Baseline IL-22 expression in patients with atopic dermatitis stratifies tissue responses to fezakinumab

TGFβ1 mimetic peptide modulates immune response to grass pollen allergens in mice

BACKGROUND

Transforming growth factor β1 (TGFβ1) is a cytokine that exerts immunosuppressive functions, as reflected by its ability to induce regulatory T (Treg) cell differentiation and inhibit Th1 and Th2 responses. Hence, peptides that mimic the active core domain of TGFβ1 may be promising candidates for modulation of the allergic response. This study aimed to investigate a synthetic TGFβ1 mimetic peptide (TGFβ1-mim) for its ability to modulate the immune response during allergic sensitization to grass pollen allergens.

METHODS

The in vitro action of TGFβ1-mim was evaluated in human lung epithelial cells, Jurkat cells, and rat basophilic leukemia cells. The in vivo action was evaluated in a murine model of Phl p 5 allergic sensitization. Additionally, the Th2 modulatory response was evaluated in IL-4 reporter mice.

RESULTS

In vitro, TGFβ1-mim downregulated TNF-α production, IL-8 gene expression, and cytokine secretion, upregulated IL-10 secretion, and inhibited Phl p 5-induced basophil degranulation. During Phl p 5 sensitization in mice, TGFβ1-mim downregulated IL-2, IL-4, IL-5, IL-13, and IFN-γ, upregulated IL-10, and induced Treg cell production. Furthermore, mice treated with TGFβ1-mim had lower levels of IgE, IgG1, IgG2a and higher levels of IgA antibodies than control mice. In a reporter mouse, the mimetic inhibited Th2 polarization.

CONCLUSION

The TGFβ1-mim efficiently modulated various important events that exacerbate the allergic microenvironment, including the production of main cytokines that promote Th1 and Th2 differentiation, and the induction of allergen-specific regulatory T cells, highlighting its potential use in therapeutic approaches to modulate the immune response toward environmental allergens.

The role of IL-22 in intestinal health and disease

The cytokine interleukin-22 (IL-22) is a critical regulator of epithelial homeostasis. It has been implicated in multiple aspects of epithelial barrier function, including regulation of epithelial cell growth and permeability, production of mucus and antimicrobial proteins (AMPs), and complement production. In this review, we focus specifically on the role of IL-22 in the intestinal epithelium. We summarize recent advances in our understanding of how IL-22 regulates homeostasis and host defense, and we discuss the IL-22 pathway as a therapeutic target in diseases of the intestine, including inflammatory bowel disease (IBD), graft-versus-host disease (GVHD), and cancer.

New biological treatments for asthma and skin allergies

Allergies are typically endemic, complex and heterogeneous diseases with a high impact at quality of life. Mechanistically, type 2 immune responses involving eosinophil and basophil granulocytes, mast cells and humoral factors such as IgE are key drivers of allergic diseases. Fighting allergic diseases knows three strategies: prevention, symptomatic and causative therapy. While remarkable progress was made in understanding molecular events in allergies as a prerequisite for effective prevention and desensitization, this review article focuses on the most efficient symptomatic treatments-that is using more and more specific antibodies neutralizing particular immune pathways. We highlight and classify recent and upcoming developments in the three prototype chronic allergic diseases allergic asthma, chronic spontaneous urticaria and atopic eczema. In all three examples, biologics such as dupilumab or omalizumab become reliable and efficient therapeutic options. Finally, we give an outlook how a diagnostic and therapeutic workflow might look like in the near future for these three major burdens of society.

The Role of Th17-Related Cytokines in Atopic Dermatitis

T helper-17 (Th17) cells, which mainly produce IL-17, are associated with development of various autoimmune diseases such as rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis, and psoriasis. IL-17 and related cytokines are therapeutic targets of these diseases. In atopic dermatitis (AD), Th2 cytokines such as IL-4 and IL-13 are regarded to be the main player of the disease; however, Th17 cytokines are also expressed in AD skin lesions. Expression of IL-22 rather than IL-17 is predominant in AD skin, which is contrary to cytokine expression in psoriasis skin. Relatively low IL-17 expression in AD skin can induce relatively low antimicrobial peptide expression, which may be a reason why bacterial infection is frequently seen in AD patients. Failure of clinical trials for investigating the efficacy of anti-IL-12/23 p40 in AD has suggested that IL-17 expressed in skin lesions should not be the main player but a bystander responding to barrier dysfunction.

