[The revolution of AI in drug development]

Artificial intelligence and machine learning enable the construction of predictive models, which are currently used to assist in decision-making throughout the process of drug discovery and development. These computational models can be used to represent the heterogeneity of a disease, identify therapeutic targets, design and optimize drug candidates, and evaluate the efficacy of these drugs on virtual patients or digital twins. By combining detailed patient characteristics with the prediction of potential drug-candidate properties, artificial intelligence promotes the emergence of a "computational" precision medicine, allowing for more personalized treatments, better tailored to patient specificities with the aid of such predictive models. Based on such new capabilities, a mixed reality approach to the development of new drugs is being adopted by the pharmaceutical industry, which integrates the outputs of predictive virtual models with real-world empirical studies.

High-content multimodal analysis supports the IL-7/IL-7 receptor axis as a relevant therapeutic target in primary Sjögren's syndrome

OBJECTIVE

While the involvement of IL-7/IL-7R axis in pSS has been described in relation to T cells, little is known about the contribution of this pathway in relationship with other immune cells, and its implication in autoimmunity. Using high-content multiomics data, we aimed at characterizing IL-7R expressing cells and the involvement of IL-7/IL-7R pathway in pSS pathophysiology.

METHODS

An IL-7 signature established using RNA-sequencing of human PBMCs incubated with IL-7 was applied to 304 pSS patients, and on RNA-Seq datasets from tissue biopsies. High-content immunophenotyping using flow and imaging mass cytometry was developed to characterize peripheral and in situ IL-7R expression.

RESULTS

We identified a blood 4-gene IL-7 module (IKZF4, KIAA0040, PGAP1 and SOS1) associated with anti-SSA/Ro positiveness in patients as well as disease activity, and a tissue 5-gene IL-7 module (IL7R, PCED1B, TNFSF8, ADAM19, MYBL1) associated with infiltration severity. We confirmed expression of IL-7R on T cells subsets, and further observed upregulation of IL-7R on double-negative (DN) B cells, and especially DN2 B cells. IL-7R expression was increased in pSS compared to sicca patients with variations seen according to the degree of infiltration. When expressed, IL-7R was mainly found on epithelial cells, CD4+ and CD8+ T cells, switched memory B cells, DN B cells and M1 macrophages.

CONCLUSION

This exhaustive characterization of the IL-7/IL-7R pathway in pSS pathophysiology established that two IL-7 gene modules discriminate pSS patients with a high IL-7 axis involvement. Their use could guide the implementation of an anti-IL-7R targeted therapy in a precision medicine approach.

Transforming drug discovery with a high-throughput AI-powered platform: A 5-year experience with Patrimony

High-throughput computational platforms are being established to accelerate drug discovery. Servier launched the Patrimony platform to harness computational sciences and artificial intelligence (AI) to integrate massive multimodal data from internal and external sources. Patrimony has enabled researchers to prioritize therapeutic targets based on a deep understanding of the pathophysiology of immuno-inflammatory diseases. Herein, we share our experience regarding main challenges and critical success factors faced when industrializing the platform and broadening its applications to neurological diseases. We emphasize the importance of integrating such platforms in an end-to-end drug discovery process and engaging human experts early on to ensure a transforming impact.

Artificial intelligence-driven drug development against autoimmune diseases

Artificial intelligence (AI)-based predictive models are being used to foster a precision medicine approach to treat complex chronic diseases such as autoimmune and autoinflammatory disorders (AIIDs). In the past few years the first models of systemic lupus erythematosus (SLE), primary Sjögren syndrome (pSS), and rheumatoid arthritis (RA) have been produced by molecular profiling of patients using omic technologies and integrating the data with AI. These advances have confirmed a complex pathophysiology involving multiple proinflammatory pathways and also provide evidence for shared molecular dysregulation across different AIIDs. I discuss how models are used to stratify patients, assess causality in pathophysiology, design drug candidates in silico, and predict drug efficacy in virtual patients. By relating individual patient characteristics to the predicted properties of millions of drug candidates, these models can improve the management of AIIDs through more personalized treatments.

Virtual patients, digital twins and causal disease models: paving the ground for in silico clinical trials

Computational models are being explored to simulate in silico the efficacy and safety of drug candidates and medical devices. Disease models that are based on patients' profiling data are being produced to represent interactomes of genes or proteins and to infer causality in the pathophysiology {AuQ: Edit OK?}, which makes it possible to mimic the impact of drugs on relevant targets. Virtual patients designed from medical records as well as digital twins were generated to simulate specific organs and to predict treatment efficacy at the individual patient level {AuQ: Edit OK?}. As the acceptance of digital evidence by regulators grows, predictive artificial intelligence (AI)-based models will support the design of confirmatory trials in humans and will accelerate the development of efficient drugs and medical devices.

Biomarker-driven development of new therapies for autoimmune diseases: current status and future promises

INTRODUCTION

Auto-immune diseases are complex and heterogeneous. Various types of biomarkers can be used to support precision medicine approaches to autoimmune diseases, ensuring that the right patient receives the most appropriate therapy to improve treatment outcomes.

AREAS COVERED

We review the recent progress made in modeling several autoimmune diseases such as Systemic Lupus Erythematosus, primary Sjogren Syndrome, and Rheumatoid Arthritis following extensive molecular profiling of large cohorts of patients. From this knowledge, BMKs are being identified which support diagnostic as well as patient stratification and prediction of response to treatment. The identification of biomarkers should be initiated early in drug development and properly validated during subsequent clinical trials. To ensure the robustness and reproducibility of biomarkers, the PERMIT Consortium recently established recommendations highlighting the importance of relevant study design, sample size, and appropriate validation of analytical methods.

EXPERT OPINION

The integration by AI-powered analytics of massive data provided by multi-omics technologies, high-resolution medical imaging and sensors borne by patients will eventually allow the identification of clinically relevant BMKs, likely in the form of combinatorial predictive algorithms, to support future drug development for autoimmune diseases.

Industrializing AI-powered drug discovery: lessons learned from the Patrimony computing platform

INTRODUCTION

As a mid-size international pharmaceutical company, we initiated four years ago the launch of a dedicated high-throughput computing platform supporting drug discovery. The platform named "Patrimony" was built-up on the initial predicate to capitalize on our proprietary data while leveraging public data sources in order to foster a Computational Precision Medicine approach with the power of Artificial Intelligence.

AREAS COVERED

Specifically, Patrimony is designed to identify novel therapeutic target candidates. With several successful use cases in Immuno-inflammatory diseases, and current ongoing extension to applications to Oncology and Neurology, we document how this industrial computational platform has had a transformational impact on our R&D, making it more competitive, as well time and cost effective through a model-based educated selection of therapeutic targets and drug candidates.

EXPERT OPINION

We report our achievements, but also our challenges in implementing data access and governance processes, building-up hardware and user interfaces, and acculturing scientists to use predictive models to inform decisions.

Proteomics in support of immunotherapy: contribution to model-based precision medicine

INTRODUCTION

Proteomics encompasses a wide and expanding range of methods to identify, characterize, and quantify thousands of proteins from a variety of biological samples, including blood samples, tumors, and tissues. Such methods are supportive of various forms of immunotherapy applied to chronic conditions such as allergies, autoimmune diseases, cancers, and infectious diseases.

AREAS COVERED

In support of immunotherapy, proteomics based on mass spectrometry has multiple specific applications related to (i) disease modeling and patient stratification, (ii) antigen/ autoantigen/neoantigen/ allergen identification, (iii) characterization of proteins and monoclonal antibodies used for immunotherapeutic or diagnostic purposes, (iv) identification of biomarkers and companion diagnostics and (v) monitoring by immunoproteomics of immune responses elicited in the course of the disease or following immunotherapy.

EXPERT OPINION

Proteomics contributes as an enabling technology to an evolution of immunotherapy toward a precision medicine approach aiming to better tailor treatments to patients' specificities in multiple disease areas. This trend is favored by a better understanding through multi-omics profiling of both the patient's characteristics, his/her immune status as well as of the features of the immunotherapeutic drug.

Model-based computational precision medicine to develop combination therapies for autoimmune diseases

INTRODUCTION

The complex pathophysiology of autoimmune diseases (AIDs) is being progressively deciphered, providing evidence for a multiplicity of pro-inflammatory pathways underlying heterogeneous clinical phenotypes and disease evolution.

AREAS COVERED

Treatment strategies involving drug combinations are emerging as a preferred option to achieve remission in a vast majority of patients affected by systemic AIDs. The design of appropriate drug combinations can benefit from AID modeling following a comprehensive multi-omics molecular profiling of patients combined with Artificial Intelligence (AI)-powered computational analyses. Such disease models support patient stratification in homogeneous subgroups, shed light on dysregulated pro-inflammatory pathways and yield hypotheses regarding potential therapeutic targets and candidate biomarkers to stratify and monitor patients during treatment. AID models inform the rational design of combination therapies interfering with independent pro-inflammatory pathways related to either one of five prominent immune compartments contributing to the pathophysiology of AIDs, i.e. pro-inflammatory signals originating from tissues, innate immune mechanisms, T lymphocyte activation, autoantibodies and B cell activation, as well as soluble mediators involved in immune cross-talk.

