Immune monitoring for precision medicine in allergy and asthma

Zebrafish Is a Powerful Tool for Precision Medicine Approaches to Neurological Disorders

Personalized medicine is currently one of the most promising tools which give hope to patients with no suitable or no available treatment. Patient-specific approaches are particularly needed for common diseases with a broad phenotypic spectrum as well as for rare and yet-undiagnosed disorders. In both cases, there is a need to understand the underlying mechanisms and how to counteract them. Even though, during recent years, we have been observing the blossom of novel therapeutic techniques, there is still a gap to fill between bench and bedside in a patient-specific fashion. In particular, the complexity of genotype-to-phenotype correlations in the context of neurological disorders has dampened the development of successful disease-modifying therapeutics. Animal modeling of human diseases is instrumental in the development of therapies. Currently, zebrafish has emerged as a powerful and convenient model organism for modeling and investigating various neurological disorders. This model has been broadly described as a valuable tool for understanding developmental processes and disease mechanisms, behavioral studies, toxicity, and drug screening. The translatability of findings obtained from zebrafish studies and the broad prospect of human disease modeling paves the way for developing tailored therapeutic strategies. In this review, we will discuss the predictive power of zebrafish in the discovery of novel, precise therapeutic approaches in neurosciences. We will shed light on the advantages and abilities of this in vivo model to develop tailored medicinal strategies. We will also investigate the newest accomplishments and current challenges in the field and future perspectives.

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

BACKGROUND

Epicutaneous sensitization is an important route for the production of IgE, and skin inflammation-induced IgE has recently been reported having features of natural antibody. Atopic dermatitis (AD) and psoriasis have differentially increased level of serum IgE; however, the production mechanism of IgE in these inflammatory skin diseases remains unknown.

OBJECTIVE

To explore the origin of IgE in AD and psoriasis by analyzing the B cell receptor repertoire.

METHODS

mRNA was prepared from peripheral blood mononuclear cells of AD and psoriasis patients that had elevated serum levels of IgE, and immunoglobulin heavy chain (IGH) repertoires were sequenced after reverse transcription. Clonal lineages of B cells containing members expressing IgE were identified, and somatic hypermutations in IGH inherited from common ancestors within the clonal lineage were used to infer the relationships between B cells.

RESULTS

The proportions of IGHE from AD and psoriasis were higher than that of normal control, which were positively correlated with the levels of serum total IgE. The somatic hypermutation value of IGHE variable region was lower than that of IGHG and IGHA, but higher than IGHM and IGHD, indicating a mixed natural and adaptive origins of IgE; and psoriasis demonstrated lower level of hypermutation than AD. The Shannon indexes of CDR3 in IGHE of AD and psoriasis were higher than that of normal control, also supporting the natural origin. The VH usage of IgE was weakly biased in AD and psoriasis patients with high level of house dust mite-specific IgE. Comparison of the number of shared mutations in multi-isotype lineages containing IgE showed that isotype-switching from IgG-expressing B cells might be the major source of IgE in AD and psoriasis.

CONCLUSION

IgE has heterogeneous origin in AD and psoriasis, and skin inflammation may contribute to the increased production of natural IgE.