Intratumoral IL22-producing cells define immunoevasive subtype muscle-invasive bladder cancer with poor prognosis and superior nivolumab responses

Our previous researches have identified immunoevasive subtype muscle-invasive bladder cancer (MIBC) characterized with immune cells infiltration patterns. Our study explored the clinical significance, immunoregulatory role and therapeutic value of intratumoral IL22-producing cells in MIBC. Two hundred and fifty-nine formalin-fixed paraffin-embedded MIBC samples and 83 freshly resected MIBC tissues and 391 TCGA MIBC samples were retrospectively evaluated. Immunohistochemistry and flow cytometry were applied to identify immune cell infiltration and functional status. In vitro intervention studies were to test the therapeutic and predictive potential of IL22+ cells. Our data revealed patients with high IL22+ cells infiltration suffered poor overall survival and recurrence-free survival in both training and validation cohorts. Only pT2 patients of combined cohort with low IL22+ cells infiltration gained survival benefits from adjuvant chemotherapy (ACT) significantly. Besides, immune contexture featured with increased pro-tumor cells and immunosuppressive cytokines was identified in patients with high IL22+ cells density. The expression pattern of exhausted and effector markers in CD8+ T cells from high IL22+ cells subgroup indicated their dysfunctional status. Importantly, nivolumab showed tumor-killing efficacy in tumors with high IL22+ cells infiltration, and immunosuppressive contexture with CD8+ T cells exhaustion was abrogated in tumors treated with anti-IL22 antibody. In summary, IL22+ cells infiltration determined immunosuppressive contexture with CD8+ T cell dysfunction. Tumor-infiltrating IL22+ cells could be used as an independent marker to predict prognosis and ACT responses. IL22+ cells infiltration possessed the potential to be a favorable predictor for nivolumab application and IL22 blockade could be a novel therapeutic strategy in MIBC.

Progression of acute-to-chronic atopic dermatitis is associated with quantitative rather than qualitative changes in cytokine responses

BACKGROUND

Although multiple studies have assessed molecular changes in chronic atopic dermatitis (AD) lesions, little is known about the transition from acute to chronic disease stages, and the factors and mechanisms that shape chronic inflammatory activity.

OBJECTIVES

We sought to assess the global transcriptome changes that characterize the progression from acute to chronic stages of AD.

METHODS

We analyzed transcriptome changes in paired nonlesional skin, acute and chronic AD lesions from 11 patients and 38 healthy controls by RNA-sequencing, and conducted in vivo and histological assays to evaluate findings.

RESULTS

Our data demonstrate that approximately 74% of the genes dysregulated in acute lesions remain or are further dysregulated in chronic lesions, whereas only 34% of the genes dysregulated in chronic lesions are altered already in the acute stage. Nonlesional AD skin exhibited enrichment of TNF, T_H1, T_H2, and T_H17 response genes. Acute lesions showed marked dendritic-cell signatures and a prominent enrichment of T_H1, T_H2, and T_H17 responses, along with increased IL-36 and thymic stromal lymphopoietin expression, which were further heightened in chronic lesions. In addition, genes involved in skin barrier repair, keratinocyte proliferation, wound healing, and negative regulation of T-cell activation showed a significant dysregulation in the chronic versus acute comparison. Furthermore, our data show progressive changes in vasculature and maturation of dendritic-cell subsets with chronicity, with FOXK1 acting as immune regulator.

CONCLUSIONS

Our results show that the changes accompanying the transition from nonlesional to acute to chronic inflammation in AD are quantitative rather than qualitative, with chronic AD having heightened T_H2, T_H1, T_H17, and IL36 responses and skin barrier repair mechanisms. These findings provide novel insights and highlight underappreciated pathways in AD pathogenesis that may be amenable to therapeutic targeting.