EXPERT OPINION

The optimal management of AIDs in the future will rely upon rationally designed combination therapies, as a modality of a model-based Computational Precision Medicine taking into account the patients' biological and clinical specificities.

A deep learning method for predicting knee osteoarthritis radiographic progression from MRI

Background

The identification of patients with knee osteoarthritis (OA) likely to progress rapidly in terms of structure is critical to facilitate the development of disease-modifying drugs.

Methods

Using 9280 knee magnetic resonance (MR) images (3268 patients) from the Osteoarthritis Initiative (OAI) database , we implemented a deep learning method to predict, from MR images and clinical variables including body mass index (BMI), further cartilage degradation measured by joint space narrowing at 12 months.

Results

Using COR IW TSE images, our classification model achieved a ROC AUC score of 65%. On a similar task, trained radiologists obtained a ROC AUC score of 58.7% highlighting the difficulty of the classification task. Additional analyses conducted in parallel to predict pain grade evaluated by the WOMAC pain index achieved a ROC AUC score of 72%. Attention maps provided evidence for distinct specific areas as being relevant in those two predictive models, including the medial joint space for JSN progression and the intra-articular space for pain prediction.

Conclusions

This feasibility study demonstrates the interest of deep learning applied to OA, with a potential to support even trained radiologists in the challenging task of identifying patients with a high-risk of disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02634-4.

Artificial intelligence-enhanced drug design and development: Toward a computational precision medicine

Artificial Intelligence (AI) relies upon a convergence of technologies with further synergies with life science technologies to capture the value of massive multi-modal data in the form of predictive models supporting decision-making. AI and machine learning (ML) enhance drug design and development by improving our understanding of disease heterogeneity, identifying dysregulated molecular pathways and therapeutic targets, designing and optimizing drug candidates, as well as evaluating in silico clinical efficacy. By providing an unprecedented level of knowledge on both patient specificities and drug candidate properties, AI is fostering the emergence of a computational precision medicine allowing the design of therapies or preventive measures tailored to the singularities of individual patients in terms of their physiology, disease features, and exposure to environmental risks.

Network-based repurposing identifies anti-alarmins as drug candidates to control severe lung inflammation in COVID-19

While establishing worldwide collective immunity with anti SARS-CoV-2 vaccines, COVID-19 remains a major health issue with dramatic ensuing economic consequences. In the transition, repurposing existing drugs remains the fastest cost-effective approach to alleviate the burden on health services, most particularly by reducing the incidence of the acute respiratory distress syndrome associated with severe COVID-19. We undertook a computational repurposing approach to identify candidate therapeutic drugs to control progression towards severe airways inflammation during COVID-19. Molecular profiling data were obtained from public sources regarding SARS-CoV-2 infected epithelial or endothelial cells, immune dysregulations associated with severe COVID-19 and lung inflammation induced by other respiratory viruses. From these data, we generated a protein-protein interactome modeling the evolution of lung inflammation during COVID-19 from inception to an established cytokine release syndrome. This predictive model assembling severe COVID-19-related proteins supports a role for known contributors to the cytokine storm such as IL1β, IL6, TNFα, JAK2, but also less prominent actors such as IL17, IL23 and C5a. Importantly our analysis points out to alarmins such as TSLP, IL33, members of the S100 family and their receptors (ST2, RAGE) as targets of major therapeutic interest. By evaluating the network-based distances between severe COVID-19-related proteins and known drug targets, network computing identified drugs which could be repurposed to prevent or slow down progression towards severe airways inflammation. This analysis confirmed the interest of dexamethasone, JAK2 inhibitors, estrogens and further identified various drugs either available or in development interacting with the aforementioned targets. We most particularly recommend considering various inhibitors of alarmins or their receptors, currently receiving little attention in this indication, as candidate treatments for severe COVID-19.

IFN-α: A key therapeutic target for multiple autoimmune rheumatic diseases

Interferon (IFN)-α has emerged as a major therapeutic target for several autoimmune rheumatic diseases. In this review, we focus on clinical and preclinical advances in anti-IFN-α treatments in systemic lupus erythematosus (SLE), primary Sjögren syndrome (pSS), systemic sclerosis (SSc), and dermatomyositis (DM), for which a high medical need persists. Promising achievements were obtained following direct IFN-α neutralization, targeting its production through the cytosolic nucleic acid sensor pathways or by blocking its downstream effects through the type I IFN receptor. We further focus on molecular profiling and data integration approaches as crucial steps to select patients most likely to benefit from anti-IFN-α therapies within a precision medicine approach.

A new molecular classification to drive precision treatment strategies in primary Sjögren's syndrome

There is currently no approved treatment for primary Sjögren's syndrome, a disease that primarily affects adult women. The difficulty in developing effective therapies is -in part- because of the heterogeneity in the clinical manifestation and pathophysiology of the disease. Finding common molecular signatures among patient subgroups could improve our understanding of disease etiology, and facilitate the development of targeted therapeutics. Here, we report, in a cross-sectional cohort, a molecular classification scheme for Sjögren's syndrome patients based on the multi-omic profiling of whole blood samples from a European cohort of over 300 patients, and a similar number of age and gender-matched healthy volunteers. Using transcriptomic, genomic, epigenetic, cytokine expression and flow cytometry data, combined with clinical parameters, we identify four groups of patients with distinct patterns of immune dysregulation. The biomarkers we identify can be used by machine learning classifiers to sort future patients into subgroups, allowing the re-evaluation of response to treatments in clinical trials.

S95021, a novel selective and pan-neutralizing anti interferon alpha (IFN-α) monoclonal antibody as a candidate treatment for selected autoimmune rheumatic diseases

Increased interferon-α (IFN-α) production is a critical component in the pathophysiology of systemic lupus erythematosus (SLE) and other rheumatic autoimmune diseases. Herein, we report the characterization of S95021, a fully human IgG1 anti-IFN-α monoclonal antibody (mAb) as a novel therapeutic candidate for targeted patient populations. S95021 was expressed in CHOZN GS-/- cells, purified by chromatography and characterized by using electrophoresis, size exclusion chromatography and liquid chromatography-mass spectrometry. High purity S95021 was obtained as a monomeric entity comprising different charge variants mainly due to N-glycosylation. Surface plasmon resonance kinetics experiments showed strong association rates with all IFN-α subtypes and estimated KDs below picomolar values. Pan-IFN-α-binding properties were confirmed by immunoprecipitation assays and neutralization capacity with reporter HEK-Blue IFN-α/β cells. S95021 was IFN-α-selective and exhibited superior potency and broader neutralization profile when compared with the benchmark anti-IFN-α mAbs rontalizumab and sifalimumab. STAT-1 phosphorylation and the type I IFN gene signature induced in human peripheral blood mononuclear cells by recombinant IFN-α subtypes or plasmas from selected autoimmune patients were efficiently reduced by S95021 in a dose-dependent manner. Together, our results show that S95021 is a new potent, selective and pan IFN-α-neutralizing mAb. It is currently further evaluated as a valid therapeutic candidate in selected autoimmune diseases in which the IFN-α pro-inflammatory pathway is dysregulated.

[Applications of artificial intelligence to new drug development]

Artificial intelligence (AI) encompasses technologies recapitulating four dimensions of human intelligence, i.e. sensing, thinking, acting and learning. The convergence of technological advances in those fields allows to integrate massive data and build probabilistic models of a problem. The latter can be continuously updated by incorporating new data to inform decision-making and predict the future. In support of drug discovery and development, AI allows to generate disease models using data obtained following extensive molecular profiling of patients. Given its superior computational power, AI can integrate those big multimodal data to generate models allowing: (i) to represent patient heterogeneity; and (ii) identify therapeutic targets with inferences of causality in the pathophysiology. Additional computational analyses can help identifying and optimizing drugs interacting with these targets, or even repurposing existing molecules for a new indication. AI-based modeling further supports the identification of biomarkers of efficacy, the selection of appropriate combination therapies and the design of innovative clinical studies with virtual placebo groups. The convergence of biotechnologies, drug sciences and AI is fostering the emergence of a computational precision medicine predicted to yield therapies or preventive measures precisely tailored to patient characteristics in terms of their physiology, disease features and environmental risk exposure.

Author Correction: A dynamic COVID-19 immune signature includes associations with poor prognosis

A Correction to this paper has been published: https://doi.org/10.1038/s41591-020-01186-5.

A dynamic COVID-19 immune signature includes associations with poor prognosis

Improved understanding and management of COVID-19, a potentially life-threatening disease, could greatly reduce the threat posed by its etiologic agent, SARS-CoV-2. Toward this end, we have identified a core peripheral blood immune signature across 63 hospital-treated patients with COVID-19 who were otherwise highly heterogeneous. The signature includes discrete changes in B and myelomonocytic cell composition, profoundly altered T cell phenotypes, selective cytokine/chemokine upregulation and SARS-CoV-2-specific antibodies. Some signature traits identify links with other settings of immunoprotection and immunopathology; others, including basophil and plasmacytoid dendritic cell depletion, correlate strongly with disease severity; while a third set of traits, including a triad of IP-10, interleukin-10 and interleukin-6, anticipate subsequent clinical progression. Hence, contingent upon independent validation in other COVID-19 cohorts, individual traits within this signature may collectively and individually guide treatment options; offer insights into COVID-19 pathogenesis; and aid early, risk-based patient stratification that is particularly beneficial in phasic diseases such as COVID-19.