Advances and novel developments in mechanisms of allergic inflammation

In the past decade, research in the molecular and cellular underpinnings of basic and clinical immunology has significantly advanced our understanding of allergic disorders, allowing scientists and clinicians to diagnose and treat disorders such as asthma, allergic and nonallergic rhinitis, and food allergy. In this review, we discuss several significant recent developments in basic and clinical research as well as important future research directions in allergic inflammation. Certain key regulatory cytokines, genes and molecules have recently been shown to play key roles in allergic disorders. For example, interleukin-33 (IL-33) plays an important role in refractory disorders such as asthma, allergic rhinitis and food allergy, mainly by inducing T helper (Th) 2 immune responses and clinical trials with IL-33 inhibitors are underway in food allergy. We discuss interleukin 4 receptor pathways, which recently have been shown to play a critical role among the allergic inflammatory pathways that drive allergic disorders and pathogenesis. Further, the cytokine thymic stromal lymphopoietin (TSLP) has recently been shown as a factor in maintaining immune homeostasis and regulating type 2 inflammatory responses at mucosal barriers in allergic inflammation and targeting TSLP-mediated signalling is considered an attractive therapeutic strategy. In addition, new findings establish an important T cell-intrinsic role of mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) proteolytic activity in the suppression of autoimmune responses. We have seen how mutations in the filaggrin gene are a significant risk factor for allergic diseases such as atopic dermatitis, asthma, allergic rhinitis, food allergy, contact allergy, and hand eczema. We are only beginning to understand the mechanisms by which the human microbiota may be regulating the immune system, and how sudden changes in the composition of the microbiota may have profound effects, linked with an increased risk of developing chronic inflammatory disorders, including allergies. New research has shown the important but complex role monocytes play in disorders such as food allergies. Finally, we discuss some of the new directions of research in this area, particularly the important use of biologicals in oral immunotherapy, advances in gene therapy, multifood therapy, novel diagnostics in diagnosing allergic disorders and the central role that omics play in creating molecular signatures and biomarkers of allergic disorders such as food allergy. Such exciting new developments and advances have significantly moved forth our ability to understand the mechanisms underlying allergic diseases for improved patient care.

Allergome-wide peptide microarrays enable epitope deconvolution in allergen-specific immunotherapy

BACKGROUND

The interaction of allergens and allergen-specific IgE initiates the allergic cascade after crosslinking of receptors on effector cells. Antibodies of other isotypes may modulate such a reaction. Receptor crosslinking requires binding of antibodies to multiple epitopes on the allergen. Limited information is available on the complexity of the epitope structure of most allergens.

OBJECTIVES

We sought to allow description of the complexity of IgE, IgG₄, and IgG epitope recognition at a global, allergome-wide level during allergen-specific immunotherapy (AIT).

METHODS

We generated an allergome-wide microarray comprising 731 allergens in the form of more than 172,000 overlapping 16-mer peptides. Allergen recognition by IgE, IgG₄, and IgG was examined in serum samples collected from subjects undergoing AIT against pollen allergy.

RESULTS

Extensive induction of linear peptide-specific Phl p 1- and Bet v 1-specific humoral immunity was demonstrated in subjects undergoing a 3-year-long AIT against grass and birch pollen allergy, respectively. Epitope profiles differed between subjects but were largely established already after 1 year of AIT, suggesting that dominant allergen-specific antibody clones remained as important contributors to humoral immunity following their initial establishment during the early phase of AIT. Complex, subject-specific patterns of allergen isoform and group cross-reactivities in the repertoires were observed, patterns that may indicate different levels of protection against different allergen sources.

CONCLUSIONS

The study highlights the complexity and subject-specific nature of allergen epitopes recognized following AIT. We envisage that epitope deconvolution will be an important aspect of future efforts to describe and analyze the outcomes of AIT in a personalized manner.

Microfluidic methods for precision diagnostics in food allergy

Food allergy has reached epidemic proportions and has become a significant source of healthcare burden. Oral food challenge, the gold standard for food allergy assessment, often is not performed because it places the patient at risk of developing anaphylaxis. However, conventional alternative food allergy tests lack a sufficient predictive value. Therefore, there is a critical need for better diagnostic tests that are both accurate and safe. Microfluidic methods have the potential of helping one to address such needs and to personalize the diagnostics. This article first reviews conventional diagnostic approaches used in food allergy. Second, it reviews recent efforts to develop novel biomarkers and in vitro diagnostics. Third, it summarizes the microfluidic methods developed thus far for food allergy diagnosis. The article concludes with a discussion of future opportunities for using microfluidic methods for achieving precision diagnostics in food allergy, including multiplexing the detection of multiple biomarkers, sampling of tissue-resident cytokines and immune cells, and multi-organ-on-a-chip technology.