New treatments for atopic dermatitis targeting beyond IL-4/IL-13 cytokines

OBJECTIVE

Atopic dermatitis (AD) is an increasingly common inflammatory skin disease undergoing significant revolution in recent years. New data on disease pathogenesis advanced the developments of novel therapeutics, mainly for patients with moderate to severe conditions, for whom treatment options have been largely insufficient for many years.

DATA SOURCES

Review of recent studies investigating systemic treatments for AD.

STUDY SELECTIONS

Relevant literature concerning novel therapeutics for AD beyond targeted monoclonal antibodies antagonizing selectively interleukin (IL)-4 or IL-13 was obtained from a PubMed and clinicaltrials.gov search and summarized.

RESULTS

Multiple clinical trials of both nonspecific as well as specific agents revealed favorable outcomes in AD, including JAK inhibitors, a dual JAK/SYK inhibitor, a histamine H4R antagonist, antagonists of the TSLP/OX40L axis, an IL-22 inhibitor, and IL-33 and IL-17C antagonists. Importantly, negative trials were published as well (eg, phosphodiesterase 4 inhibitor, apremilast).

CONCLUSION

In this rapidly evolving field of AD treatments, a completely new treatment paradigm will be available in the near future.

[Molecular diagnostics of hand eczema]

BACKGROUND

Using current diagnostic tools for hand eczema, namely clinical picture and histology, differential diagnoses such as psoriasis palmaris usually cannot be ruled out.

OBJECTIVES

Discussion of current diagnostic possibilities for hand eczema; presentation and critical evaluation of proposed biomarkers for molecular diagnostics and outlook how diagnostics in dermatology will change in the near future.

MATERIALS AND METHODS

In this article, we discuss basic research and provide a review of the literature.

RESULTS

Molecular diagnostics has the potential to substantially improve diagnosis of hand eczema; prerequisites are prospective validation of proposed markers and availability of valid and cost-effective diagnostics.

CONCLUSIONS

In the near future, the diagnosis of hand eczema will be complemented by software algorithms and artificial intelligence on the one hand and simple, precise, and economic molecular diagnostic devices on the other.

[Atopic eczema and microbiome]

BACKGROUND

Atopic eczema is a chronic inflammatory skin disease characterized by skin barrier disruption, inflammation and dysbiosis. Furthermore, atopic eczema is associated with other diseases of the atopic group, such as allergies, rhinoconjunctivitis and asthma. The skin microbiome consists of bacteria, viruses and fungi. Patients suffering from atopic eczema often show an imbalance (dysbiosis) of the microbiome.

OBJECTIVE

It is not yet completely clarified what influence dysbiosis and the cutaneous microbiome have on the development and severity of atopic eczema. Modern sequencing methods will be used to investigate the role of the skin microbiome in the pathogenesis of atopic eczema in the future.

MATERIAL AND METHODS

This article presents and discusses the results of current basic research.

RESULTS

The human skin microbiome differs according to body region, age and gender. It interacts with the skin barrier and the cutaneous immune system. Patients suffering from atopic eczema develop dysbiosis consisting of an increased load of Staphylococcus aureus and a reduction of commensal skin bacteria. The altered skin microbiome in patients suffering from atopic eczema may also affect skin barrier function and inflammatory reactions.

CONCLUSION

Knowledge of the skin microbiome has improved in recent years. This will certainly improve the understanding of the pathogenesis causing atopic eczema. These findings may also form the foundation of new treatment and prevention strategies for atopic eczema in the future.