Author Correction: A dynamic COVID-19 immune signature includes associations with poor prognosis

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

State-of-the-art in marketed adjuvants and formulations in Allergen Immunotherapy: A position paper of the European Academy of Allergy and Clinical Immunology (EAACI)

Since the introduction of allergen immunotherapy (AIT) over 100 years ago, focus has been on standardization of allergen extracts, with reliable molecular composition of allergens receiving the highest attention. While adjuvants play a major role in European AIT, they have been less well studied. In this Position Paper, we summarize current unmet needs of adjuvants in AIT citing current evidence. Four adjuvants are used in products marketed in Europe: aluminium hydroxide (Al(OH)₃ ) is the most frequently used adjuvant, with microcrystalline tyrosine (MCT), monophosphoryl lipid A (MPLA) and calcium phosphate (CaP) used less frequently. Recent studies on humans, and using mouse models, have characterized in part the mechanisms of action of adjuvants on pre-existing immune responses. AIT differs from prophylactic vaccines that provoke immunity to infectious agents, as in allergy the patient is presensitized to the antigen. The intended mode of action of adjuvants is to simultaneously enhance the immunogenicity of the allergen, while precipitating the allergen at the injection site to reduce the risk of anaphylaxis. Contrasting immune effects are seen with different adjuvants. Aluminium hydroxide initially boosts Th2 responses, while the other adjuvants utilized in AIT redirect the Th2 immune response towards Th1 immunity. After varying lengths of time, each of the adjuvants supports tolerance. Further studies of the mechanisms of action of adjuvants may advise shorter treatment periods than the current three-to-five-year regimens, enhancing patient adherence. Improved lead compounds from the adjuvant pipeline are under development and are explored for their capacity to fill this unmet need.

CCR10+ ILC2s with ILC1-like properties exhibit a protective function in severe allergic asthma

BACKGROUND

We previously showed that patients with severe allergic asthma have high numbers of circulating ILC2s expressing CCR10.

METHOD

Herein, CCR10⁺ ILC2s were further analyzed in the blood of healthy individuals or patients with allergic and non-allergic asthma. Characteristics of human CCR10⁺ and CCR10^- ILC2s were assessed by flow cytometry as well as single-cell multiplex RT-qPCR. The role of CCR10⁺ ILC2s in asthma pathophysiology was studied in allergen-treated mice.

RESULTS

When compared to healthy controls, CCR10⁺ ILC2s are enriched in the blood of both allergic and non-allergic severe asthmatic patients, and these cells are recruited to the lungs. Plasma concentrations of the CCR10 ligand CCL27 are significantly increased in severe asthmatics when compared to non-asthmatic patients. CCR10⁺ ILC2s secrete little T_H 2 cytokines, but exhibit ILC1-like properties, including a capacity to produce IFN-γ. Also, single-cell analysis reveals that the CCR10⁺ ILC2 subset is enriched in cells expressing amphiregulin. CCR10⁺ ILC2 depletion, as well as blocking of IFN-γ activity, exacerbates airway hyperreactivity in allergen-challenged mice, providing evidence for a protective role of these cells in allergic inflammation.

CONCLUSIONS

Frequencies of circulating CCR10⁺ ILC2s and CCL27 plasma concentrations represent candidate markers of asthma severity. The characterization of CCR10⁺ ILC2s in human samples and in mouse asthma models suggests that these cells downregulate allergic inflammation through IFN-γ production.

Characterization of epitope specificities of reference antibodies used for the quantification of the birch pollen allergen Bet v 1

BACKGROUND

Accurate allergen quantification is needed to document the consistency of allergen extracts used for immunotherapy. Herein, we characterize the epitope specificities of two monoclonal antibodies used in an ELISA for the quantification of the major birch pollen allergen Bet v 1, established as a reference by the BSP090 European project.

METHODS

The ability of mAbs 5B4 and 6H4 to recognize Bet v 1 isoforms was addressed by immunochromatography. The capacity of each mAb to compete with patients' IgE for binding to Bet v 1 was measured by ELISA inhibition. Epitope mapping was performed by pepscan analysis, site-directed mutagenesis, and hydrogen/deuterium exchange-mass spectrometry.

RESULTS

The 5B4 epitope corresponds to a peptide sequence (I56-K68) overlapping with the binding sites of patients' serum IgEs. Mutation of residues P59, E60, and K65 abolishes 5B4 binding to Bet v 1 and reduces the level of IgE recognition. In contrast, 6H4 recognizes a conformational epitope lying opposite to the 5B4 binding site, involving residues located in segments I44-K55 and R70-F79. Substitution of E45 reduces the binding capacity of 6H4, confirming that it is critical for the interaction. Both mAbs interact with >90% of Bet v 1 content present in the birch pollen extract, while displaying a weak cross-reactivity with other allergens of the PR-10 family.

CONCLUSIONS

MAbs 5B4 and 6H4 recognize structurally distinct epitopes present in the vast majority of Bet v 1 isoforms. These results support the relevance as a reference method of the Bet v 1-specific quantitative ELISA adopted by the European Pharmacopoeia.

Enhancing Allergen-Presentation Platforms for Sublingual Immunotherapy

Sublingual immunotherapy (SLIT) relies on high doses of allergens to treat patients with type I allergies. Although SLIT is commonly performed without any adjuvant or delivery system, allergen(s) could be further formulated with allergen-presentation platforms to better target oral dendritic cells eliciting regulatory immune responses. Improving the availability of allergens to the immune system should enhance SLIT efficacy, while allowing to decrease allergen dosing. Herein, we present an overview of adjuvants and vector systems that have been, or could be, considered as candidate allergen-presentation platforms for the sublingual route. Such platforms encompass adjuvants capable of stimulating allergen-specific T_H1 and/or regulatory CD4⁺ T-cell responses, including 1,25-dihydroxy vitamin D₃, glucocorticoids, Toll-like receptor ligands as well as selected bacterial probiotic strains. A limiting factor for SLIT efficacy is the number of dendritic cells capturing the allergens in the upper layers of oral tissues. Thus, adsorption or encapsulation of the allergen(s) within mucoadhesive particulate vector (or delivery) systems also has the potential to significantly enhance SLIT efficacy due to a facilitated allergen uptake by tolerogenic oral dendritic cells.

A combined transcriptome and proteome analysis extends the allergome of house dust mite Dermatophagoides species

Background

House dust mites (HDMs) such as Dermatophagoides farinae and D. pteronyssinus represent major causes of perennial allergy. HDM proteomes are currently poorly characterized, with information mostly restricted to allergens. As of today, 33 distinct allergen groups have been identified for these 2 mite species, with groups 1 and 2 established as major allergens. Given the multiplicity of IgE-reactive mite proteins, potential additional allergens have likely been overlooked.

Objective

To perform a comprehensive characterization of the transcriptomes, proteomes and allergomes of D. farinae and D. pteronyssinus in order to identify novel allergens.

Methods

Transcriptomes were analyzed by RNA sequencing and de novo assembly. Comprehensive mass spectrometry-based analyses proteomes were combined with two-dimensional IgE reactivity profiling.

Results

Transcripts from D. farinae and D. pteronyssinus were assembled, translated into protein sequences and used to populate derived sequence databases in order to inform immunoproteomic analyses. A total of 527 and 157 proteins were identified by bottom-up MS analyses in aqueous extracts from purified HDM bodies and fecal pellets, respectively. Based on high sequence similarities (>71% identity), we also identified 2 partial and 11 complete putative sequences of currently undisclosed D. pteronyssinus counterparts of D. farinae registered allergens. Immunoprofiling on 2D-gels revealed the presence of unknown 23 kDa IgE reactive proteins in both species. Following expression of non-glycosylated recombinant forms of these molecules, we confirm that these new allergens react with serum IgEs from 42% (8/19) of HDM-allergic individuals.

Conclusions

Using combined transcriptome and immunoproteome approaches, we provide a comprehensive characterization of D. farinae and D. pteronyssinus allergomes. We expanded the known allergen repertoire for D. pteronyssinus and identified two novel HDM allergens, now officially referred by the International Union of Immunological Societies (IUIS) Nomenclature Subcommittee as Der f 36 and Der p 36.

Differences and similarities between sublingual immunotherapy of allergy and oral tolerance

Allergen immunotherapy is the only treatment altering the natural course of IgE-mediated allergies. Whereas the subcutaneous route for immunotherapy (SCIT) has been historically considered as a reference, we discuss herein the relative advantages of the sublingual and oral routes as alternatives to SCIT in order to elicit allergen-specific tolerance. The buccal and gut immune systems are similarly organized to favor immune tolerance to antigens/allergens, due to the presence of tolerogenic dendritic cells and macrophages promoting the differentiation of CD4⁺ regulatory T cells. Sublingual immunotherapy (SLIT) is now established as a valid treatment option, with clinical efficacy demonstrated in allergic rhinoconjunctivitis (to either grass, tree, weed pollens or mite allergens) and encouraging results obtained in the management of mild/moderate allergic asthma. While still exploratory, oral immunotherapy (OIT) has shown promising results in the desensitization of patients with food allergies. We review at both biological and clinical levels the perspectives currently pursued for those two mucosal routes.