Future research trends in understanding the mechanisms underlying allergic diseases for improved patient care

The specialties of allergy and clinical immunology have entered the era of precision medicine with the stratification of diseases into distinct disease subsets, specific diagnoses, and targeted treatment options, including biologicals and small molecules. This article reviews recent developments in research and patient care and future trends in the discipline. The section on basic mechanisms of allergic diseases summarizes the current status and defines research needs in structural biology, type 2 inflammation, immune tolerance, neuroimmune mechanisms, role of the microbiome and diet, environmental factors, and respiratory viral infections. In the section on diagnostic challenges, clinical trials, precision medicine and immune monitoring of allergic diseases, asthma, allergic and nonallergic rhinitis, and new approaches to the diagnosis and treatment of drug hypersensitivity reactions are discussed in further detail. In the third section, unmet needs and future research areas for the treatment of allergic diseases are highlighted with topics on food allergy, biologics, small molecules, and novel therapeutic concepts in allergen‐specific immunotherapy for airway disease. Unknowns and future research needs are discussed at the end of each subsection.

IgE repertoire and immunological memory: compartmental regulation and antibody function

It is now generally recognized that bone marrow is the survival niche for antigen-specific plasma cells with long-term immunological memory. These cells release antibodies into the circulation, needed to prime effector cells in the secondary immune response. These antibodies participate in the surveillance for antigen and afford immune defence against pathogens and toxins previously encountered in the primary immune response. IgE antibodies function together with their effector cells, mast cells, to exert 'immediate hypersensitivity' in mucosal tissues at the front line of immune defence. The constant supply of IgE antibodies from bone marrow plasma cells allows the rapid 'recall response' by mast cells upon re-exposure to antigen even after periods of antigen absence. The speed and sensitivity of the IgE recall response and potency of the effector cell functions are advantageous in the early detection and elimination of pathogens and toxins at the sites of attack. Local antigen provocation also stimulates de novo synthesis of IgE or its precursors of other isotypes that undergo IgE switching in the mucosa. This process, however, introduces a delay before mast cells can be sensitized and resume activity; this is terminated shortly after the antigen is eliminated. Recent results from adaptive immune receptor repertoire sequencing of immunoglobulin genes suggest that the mucosal IgE+ plasmablasts, which have undergone affinity maturation in the course of their evolution in vivo, are a source of long-lived IgE+ plasma cells in the bone marrow that are already fully functional.

Relationship between T-cell receptor α gene polymorphisms and symptomatic differences in patients with narcolepsy type 1

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Background:

Recent genome-wide association studies have identified an important role of T-cell receptor α (TRA) gene in the development of narcolepsy type 1. However, the role of TRA haplotype polymorphisms in the symptomatic diversity of narcolepsy remains unclear. This study aimed to investigate whether TRA polymorphisms can influence the symptomatic diversity of narcolepsy.

Methods:

Totally, 903 patients with narcolepsy type 1 were included in the study. Patients were divided into different groups according to their symptoms. First, 13 genotyped single nucleotide polymorphisms in the TRA were assessed for their association with symptoms of narcolepsy. We used the Chi-square test to determine differences in genotype frequencies in patients with narcolepsy. Further, we identified the haplotypes and variations of the TRA and tested their association with the symptoms of narcolepsy using a logistic regression model.

Results:

According to the results of the logistic regression, TRA haplotypes TG and CT were significantly associated with auditory hallucination, with odds ratios of 1.235 (95% confidence interval [CI], 1.012–1.507) and 1.236 (95% CI, 1.012–1.511), respectively (P < 0.05).

Conclusions:

The patterns of haplotype in TRA (haplotypes TG and CT) are associated with hypnagogic auditory hallucination in patients with narcolepsy type 1. However, further studies are needed to confirm our results and explore the underlying mechanisms.