New and Emerging Therapies for Pediatric Atopic Dermatitis

Atopic dermatitis (AD) is a chronic, inflammatory skin disease characterized by pruritus, inflammatory erythematous skin lesions, and skin-barrier defect. Current mainstay treatments of emollients, steroids, calcineurin inhibitors, and immunosuppressants have limited efficacy and potentially serious side effects. Recent advances and understanding of the pathogenesis of AD have resulted in new therapies that target specific pathways with increased efficacy and the potential for less systemic side effects. New FDA-approved therapies for AD are crisaborole and dupilumab. The JAK-STAT inhibitors (baricitinib, upadacitinib, PF-04965842, ASN002, tofacitinib, ruxolitinib, and delgocitinib) have the most promising results of the emerging therapies. Other drugs with potential include the aryl hydrocarbon receptor modulating agent tapinarof, the IL-4/IL-13 antagonists lebrikizumab and tralokinumab, and the IL-31Rα antagonist nemolizumab. In this review, new and emerging AD therapies will be discussed along with their mechanisms of action and their potential based on clinical study data.

Understanding the immune landscape in atopic dermatitis: The era of biologics and emerging therapeutic approaches

Atopic dermatitis (AD) is a chronic, systemic, inflammatory disease that affects the skin and is characterized by persistent itch and marked redness. AD is associated with an increased risk of skin infections and a reduced quality of life. Most AD treatment options to date were not designed to selectively target disease-causing pathways that have been established for this indication. Topical therapies have limited efficacy in moderate-to-severe disease, and systemic agents such as corticosteroids and immunosuppressants present with tolerability issues. Advances in the understanding of AD pathobiology have made possible a new generation of more disease-specific AD therapies. AD is characterized by the inappropriate activation of type 2 T helper (Th2) cells and type 2 innate lymphoid (ILC2) cells, with a predominant increase in type 2 cytokines in the skin, including interleukin (IL)-13 and IL-4. Both cytokines are implicated in tissue inflammation and epidermal barrier dysfunction, and monoclonal antibodies targeting each of these interleukins or their receptors are in clinical development in AD. In March 2017, dupilumab, a human anti-IL-4Rα antibody, became the first biologic to receive approval in the United States for the treatment of moderate-to-severe AD. The anti-IL-13 monoclonal antibodies lebrikizumab and tralokinumab, which bind different IL-13 epitopes with potentially different effects, are currently in advanced-stage trials. Here, we briefly review the underlying pathobiology of AD, the scientific basis for current AD targets, and summarize current clinical studies of these agents, including new research to develop both predictive and response biomarkers to further advance AD therapy in the era of precision medicine.

Personalized medicine-concepts, technologies, and applications in inflammatory skin diseases

The current state, tools, and applications of personalized medicine with special emphasis on inflammatory skin diseases like psoriasis and atopic dermatitis are discussed. Inflammatory pathways are outlined as well as potential targets for monoclonal antibodies and small-molecule inhibitors.

Racial differences in atopic dermatitis

OBJECTIVE

To summarize studies investigating ethnical and racial differences in atopic dermatitis (AD) epidemiology, clinical features, and skin and blood phenotypes.

DATA SOURCES

PubMed literature review (years 2000-2018).

STUDY SELECTIONS

Articles discussing primarily human disease.

RESULTS

Higher overall rates of AD were found in Africa and Oceania as opposed to India and Northern and Eastern Europe. In the United States, AD prevalence was found to be higher in African American (19.3%) compared with European American (16.1%) children. Although several studies have consistently found FLG loss-of-function mutations in up to 50% of European and 27% of Asian patients with AD, FLG mutations were 6 times less common in African American than in European American patients, even in patients with severe AD. Thus, FLG mutations seem to play less a pathogenic role in patients of African origin than in individuals of European or Asian ancestry. The immune phenotype of all ethnic groups was characterized by strong TH2 activation, but important differences in immune polarization exist among the different ethnicities. Asian patients with AD had stronger TH17/TH22 activation than African American and European American patients with AD, whereas African American patients had the highest serum IgE levels among all groups, while largely lacking TH1 and TH17 activation.

CONCLUSION

AD is a heterogeneous disease that has differences among various ethnic and racial groups, which might be important for the development of future, targeted treatments and for personalized medicine approaches.