Novel approaches and perspectives in allergen immunotherapy

In this review, we report on relevant current topics in allergen immunotherapy (AIT) which were broadly discussed during the first Aarhus Immunotherapy Symposium (Aarhus, Denmark) in December 2015 by leading clinicians, scientists and industry representatives in the field. The aim of this symposium was to highlight AIT-related aspects of public health, clinical efficacy evaluation, mechanisms, development of new biomarkers and an overview of novel therapeutic approaches. Allergy is a public health issue of high socioeconomic relevance, and development of evidence-based action plans to address allergy as a public health issue ought to be on national and regional agendas. The underlying mechanisms are in the focus of current research that lays the ground for innovative therapies. Standardization and harmonization of clinical endpoints in AIT trials as well as current knowledge about potential biomarkers have substantiated proof of effectiveness of this disease-modifying therapeutic option. Novel treatments such as peptide immunotherapy, intralymphatic immunotherapy and use of recombinant allergens herald a new age in which AIT may address treatment of allergy as a public health issue by reaching a large fraction of patients.

Effector and regulatory dendritic cells display distinct patterns of miRNA expression

Introduction

MicroRNAs (miRNAs) contribute to the regulation of dendritic cell (DC) polarization, thereby influencing the balance of adaptive immune responses. Herein, we studied the expression of miRNAs in polarized DCs and analyzed whether expression of these miRNAs could be associated with allergic rhinitis and allergen immunotherapy (AIT) outcome.

Method

Using specific culture conditions, we differentiated immature human monocyte‐derived DCs into DC1, DC2, and DCreg subsets (supporting the differentiation of T_H1, T_H2 or regulatory T cells, respectively). Profiling of miRNA expression was performed in these DC subpopulations using microarrays. Levels of miRNAs specific for polarized DCs were then evaluated in a cohort of 58 patients with allergic rhinitis and 25 non‐allergic controls, as well as in samples from 30 subjects treated with sublingual grass pollen tablets or placebo for four months.

Results

We successfully identified 16 miRNAs differentially regulated between immature DCs, DC1, DC2, and DCreg cells. In allergic rhinoconjunctivitis patients, the expression of two of those miRNAs (miR‐132 and miR‐155), was down‐regulated compared to non‐allergic individuals. However, the levels of these miRNAs were not significantly modified following four months of grass pollen immunotherapy.

Conclusions

Studying polarized DCs and clinical samples from subjects with or without allergic rhinoconjunctivitis, we demonstrated that the expression of two miRNAs linked to effector DCs (i.e., DC1 and/or DC2 cells), was reduced in the blood of patients with allergic rhinoconjunctivitis. Nevertheless, these miRNAs did not represent relevant biomarkers to predict or follow‐up AIT efficacy.

The regulatory dendritic cell marker C1q is a potent inhibitor of allergic inflammation

The complement subunit C1q was recently identified as a marker for monocyte-derived regulatory dendritic cells supporting the differentiation of interleukin (IL)-10-secreting CD4⁺ T cells with a suppressive activity. Furthermore, C1q expression is upregulated in peripheral blood mononuclear cells of allergic patients in the course of successful allergen immunotherapy. Herein, we investigated a potential direct role of C1q in downregulating allergic inflammation. In mice with ovalbumin (OVA) or birch pollen (BP)-induced allergic asthma, C1q is as efficacious as dexamethasone to reduce both airway hyperresponsiveness (AHR), eosinophil, and ILC2 infiltrates in bronchoalveolar lavages, as well as allergen-specific T helper 2 cells in the lungs. Administration of C1q does not expand IL-10⁺/Foxp3⁺ regulatory T cells in the lungs, spleen, or in the blood. Depletion of plasmacytoid dendritic cells (pDCs) abrogates the capacity of C1q to reduce AHR and eosinophilic infiltrates in OVA-sensitized mice. Also C1q treatment inhibits the activation of human and mouse pDCs by CpGs, thereby demonstrating a critical role for pDCs in the anti-inflammatory activity of C1q. We conclude that regulatory dendritic cells can mediate a potent direct anti-inflammatory activity via the expression and/or secretion of molecules such as C1q, independently of their capacity to expand the pool of regulatory T cells.

Validation of ELISA methods for quantification of the major birch allergen Bet v 1 (BSP090)

To date, the potency of allergen products in Europe is expressed in manufacturer-specific units relative to a product-specific in-house reference. Consequently, cross-product comparability of allergen products from different manufacturers with respect to strength and efficacy is impossible. The Biological Standardisation Programme (BSP) project BSP090 addresses this issue via the establishment of reference standards in conjunction with ELISA methods for the quantification of major allergens in allergen products. Since the initiation of BSP090, the recombinant major allergen Bet v 1 has been adopted by the European Pharmacopoeia Commission as a Chemical Reference Substance (CRS). In parallel, two sandwich ELISA systems for quantification of Bet v 1 were found suitable in preliminary phases of BSP090 to be validated in a large collaborative study. In this study, the candidate ELISA systems were compared with respect to accuracy, precision and variability. Thirteen participating laboratories tested model samples containing the CRS as well as spiked and unspiked birch pollen extracts. Both in pre-testing and in the collaborative study, the 2 candidate ELISA systems confirmed their suitability to quantify recombinant and native Bet v 1. As no clear-cut decision for one of the ELISA systems could be made based on the results of the collaborative study, a post-study testing was performed. Bet v 1 content of 30 birch pollen allergen products was determined in parallel in both ELISA systems. Consequently, 1 candidate ELISA system was selected to be proposed as the future European Pharmacopoeia standard method for Bet v 1 quantification.

Sialylated Fetuin-A as a candidate predictive biomarker for successful grass pollen allergen immunotherapy

BACKGROUND

Eligibility to immunotherapy is based on the determination of IgE reactivity to a specific allergen by means of skin prick or in vitro testing. Biomarkers predicting the likelihood of clinical improvement during immunotherapy would significantly improve patient selection.

METHODS

Proteins were differentially assessed by using 2-dimensional differential gel electrophoresis and label-free mass spectrometry in pretreatment sera obtained from clinical responders and nonresponders within a cohort of 82 patients with grass pollen allergy receiving sublingual immunotherapy or placebo. Functional studies of Fetuin-A (FetA) were conducted by using gene silencing in a mouse asthma model, human dendritic cell in vitro stimulation assays, and surface plasmon resonance.

RESULTS

Analysis by using quantitative proteomics of pretreatment sera from patients with grass pollen allergy reveals that high levels of O-glycosylated sialylated FetA isoforms are found in patients exhibiting a strong decrease in rhinoconjunctivitis symptoms after sublingual immunotherapy. Although FetA is involved in numerous inflammatory conditions, its potential role in allergy is unknown. In vivo silencing of the FETUA gene in BALB/c mice results in a dramatic upregulation of airway hyperresponsiveness, lung resistance, and T_H2 responses after allergic sensitization to ovalbumin. Both sialylated and nonsialytated FetA bind to LPS, but only the former synergizes with LPS and grass pollen or mite allergens to enhance the Toll-like receptor 4-mediated proallergic properties of human dendritic cells.

CONCLUSIONS

As a reflection of the patient's inflammatory status, pretreatment levels of sialylated FetA in the blood are indicative of the likelihood of clinical responses during grass pollen immunotherapy.

6th International Symposium on Molecular Allergology (ISMA)

ORAL ABSTRACTS

Symposium 1: Biochemistry, structure and environment of the allergen: what makes a protein an allergen?

