manifestations, such as elevated IgE and persistent pruritic lesions. Given the fact that the effective T cells have great plasticity to re-differentiate in response to innate and environmental factors, this unusual skin condition could be a consequence of a cross-reaction between distinct arms of T-cell and humoral immunity. Here we review the literature concerning the roles of IgE in the development of AD and psoriasis, showing that elevated IgE seems to be an important indicator for this non-typical psoriasis.

The Immunological and Allergen Profiles of Patients with Atopic Dermatitis or Psoriasis

Background and objectives: Atopic dermatitis (AD) and psoriasis (PS) are systemic inflammatory diseases with complex and distinct immune mechanisms. That the same factors may aggravate both diseases cannot be ruled out. The aim of this study was to assess the potential differences between a sensitization to inhaled allergens and the immunological profiles of patients diagnosed with AD and PS in comparison with healthy controls. Materials and methods: A total of 139 patients with AD, 115 with PS, and 142 controls were included in the prospective study. Patients were eligible if they were diagnosed with mild to severe AD or PS and between 18 and 65 years of age. In all the participants, the serum concentrations of specific IgE (sIgE) for common inhaled allergens were measured. In all the subjects, the cytokine serum blood profiles for TNF-α, IFN-γ, Il-2, Il-4, Il-5, Il-6, Il-8, Il-12, Il-17, Il-18, Il-22, and Il-24 were measured via an ELISA. Results: The patients with AD had positive sIgE results more frequently than the patients with PS and the controls (113 vs. 36 vs. 21, respectively). A sensitization to mites was dominant in the patients with AD (p < 0.05), and a sensitization to Aspergillus was dominant in the patients with PS (p < 0.05). The patients with multiple allergies to inhaled allergens had a lower risk of developing PS (OR = 0.65; 95% CI: 0.43−0.86) but a greater risk of severe AD (OR = 3.77; 95% CI: 3.25−3.96). The mean concentrations of the most tested cytokines were comparable in the patients with AD and PS. However, high serum concentrations of Il-4, Il-5, and Il-6 were only dominant in the AD group. There were no relationships between the increased serum concentrations of individual cytokines and allergies to the individually examined allergens. Conclusion: Inhalation-dependent IgE sensitizations were prevalent in the AD patients but were also possible in the PS patients; they were often without clinical manifestations in the latter group. The investigated cytokine profiles indicated their high convergence in the studied patients and confirmed the active inflammatory nature of AD and PS.

B-cell receptor physical properties affect relative IgG1 and IgE responses in mouse egg allergy

Mutated and unmutated IgE and IgG play different and partly opposing roles in allergy development, but the mechanisms controlling their relative production are incompletely understood. Here, we analyzed the IgE-response in murine food allergy. Deep sequencing of the complementary-determining region (CDR) repertoires indicated that an ongoing unmutated extrafollicular IgE response coexists with a germinal center response, even after long-lasting allergen challenges. Despite overall IgG1-dominance, a significant proportion of clonotypes contained several-fold more IgE than IgG1. Clonotypes with differential bias to either IgE or IgG1 showed distinct hypermutation and clonal expansion. Hypermutation rates were associated with different physiochemical binding properties of individual B-cell receptors (BCR). Increasing BCR signaling strength inhibited class switching from IgG1 to IgE in vitro, preferentially constraining IgE formation. These data indicate that antigen-binding properties of individual BCRs determine differential IgE hypermutation and IgE versus IgG1 production on the level of single B-cell clones.