Treatment-resistant atopic dermatitis: challenges and solutions

Atopic dermatitis (AD) is a common, chronic, relapsing-remitting inflammatory disease that can be challenging to treat. Patients with mild disease are usually managed well with good skin care practices including moisturization and appropriate bathing along with intermittent use of topical therapies such as topical corticosteroids and/or topical calcineurin inhibitors during flares. Patients with frequent flares may benefit from proactive application of topical therapies twice a week to the most troublesome areas. Patients with severe disease often present significant treatment challenges. Systemic therapies are usually required for severe AD but have varying degrees of success and can be associated with side-effect profiles that require counseling and close monitoring. Phototherapy has been shown to have success in treating moderate-to-severe AD, but several factors can limit its utility and efficacy including cost and access. New therapies are in development targeting specific pathways relevant for AD. Dupilumab was the first biologic treatment approved in North America, Europe, and Japan for adults with moderate-to-severe AD. Although this treatment can lead to rapid improvement in the majority of patients, there are inadequate responders. In this review, we discuss the clinical challenges and treatment options for moderate-to-severe refractory AD.

GBR 830, an anti-OX40, improves skin gene signatures and clinical scores in patients with atopic dermatitis

BACKGROUND

GBR 830 is a humanized mAb against OX40, a costimulatory receptor on activated T cells. OX40 inhibition might have a therapeutic role in T cell-mediated diseases, including atopic dermatitis (AD).

OBJECTIVE

This exploratory phase 2a study investigated the safety, efficacy, and tissue effects of GBR 830 in patients with AD.

METHODS

Patients with moderate-to-severe AD (affected body surface area, ≥10%; Eczema Area and Severity Index score, ≥12; and inadequate response to topical treatments) were randomized 3:1 to 10 mg/kg intravenous GBR 830 or placebo on day 1 (baseline) and day 29. Biopsy specimens were collected (n = 40) at days 1, 29, and 71. Primary end points included treatment-emergent adverse events (TEAEs) and changes from baseline in biomarkers (epidermal hyperplasia/cytokines) at days 29 and 71.

RESULTS

GBR 830 was well tolerated, with equal TEAE distribution (GBR 830, 63.0% [29/46]; placebo, 63.0% [10/16]). One serious TEAE in the GBR 830 group was deemed unrelated to study drug. At day 71, the proportion of intent-to-treat subjects achieving 50% or greater improvement in Eczema Area and Severity Index score was greater with GBR 830 (76.9% [20/26]) versus placebo (37.5% [3/8]). GBR 830 induced significant progressive reductions in T_H1 (IFN-γ/CXCL10), T_H2 (IL-31/CCL11/CCL17), and T_H17/T_H22 (IL-23p19/IL-8/S100A12) mRNA expression in lesional skin. Significant progressive reductions until day 71 in the drug group were seen in OX40⁺ T cells and OX40L⁺ dendritic cells (P < .001). Hyperplasia measures (thickness/keratin 16/Ki67) showed greater reductions with GBR 830 (P < .001).

CONCLUSIONS

Two doses of GBR 830 administered 4 weeks apart were well tolerated and induced significant progressive tissue and clinical changes until day 71 (42 days after the last dose), highlighting the potential of OX40 targeting in patients with AD.

From Bench to Clinic: the Potential of Therapeutic Targeting of the IL-22 Signaling Pathway in Atopic Dermatitis

Atopic dermatitis (AD) is the most common pruritic inflammatory skin disease characterized by thickening of epidermis and dermis as well as by the infiltration of multiple pathogenic polarized T lymphocytes, including Th2, Th17, and Th22 cells. Significant progress has been made to develop targeted therapeutics for treating AD, e.g., Food and Drug Administration-approved dupilumab, an antibody for dual targeting of IL-4 and IL-13 signaling pathways. Additionally, a growing body of published evidence and a promising result from the early stage of the clinical trial with ILV-094, an anti-IL-22 antibody, strongly support the notion that IL-22 is a potential therapeutic target for treating AD. Moreover, we also experimentally proved that IL-22 contributes to the pathophysiology of AD by employing a murine model of AD induced by epicutaneous sensitization. Here, we review recent preclinical and clinical findings that have advanced our understanding of the roles of IL-22 and Th22 cells in skin inflammation. We conclude that blockade of IL-22 signaling may be a promising therapeutic approach for the treatment of AD.