O1 Two cell-membrane peptidases carrying galactose-alpha-1,3-galactose are implicated in delayed anaphylactic reactions upon pork kidney ingestion in patients with IgE-antibodies to alpha-Gal

Christiane Hilger, Kyra Swiontek, Jörg Fischer, François Hentges, Christiane Lehners, Martine Morisset, Bernadette Eberlein, Tilo Biedermann, Markus Ollert

O2 Structure solution of Pla l 1 suggests similar folding of Ole e 1-like family members but distinct immunological properties

Sabrina Wildner, Teresa Stemeseder, Regina Freier, Peter Briza, Roland Lang, Eva Batanero, Mayte Villalba, Jonas Lidholm, Thomas Hawranek, Fatima Ferreira, Hans Brandstetter, Gabriele Gadermaier

Symposium 2: New allergen molecules in the spotlight

O3 Identification of the cysteine protease Amb a 11 as a novel major allergen from short ragweed (Ambrosia artemisiifolia)

Philippe Moingeon, Rachel Groeme, Julien Bouley, Véronique Bordas, Maxime Le Mignon, Laetitia Bussières, Aurélie Lautrette, Laurent Mascarell, Vincent Lombardi, Véronique Baron-Bodo, Henri Chabre, Thierry Batard, Emmanuel Nony

O4 Production and characterization of polybia paulista recombinant antigen 5: a valuable diagnostic tool

Karine Marafigo De Amicis, Alexandra Sayuri Watanabe, Daniele Danella Figo, José Roberto Aparecido Dos Santos-Pinto, Mario Sergio Palma, Fabio Fernandes Morato Castro, Jorge Kalil, Therese Wohlschlager, Peter Briza, Sabrina Wildner, Fatima Ferreira-Briza, Gabriele Gadermaier, Keity Souza Santos

Symposium 3: Progress in molecular and cellular diagnosis

O5 Basophil activation test with recombinant Pru p 3; identifying genuine peach allergic patients

Margaretha Faber, Athina Van Gasse, Vito Sabato, Margo M. Hagendorens, Chris H. Bridts, Luc S. De Clerck, Araceli Diaz Perales, Didier Ebo

O6 Nanofluidic technology enables rapid, near-patient quantification of allergen-specific IgE

Petra Zavadakova, Aurélie Buchwalder, Fabien Rebeaud, Iwan Märki

Symposium 4: Relevance of molecular diagnostics for intervention and treatment

O7 Longitudinal analysis of Bet v 1-specific epitope repertoires during birch pollen immunotherapy

Barbara Gepp, Nina Lengger, Christian Möbs, Wolfgang Pfützner, Christian Radauer, Barbara Bohle

O8 A natural CCD-free tool: is polistes sp. venom suitable for polybia paulista diagnosis and therapy?

Karine Marafigo De Amicis, Alexandra Sayuri Watanabe, Clovis Eduardo Galvao, Daniele Danella Figo, Jose Roberto Aparecido Santos-Pinto, Mario Sergio Palma, Fabio Fernandes Morato Castro, Jorge Kalil, Fatima Ferreira, Gabriele Gadermaier, Keity Souza Santos

Symposium 5: The advent of molecular allergology in epidemiology

O9 Peanut oleosins: from identification to diagnostic testing

Christian Schwager, Skadi Kull, Frauke Schocker, Jochen Behrends, Wolf-Meinhard Becker, Uta Jappe

O10 Endotypes of oral allergy syndrome in childhood: a molecular diagnostic approach

Carla Mastrorilli, Salvatore Tripodi, Carlo Caffarelli, Riccardo Asero, Arianna Dondi, Giampaolo Ricci, Carlotta Povesi Dascola, Elisabetta Calamelli, Andrea Di Rienzo Businco, Annamaria Bianchi, Tullio Frediani, Carmen Verga, Iride Dello Iacono, Diego Peroni, Giuseppe Pingitore, Roberto Bernardini, Paolo Maria Matricardi

Symposium 6: Molecular AIT: which approaches will make it to market?

O11 Mbc4: an innovative molecule to tackle birch pollen and concomitant food allergies

Heidi Hofer, Claudia Asam, Michael Hauser, Peter Briza, Martin Himly, Christof Ebner, Fatima Ferreira

O12 Challenges and solutions associated with the production of recombinant Bet v 1 allergen as a therapeutic protein

Emmanuel Nony, Maxime Le Mignon, Pierrick Lemoine, Karine Jain, Kathy Abiteboul, Monica Arvidsson, Sabina Rak, Philippe Moingeon

Clinical Cases: Breakthroughs and headaches from CRD: interactive session

CC1 Anaphylaxis caused by lipid transfer proteins: a complex clinical pattern syndrome

Inês Mota, Filipe Benito Garcia, Angela Gaspar, Cristina Arêde, Susana Piedade, Graça Sampaio, Graça Pires, Luís Miguel Borrego, Cristina Santa-Marta, Mário Morais-Almeida

CC2 IgE sensitization profile in a patient with asteraceae pollen-exotic fruits association

Florin-Dan Popescu, Mariana Vieru, Florin-Adrian Secureanu

CC3 Food-dependent: exercise induced anaphylaxis. Which component to blame?

Rosa Anita Rodrigues Fernandes, Isabel Carrapatoso, Raquel Gomes, Celso Pereira, Ana Todo-Bom

CC4 Anaphylaxis to intravenous iron preparations in a patient that tolerates oral administration

María Cecilia Martín Fernández De Basoa, Javier Barrios Regio, Juan De Castro Cordova, Antón Fernández Ferreiro

CC5 IgE sensitization pattern in an adult patient with oral allergy syndrome to peanuts and pollinosis from southern Romania

Florin-Dan Popescu, Mariana Vieru, Florin-Adrian Secureanu

CC6 Evidence of specific IgE to plant-derived cross-reactive carbohydrate determinant in a patient with delayed anaphylaxis to red meat

Mariana Vieru, Florin-Dan Popescu, Florin-Adrian Secureanu

POSTER PRESENTATIONS

Poster Session 1: Molecular allergology and epidemiology

P1 Atopic children produce stronger and more frequent IgG responses than non-atopic children: longitudinal data from the German MAS birth cohort

Olympia Tsilochristou, Serena Perna, Alina Schwarz, Alexander Rohrbach, Antonio Cappella, Laura Hatzler, Carl-Peter Bauer, Ute Hoffmann, Johannes Forster, Fred Zepp, Antje Schuster, Raffael D’amelio, Ulrich Wahn, Thomas Keil, Susanne Lau, Paolo Maria Matricardi

P2 The IgG sensitization profiles against 112 allergenic components support the absence of a protective role of IgG in allergic individuals, outside of the context of SIT

Pol André Apoil, Claire Mailhol, Anne Broué-Chabbert, Agnès Juchet, Alain Didier, Elodie Carrer, Thomas Lanot, Antoine Blancher

P3 The immune response against the timothy grass pollen allergen Phl p 5 in non-allergic humans

Almedina Kurtaj, Christoph Hillebrand, Gerda Fichtinger, Martin Danzer, Christian Gabriel, Theresa Thalhamer, Sandra Scheiblhofer, Josef Thalhamer, Richard Weiss

P4 Analyzing the cross-reactivity profile of the major ragweed allergen Amb a 1

Martin Wolf, Michael Hauser, Ulrike Pichler, Teresa Twaroch, Gabriele Gadermaier, Christof Ebner, Hidenori Yokoi, Toshiro Takai, Alain Didierlaurent, Adriano Mari, Peter Briza, Heidrun Behrendt, Angela Neubauer, Frank Stolz, Fátima Ferreira, Michael Wallner

P5 LTP (Pru p 3) sensitisation in skin prick test: which means in clinical practice?

Sara Carvalho, Tatiana Lourenço, Joana Cosme, Fátima Cabral Duarte, Amélia Spínola Santos, Ana Célia Costa, Manuel Pereira Barbosa

P6 IgE profiles, allergen exposure and lifestyle of 501 Austrian pupils: investigation of influences on the development of allergic sensitizations

Teresa Stemeseder, Eva Klinglmayr, Bettina Schweidler, Lisa Lueftenegger, Stephanie Moser, Patrick Doppler, Roland Lang, Martin Himly, Gertie J. Oostingh, Arne Bathke, Joerg Zumbach, Thomas Hawranek, Gabriele Gadermaier

P7 Molecular profiles of sensitization to perennial inhalant allergens in a middle European region

Petr Panzner, Martina Vachova, Tomas Vlas, Marek Maly

P8 Evolution of the IgE response to house dust mite allergen molecules in childhood

Daniela Posa, Serena Perna, Stephanie Hofmaier, Laura Hatzler, Alexander Rohrbach, Carl-Peter Bauer, Ute Hoffmann, Johannes Forster, Fred Zepp, Antje Schuster, Philippe Stock, Ulrich Wahn, Linus Grabenhenrich, Thomas Keil, Susanne Lau, Kuan-Wei Chen, Yvonne Resch, Susanne Vrtala, Rudolf Valenta, Paolo Maria Matricardi

P9 Tropomyosin (Pen a1): to include or not to include in skin prick testing?