Food allergy and omics

Food allergy (FA) prevalence has been increasing over the last few decades and is now a global health concern. Current diagnostic methods for FA result in a high number of false-positive results, and the standard of care is either allergen avoidance or use of epinephrine on accidental exposure, although currently with no other approved treatments. The increasing prevalence of FA, lack of robust biomarkers, and inadequate treatments warrants further research into the mechanism underlying food allergies. Recent technological advances have made it possible to move beyond traditional biological techniques to more sophisticated high-throughput approaches. These technologies have created the burgeoning field of omics sciences, which permit a more systematic investigation of biological problems. Omics sciences, such as genomics, epigenomics, transcriptomics, proteomics, metabolomics, microbiomics, and exposomics, have enabled the construction of regulatory networks and biological pathway models. Parallel advances in bioinformatics and computational techniques have enabled the integration, analysis, and interpretation of these exponentially growing data sets and opens the possibility of personalized or precision medicine for FA.

Severe T2-high asthma in the biologics era: European experts' opinion

The European Respiratory Biologics Forum gathered participants from 21 countries in Madrid, Spain, to discuss the management and treatment of severe asthma in the era of biologics. The current insights on the pathophysiology of severe asthma were discussed, as well as the role of respiratory biologics in clinical practice and strategies for eliminating chronic use of oral corticosteroids. The participants also highlighted the key challenges in identifying patients with severe asthma based on phenotypes, biomarkers and treatable traits, and the existing problems in patient referral to specialist care. The monitoring of treatment was debated and the need for a change towards precision medicine and personalised care was emphasised throughout the meeting. This review provides a summary of the discussions and highlights important concerns identified by the participants regarding the current management of severe asthma.

Stress, mindfulness, and the allergic patient

INTRODUCTION

The global incidence and prevalence of allergic diseases are increasing as is the intensity and duration of excessive psychological stress due to multiple factors associated with living in today's world such as personal, social and political unrest, increased fear and anxiety, and/or depression often leading to hopelessness. Both allergy and chronic psychological stress are characterized by immune imbalances that have similar characteristics. Thus, it is reasonable to posit that the two are interactive and stress may induce as well as complicate at least some allergic diseases. Areas covered: Stress management/reduction has been proposed with various physical, pharmacological, and psychological interventions for both preventive and therapeutic reasons. A useful intervention involves mindfulness techniques, which allow the individual to put their life situation in context for better personal management. Expert commentary: Future studies must be developed that will further examine the role of excess psychological stress in specific allergic diseases and evaluate the effectiveness of various stress intervention protocols, particularly those involving mindfulness, to determine which individual would best respond clinically to which intervention. When this is accomplished, assessment and treatment of psychological stress will become a standard component of clinical care for allergy, asthma, and other immune-based diseases.

Highlights in immune response, microbiome and precision medicine in allergic disease and asthma

Several recent key findings in immunology of allergic diseases that have led to a need of reassessment of our current thinking are reviewed in this issue of the journal. Recently developed strong evidence on the role of hygiene hypothesis in protection from allergic disease and its immune mechanisms is reviewed by Ober et al. The authors pointed out immunologic mechanisms of lower prevalence of asthma and allergic sensitization observed among Amish children living on traditional farms with higher endotoxin levels as compared to Hutterite children living on industrialized farms. Barcik et al. reviewed that biologically active histamine in humans is produced by certain bacteria in the gut in addition to several cells, and has broad immunoregulatory functions. Turcanu et al. reviewed immune mechanisms of a revolutionary change to protect from food allergy. The immunologic window of opportunity in the infants can be used to enable oral tolerance in severe allergy predisposed children. Accordingly, van de Veen et al. reviewed general mechanisms of allergen tolerance highlighting recent findings. Extensive usage of precision medicine due to emerging biologics is knocking the doors of allergic diseases and asthma. Boyd et al. reviewed the existing and future "immune monitoring" approaches in the multiple omics perspective with the hope of identifying better correlates of disease status, predictors of therapeutic outcomes, and potential side-effects of treatment. Paul et al. reviewed newly uncovered innate and adaptive immunologic mechanisms that contribute to the pathogenesis of eosinophilic esophagitis. Further highlighting newly developing disease subgroups and precision medicine, Guttman-Yassky & Kruger reviewed clinical subtypes of atopic dermatitis and psoriasis, which may potentially benefit from newly developing highly efficient biologicals. Complementing this paper, Kabashima & Nomura reviewed similarities and distinctions in mouse models of atopic dermatitis and psoriasis.