Joana Cosme, Sara Carvalho, Tatiana Lourenço, Amélia Spínola Santos, Manuel Pereira Barbosa

Immunoallergy Department - Hospital de Santa Maria – Centro Hospitalar Lisboa Norte, Lisbon, Portugal, Lisbon, Portugal; Immunoallergy Department - Hospital de Santa Maria – Centro Hospitalar Lisboa Norte, Lisbon, Portugal; Faculdade de Medicina de Lisboa, Lisbon, Portugal

P10 Component-resolved IgE profiles in Georgian patients

Tamar Abramidze, Nino Lomidze, Maia Gotua

P11 Cross reactivity between food and pollen allergens in Lithuania according to spIgE evaluation

Austeja Dapkeviciute, Ruta Einikyte, Jolita Norkuniene, Laima Skrickiene, Asta Miskiniene, Violeta Kvedariene

P12 Distribution of inhalant allergy in the population of Lithuania

Ruta Einikyte, Austeja Dapkeviciute, Jolita Norkuniene, Laima Skrickiene, Asta Miskiniene, Violeta Kvedariene

Poster Session 2: Allergen molecules: identification, characterization, structure and function

P13 Interference of antigen 5-based cross-reactivity in the diagnosis of hymenoptera venom allergy

Maximilian Schiener, Bernadette Eberlein, Carmen Moreno-Aguilar, Gunilla Pietsch, Mareike Mc Intyre, Lea Schwarze, Dennis Rußkamp, Tilo Biedermann, Edzard Spillner, Ulf Darsow, Carsten Schmidt-Weber, Markus Ollert, Simon Blank

P14 IgE cross-reactivity between European Hymenoptera and Asian hornet (Vespa velutina) venom allergens

Cyril Longé, Andrea Brazdova, Jean-Louis Brunet, Claire Schwartz, Bruno Girodet, François Lavaud, Joelle Birnbaum, Nhân Pham Thi, Magalie Duchateau, Julia Chamot-Rooke, Laurence Guilloux, Marie-Ange Selva, Rémy Couderc, Hélène Sénéchal, Jean-Pierre Sutra, Pascal Poncet

P15 Carbohydrate composition of house dust mite extracts and major group 1 and group 2 allergens

Steffen Augustin, Linda Pump, Martin Wald, Thomas Eichhorn, Frank Fischer, Christoph Willers

P16 Specificity of monoclonal antibodies against cross-reactive carbohydrate determinants

Michaela Miehe, Melanie Plum, Sara Wolf, Frederic Jabs, Tim Raiber, Frank Bantleon, Henning Seismann, Thilo Jakob, Edzard Spillner

P17 Red meat allergic patients have a selective IgE response to the a-Gal glycan

Danijela Apostolovic, Anh Thu Tran, Sara Sanchez-Vidaurre, Tanja Cirkovic Velickovic, Maria Starkhammar, Carl Hamsten, Marianne Van Hage

P18 Specificity of non-specific lipid transfer proteins and influence of the ligands on their three-dimensional structure

Pawel Dubiela, Piotr Humeniuk, Sabine Pfeifer, Merima Bublin, Tomasz Borowski, Karin Hoffmann-Sommergruber

P19 Real-time PCR analysis of Pru av 1 and Pru av 3 allergens

Martie C.M. Verschuren, Shanna Bastiaan-Net, Defien Depoortere, Kay Foetisch, Stephan Scheurer, Harry J Wichers, Theo Noij

P20 Specificity of anti-Pru av 1 antibodies for the detection of Pru av 1 isoallergens

Martie C.M. Verschuren, Shanna Bastiaan-Net, Nikki M.E. Van Uden, Karel Vandenberghe, Kay Foetisch, Stephan Scheurer, Harry J. Wichers H.J., Theo H.M. Noij

P21 Enhancing recombinant production yield of Bet v 1 through codon usage harmonization

Anargyros Roulias, Maria Alejandra Parigiani, Heidi Hofer, Claudia Asam, Christof Ebner, Fátima Ferreira

P22 Structural and dynamic insights into the world of PR-10 allergens

Linda Ahammer, Sarina Grutsch, Martin Tollinger

Poster Session 3: Allergen molecules: identification, characterization, structure and function

P23 Purification of polcalcin from different pollen allergenic sources by antibody-affinity chromatography

Raquel Moya, Mª Angeles López-Matas, Raquel Reyes, Jerónimo Carnés

P24 Variations of wheat allergens in cultivars measured through a targeted quantitative mass spectrometry approach

Colette Larré, Hélène Rogniaux, Roberta Lupi, Sandra Denery-Papini

P25 Art v 1, Amb a 4 and Par h 1 defensin-like proteins share similar structural features but distinct immunological and allergenic properties

Isabel Maria Pablos, Stephanie Eichhorn, Yoan Machado, Peter Briza, Christof Ebner, Jung-Won Park, Alain Didierlaurent, Naveen Arora, Stefan Vieths, Gabriele Gadermaier, Fatima Ferreira

P26 Homogeneity or diversity of IgE-binding proteins in wheat dependant exercise induced anaphylaxis?

Sandra Denery-Papini, Charlene Tanaka, Florence Pineau, Roberta Lupi, Martine Drouet, Etienne Beaudouin, Martine Morisset, Susan Altenbach

P27 Deciphering the role of disulfide bonds and of repetitive epitopes in immunoglobulin E binding to wheat gliadins

Sandra Denery-Papini, Hamza Mameri, Chantal Brossard, Roberta Lupi, Florence Pineau, Jean Charles Gaudin, Denise Anne Moneret-Vautrin, Etienne Beaudouin, Evelyne Paty, Martine Drouet, Olivier Tranquet, Colette Larré

P28 Assessment of the allergenicity of soluble fractions from bread and durum wheats genotypes

Roberta Lupi, Stefania Masci, Olivier Tranquet, Denise-Anne Moneret-Vautrin, Sandra Denery-Papini, Colette Larré

P29 Isolation and characterization of Ara h 12 and Ara h 13: defensins, a novel class of peanut allergens

Skadi Kull, Arnd Petersen, Marisa Böttger, Sandra Rennert, Wolf-Meinhard Becker, Susanne Krause, Martin Ernst, Thomas Gutsmann, Johann Bauer, Buko Lindner, Uta Jappe

P30 Allergenicity attributes of different peanut market types

Stef Koppelman, Shyamali Jayasena, Dion Luykx, Erik Schepens, Danijela Apostolovic, Govardus De Jong, Tom Isleib, Julie Nordlee, Joe Baumert, Steve Taylor, Soheila Maleki

P31 The impact of peanut lipids on Ara h 1-induced immune responses in monocytes-derived dendritic cells

Chiara Palladino, Barbara Gepp, Sofía Sirvent, Alba Angelina, Merima Bublin, Christian Radauer, Nina Lengger, Thomas Eiwegger, Oscar Palomares, Heimo Breiteneder

P32 Compared allergenicity of native and thermally aggregated ovalbumin as large agglomerated particles

Mathilde Claude, Roberta Lupi, Grégory Bouchaud, Marie Bodinier, Chantal Brossard, Sandra Denery-Papini

P33 Simulation of the gastrointestinal digestion of the hazelnut allergens Cor a 9 and Cor a 11 by an in-vitro model and characterisation of peptidic products including epitopes by HPLC-MS/MS

Robin Korte, Julia Bräcker, Jens Brockmeyer

P34 Analysis of distribution of rice allergens in brown rice grain and allergenicity of the products containing rice bran

Rie Satoh, Reiko Teshima

Poster Session 4: Molecular approaches in AIT

P35 Production of a recombinant hypoallergenic variant of the major peanut allergen Ara h 2 for allergen-specific immunotherapy

Angelika Tscheppe, Dieter Palmberger, Merima Bublin, Christian Radauer, Chiara Palladino, Barbara Gepp, Nina Lengger, Reingard Grabherr, Heimo Breiteneder

P36 Mutagenesis of amino acids critical for calcium-binding leads to the generation of a hypoallergenic Phl p 7 variant

Marianne Raith, Linda Sonnleitner, Doris Zach, Konrad Woroszylo, Margit Focke-Tejkl, Herbert Wank, Thorsten Graf, Annette Kuehn, Ines Swoboda

P37 Are birch pollen allergen immunotherapy induced blocking antibodies protective for cross-reactive allergens?

Claudia Asam, Sara Huber, Heidi Hofer, Roland Lang, Thomas Hawranek, Fátima Ferreira, Michael Wallner

P38 High success of 58 subcutaneous immunotherapy for pets allergy in a polyallergic cohort of patients: a component resolved individually adapted treatment (CRIAT)

Fabienne Gay-Crosier

P39 Neutrophils are potential antigen presenting cells in IgE- mediated allergy

Dominika Polak, Birgit Nagl, Claudia Kitzmüller, Barbara Bohle

P40 Characterization of allergen-specific CD8+ T cells in type I allergy

Nazanin Samadi, Claudia Kitzmüller, Rene Geyeregger, Barbara Bohle, Beatrice Jahn-Schmid

Poster Session 5: Molecular and cellular diagnostic tests

P41 Nanofluidic-based biosensors allow quantification of total circulating IgE from a drop of blood in 5 minutes

Aurélie Buchwalder, Ariel Gomez, Fabien Rebeaud, Iwan Märki

P42 Allergen microarray for the analysis of serum IgE binding profile and allergenic activity

Jaana Haka, Liisa Hattara, Marika Heikkinen, Merja H Niemi, Juha Rouvinen, Petri Saviranta, Pekka Mattila, Kristiina Takkinen, Marja-Leena Laukkanen

P43 Generation of a well-characterized panel of periplaneta americana allergens for component resolved diagnosis

Stephanie Eichhorn, Isabel Pablos, Bianca Kastner, Bettina Schweidler, Sabrina Wildner, Peter Briza, Jung-Won Park, Naveen Arora, Stefan Vieths, Gabriele Gadermaier, Fatima Ferreira

P44 Improved diagnostic sensitivity of recombinant Api m 1 and Ves v 5 in diagnosis of Hymenoptera venom allergy

Mira Silar, Julij Selb, Rok Kogovsek, Mitja Kosnik, Peter Korosec

P45 Added value of biomarkers of primary sensitization and cross-reactivity in patients with hymenoptera venom allergy

Leticia Pestana, Alcinda Campos Melo, Ana Mendes, Maria Elisa Pedro, Manuel Pereira Barbosa, Maria Conceição Pereira Santos

P46 Cosensitization to Alt a 1 and Act d 2: more than a fortuitous association?

Françoise Bienvenu, Claire Goursaud, Lorna Garnier, Sandrine Jacquenet, Michaël Degaud, Sébastien Viel, Annick Barre, Pierre Rougé, Jacques Bienvenu, Joana Vitte

P47 Molecular diagnosis for peanut allergy: ALFA method performs as well as established methods for Ara h 1, Ara h 2, Ara h 6, Ara h 9 and CCD

Amel Bensalah, Isabelle Cleach, Laurent Mousseau, Chantal Agabriel, Valérie Liabeuf, Joëlle Birnbaum, Jean-Louis Mège, Joana Vitte

P48 Evaluation of a food challenge service in relation to specific IgE to molecular components in children with suspected peanut allergy

James Gardner, Minal Gandhi, Harsha Kariyawasam, Giuseppina Rotiroti

P49 Component resolved diagnosis in cereal allergy

Isabel Carrapatoso, Celso Pereira, Frederico Regateiro, Emília Faria, Ana Todo-Bom

Poster Session 6: Molecular diagnosis in prevention and therapy

P50 Pretreatment molecular sensitizations determine the sIgG4 induction during the updosing of SCIT and may be useful to identify clinically relevant additional sensitizations

Johannes Martin Schmid, Ronald Dahl, Hans Juergen Hoffmann

P51 Usefulness of recombinant latex allergens in immunotherapy’s decision and follow-up

Inês Mota, Filipe Benito Garcia, Angela Gaspar, Mário Morais-Almeida

P52 Omega-5-gliadin in the diagnosis of wheat-dependent anaphylaxis induced by ibuprofen but not by exercise

Joana Cosme, Letícia Pestana, Amélia Spínola Santos, Manuel Pereira Barbosa

P53 Food dependent exercise-induced anaphylaxis: a component-resolved and in vitro depletion approach to access IgE cross-reactivity

Diana Silva, Teresa Vieira, Ana Maria Pereira, André Moreira, Luís Delgado

P54 Olive pollen allergens: what are we missing?

Sara Prates, Cátia Alves, Elena Finelli, Paula Leiria Pinto

P55 Purified Alt a 1 extract in Alternaria alternata allergy diagnosis

Bárbara Kong Cardoso, Cíntia Cruz, Filipa Semedo, Elza Tomaz, Filipe Inácio

P56 Use of specific IgE Bos d8 (casein) to aid early introduction of dietary baked milk in children with cows’ milk allergy

James Gardner, Santanu Maity, Giuseppina Rotiroti, Minal Gandhi

P57 Molecular characterisation and immunoreactivity of a peanut ingredient for use in oral food challenges

Ivona Baricevic-Jones, Justin T. Marsh, Phil E. Johnson, Anuradha Balasundaram, Anya-May Hope, Aafke Taekema, Angela Simpson, Aida Semic-Jusufagic, E.N. Clare Mills

P58 Specific IgE to recombinant allergens of hazelnut and oral food challenge in children

Gourdon Dubois Nelly, Sellam Laetitia, Pereira Bruno, Michaud Elodie, Messaoudi Khaled, Evrard Bertrand, Fauquert Jean-Luc

Poster session 7/8: miscellaneous

P59 What defines a protein as an allergen? A discussion of sources and sufficiency

Richard E. Goodman

P60 Cat allergy: relationship between clinical and molecular diagnostic

María Cecilia Martín Fernández De Basoa, Antón Fernández Ferreiro, Elena Rodríguez Plata

P61 Anaphylaxis to rabbit: the cat came in last

Luis Amaral, Borja Bartolomé, Alice Coimbra, Jose L Placido

P62 Dog allergy: relationship between clinical and molecular diagnostic

María Cecilia Martín Fernández De Basoa, Antón Fernández Ferreiro, Elena Rodríguez Plata

P63 Correlation of serum timothy grass-pollen specific IgE levels determined by two immunoblot test systems

Mariana Vieru, Florin-Dan Popescu, Florin-Adrian Secureanu, Carmen Saviana Ganea

P64 Development of oral food challenge formulations for diagnosis of fish allergy using powdered fish ingredients

Carol Ann Costello, Ivona Baricevic-Jones, Martin Sorensen, Clare Mills, Adrian Rogers, Aage Otherhals

P65 Fish and peanut allergens interact with plasma membranes of intestinal and bronchial epithelial cells and induce differential gene expression of cytokines and chemokines

Tanja Kalic, Isabella Ellinger, Chiara Palladino, Barbara Gepp, Eva Waltl, Verena Niederberger-Leppin, Heimo Breiteneder

P66 Interleukin 4 affects fat tissue metabolism and expression of pro-inflammatory factors in isolated rat adipocytes

Dawid Szczepankiewicz, Ewa Pruszynska-Oszmalek, Marek Skrzypski, Krzysztof W. Nowak, Aleksandra Szczepankiewicz

P67 Ozone induced airway hyperreactivity in PD-L2−/− mice model

Gwang-Cheon Jang

P68 Thymic stromal lymphopoietin (TSLP) and its receptor as targets for the development of anti-inflammatory inhibitory agents

Iva Markovic, Andreas Borowski, Tina Vetter, Andreas Wohlmann, Michael Kuepper, Karlheinz Friedrich

P69 The mononuclear phagocyte system in experimentally-induced allergic rhinitis

Ibon Eguiluz Gracia, Anthony Bosco, Ralph Dollner, Guro Reinholt Melum, Anya C Jones, Maria Lexberg, Patrick G Holt, Espen Sønderaal Bækkevold, Frode Lars Jahnsen

P70 Expression of histamine metabolizing enzymes is increased in allergic children

Aleksandra Szczepankiewicz, Paulina Sobkowiak, Marta Rachel, Beata Narozna, Dorota Jenerowicz, Witold Swiatowy, Anna Breborowicz

P71 Modifying the glycosylation of human IgE towards oligomannosidic structures does not affect its biological activity

Melanie Plum, Sara Wolf, Frank Bantleon, Henning Seismann, Frederic Jabs, Michaela Miehe, Thilo Jakob, Edzard Spillner

P72 Flying Labs: an educational initiative to transfer allergy research into high-school settings

Michael Wallner, Heidi Hofer, Fatima Ferreira, Reinhard Nestelbacher

P73 Clinical significance of antihistamines and Kujin, an anti-allergic Kampo medicine

Hiroyuki Fukui

Standardization of allergen products: 3. Validation of candidate European Pharmacopoeia standard methods for quantification of major birch allergen Bet v 1

BACKGROUND

The BSP090 project aims at establishing European Pharmacopoeia Reference Substances in combination with the corresponding ELISA methods for the quantification of major allergens in allergen products. Two sandwich ELISAs proved suitable for quantification of Bet v 1, the major birch pollen allergen, in preceding phases of BSP090.

METHODS

Two Bet v 1-specific ELISA systems were compared with respect to accuracy and precision in a ring trial including 13 laboratories. Model samples containing recombinant rBet v 1.0101 as well as native birch pollen extracts were measured independently at least three times in each facility. The assessment was completed with a comparative quantification of Bet v 1 in 30 marketed birch allergen products in one laboratory, simulating the future use as reference method.

RESULTS

In the collaborative study, both candidate ELISAs confirmed their suitability to quantify recombinant and native Bet v 1. ELISA-A showed higher precision and lower interlaboratory variability, yet ELISA-B exhibited slightly higher accuracy. Subsequent parallel measurement of Bet v 1 in a panel of 'real-life' birch allergen products indicated better repeatability of ELISA-B. Both systems detected substantial differences in Bet v 1 content between allergen products, but the effect was more pronounced using ELISA-B due to persistently higher values compared to ELISA-A.

CONCLUSIONS

In the collaborative study, no deciding differences were observed between the two candidate ELISAs. Further comparison under conditions simulating the intended use combined with the criterion of long-term availability enabled the selection of one Bet v 1-specific ELISA for proposal as European Pharmacopoeia standard method.

Biomarkers for Allergen Immunotherapy: A "Panoromic" View

Biomarkers (BMKs) are biological parameters that can be measured to predict or monitor disease severity or treatment efficacy. The induction of regulatory dendritic cells (DCs) concomitantly with a downregulation of proallergic DC2s (ie, DCs supporting the differentiation of T-helper lymphocyte type 2 cells) in the blood of patients allergic to grass pollen has been correlated with the early onset of allergen immunotherapy efficacy. The combined use of omics technologies to compare biological samples from clinical responders and nonresponders is being implemented in the context of nonhypothesis-driven approaches. Such comprehensive "panoromic" strategies help identify completely novel candidate BMKs, to be subsequently validated as companion diagnostics in large-scale clinical trials.

Allergen immunotherapy for birch pollen-allergic patients: recent advances

As of today, allergen immunotherapy is performed with aqueous natural allergen extracts. Recombinant allergen vaccines are not yet commercially available, although they could provide patients with well-defined and highly consistent drug substances. As Bet v 1 is the major allergen involved in birch pollen allergy, with more than 95% of patients sensitized to this allergen, pharmaceutical-grade recombinant Bet v 1-based vaccines were produced and clinically tested. Herein, we compare the clinical results and modes of action of treatments based on either a birch pollen extract or recombinant Bet v 1 expressed as hypoallergenic or natural-like molecules. We also discuss the future of allergen immunotherapy with improved drugs intended for birch pollen-allergic patients suffering from rhinoconjunctivitis.

Structural and Functional Characterization of the Major Allergen Amb a 11 from Short Ragweed Pollen

Allergy to the short ragweed (Ambrosia artemisiifolia) pollen is a major health problem. The ragweed allergen repertoire has been recently expanded with the identification of Amb a 11, a new major allergen belonging to the cysteine protease family. To better characterize Amb a 11, a recombinant proform of the molecule with a preserved active site was produced in Escherichia coli, refolded, and processed in vitro into a mature enzyme. The enzymatic activity is revealed by maturation following an autocatalytic processing resulting in the cleavage of both N- and C-terminal propeptides. The 2.05-Å resolution crystal structure of pro-Amb a 11 shows an overall typical C1A cysteine protease fold with a network of molecular interactions between the N-terminal propeptide and the catalytic triad of the enzyme. The allergenicity of Amb a 11 was confirmed in a murine sensitization model, resulting in airway inflammation, production of serum IgEs, and induction of Th2 immune responses. Of note, inflammatory responses were higher with the mature form, demonstrating that the cysteine protease activity critically contributes to the allergenicity of the molecule. Collectively, our results clearly demonstrate that Amb a 11 is a bona fide cysteine protease exhibiting a strong allergenicity. As such, it should be considered as an important molecule for diagnosis and immunotherapy of ragweed pollen allergy.

Patterns of IgE sensitization in house dust mite-allergic patients: implications for allergen immunotherapy

BACKGROUND

Understanding patterns of IgE sensitization in Dermatophagoides-allergic patients living in various geographical areas is necessary to design a product suitable for worldwide allergen immunotherapy (AIT).

METHODS

Using a HIFI Allergy customized microarray assay, IgEs specific for 12 purified allergens from Dermatophagoides pteronyssinus or D. farinae were assessed in sera from 1302 house dust mite (HDM)-allergic patients living in various areas. Comprehensive mass spectrometric (MS) analyses were conducted to characterize HDM extracts, as well as purified bodies and feces.

RESULTS

Patterns of IgE reactivity to HDM allergens are comparable in all cohorts of patients analyzed, encompassing adults and 5- to 17-year-old children, as well as American, Canadian, European, and Japanese patients. Overall, >70% and >80% of HDM-allergic patients are sensitized to group 1 and group 2 allergens, respectively, from D. pteronyssinus and/or D. farinae species. Furthermore, 20-47% of patients also have IgEs to allergens from groups 4, 5, 7, 13, 15, 21, and 23. All patients have IgEs to allergens present in mite bodies and feces. MS-based analyses confirmed the presence of mite allergens recorded by IUIS in D. pteronyssinus and D. farinae extracts, with groups 2, 8, 10, 11, 14, and 20 prominent in bodies and groups 1, 6, 18, and 23 well represented in feces.

CONCLUSIONS

Mite-specific AIT should rely upon a mixture of D. pteronyssinus and D. farinae extracts, manufactured from both feces and bodies. Such a combination is appropriate to treat children and adult Dermatophagoides-allergic patients from Asia, Europe, and North America.

Relevance of a 5-grass sublingual tablet for immunotherapy of patients with grass pollen allergy in North America

Grass pollen allergy is common and clinically consequential in North America. While it is frequently treated with subcutaneous or sublingual immunotherapy, debate remains regarding whether allergen immunotherapy is best carried out using a single representative or multiple cross-reactive allergen(s). Patients are commonly exposed to pollens from multiple allergenic grass species belonging to the Pooideæ subfamily. Beyond the known IgE cross-reactivity, considerable molecular heterogeneity exists with respect to allergen content among grass species, with further evidence that these molecular variants can be detected by the patients' immune system. These observations provide a compelling scientific rationale for the use of mixed pollen allergen extracts to broaden the allergen repertoire, with the aim of reorienting inappropriate immune responses in allergic patients.

Allergen extracts for immunotherapy: to mix or not to mix?

Allergen immunotherapy (AIT) is established as a curative treatment for allergic rhinitis, asthma, as well as insect venom allergy. AIT is based on the administration of natural allergen extracts via the subcutaneous or sublingual routes to reorient the immune system towards tolerogenic mechanisms. In this regard, since many patients are poly-allergic, mixtures of allergen extracts are often used with a potential risk to cause allergen degradation, thereby affecting treatment efficacy. Herein, we discuss the advantages and drawbacks of mixing homologous (i.e., related) or heterogeneous (i.e., unrelated) allergen extracts. We provide evidence for incompatibilities between mixes of grass pollen and house dust mite extracts containing bodies and feces, and summarize critical points to consider when mixing allergen extracts for AIT.

Changes in markers associated with dendritic cells driving the differentiation of either TH2 cells or regulatory T cells correlate with clinical benefit during allergen immunotherapy

BACKGROUND

Regulatory dendritic cell (DC) markers, such as C1Q, are upregulated in PBMCs of patients with grass pollen allergy exhibiting clinical benefit during allergen immunotherapy (AIT).

OBJECTIVES

We sought to define markers differentially expressed in human monocyte-derived DCs differentiated toward a proallergic (DCs driving the differentiation of TH2 cells [DC2s]) phenotype and investigate whether changes in such markers in the blood correlate with AIT efficacy.

METHODS

Transcriptomes and proteomes of monocyte-derived DCs polarized toward DCs driving the differentiation of TH1 cells (DC1s), DC2s, or DCs driving the differentiation of regulatory T cells (DCreg cells) profiles were compared by using genome-wide cDNA microarrays and label-free quantitative proteomics, respectively. Markers differentially regulated in DC2s and DCreg cells were assessed by means of quantitative PCR in PBMCs from 80 patients with grass pollen allergy before and after 2 or 4 months of sublingual AIT in parallel with rhinoconjunctivitis symptom scores.

RESULTS

We identified 20 and 26 new genes/proteins overexpressed in DC2s and DCreg cells, respectively. At an individual patient level, DC2-associated markers, such as CD141, GATA3, OX40 ligand, and receptor-interacting serine/threonine-protein kinase 4 (RIPK4), were downregulated after a 4-month sublingual AIT course concomitantly with an upregulation of DCreg cell-associated markers, including complement C1q subcomponent subunit A (C1QA), FcγRIIIA, ferritin light chain (FTL), and solute carrier organic anion transporter family member 2B1 (SLCO2B1), in the blood of clinical responders as opposed to nonresponders. Changes in such markers were better correlated with clinical benefit than alterations of allergen-specific CD4(+) T-cell or IgG responses.

CONCLUSIONS

A combination of 5 markers predominantly expressed by blood DCs (ie, C1Q and CD141) or shared with lymphoid cells (ie, FcγRIIIA, GATA3, and RIPK4) reflecting changes in the balance of regulatory/proallergic responses in peripheral blood can be used as early as after 2 months to monitor the early onset of AIT efficacy.

Focusing the mechanism of action to dissect the different treatments of respiratory allergy

The treatment of respiratory allergy is based on several drugs with different mechanisms of action, which encompass an effect only on symptoms, limited factors of inflammation or the whole process of inflammation. Dissecting the different treatments by their mechanism of action is relevant for the management of allergic patients. Corticosteroids, administered as nasal sprays in rhinitis or by inhalation devices in asthma, and allergen immunotherapy (AIT) are the most effective treatments for respiratory allergy, achieving the control on inflammation by a number of cellular and molecular mechanisms. What distinguishes corticosteroids from AIT is the duration of clinical outcomes that ends with treatment withdrawal for the former but persists after stopping for AIT, due to its disease-modifying effect.

Development and evaluation of a sublingual tablet based on recombinant Bet v 1 in birch pollen-allergic patients

BACKGROUND

Sublingual immunotherapy (SLIT) applied to type I respiratory allergies is commonly performed with natural allergen extracts. Herein, we developed a sublingual tablet made of pharmaceutical-grade recombinant Bet v 1.0101 (rBet v 1) and investigated its clinical safety and efficacy in birch pollen (BP)-allergic patients.

METHODS

Following expression in Escherichia coli and purification, rBet v 1 was characterized using chromatography, capillary electrophoresis, circular dichroism, mass spectrometry and crystallography. Safety and efficacy of rBet v 1 formulated as a sublingual tablet were assessed in a multicentre, double-blind, placebo-controlled study conducted in 483 patients with BP-induced rhinoconjunctivitis.

RESULTS

In-depth characterization confirmed the intact product structure and high purity of GMP-grade rBet v 1. The crystal structure resolved at 1.2 Å documented the natural conformation of the molecule. Native or oxidized forms of rBet v 1 did not induce the production of any proinflammatory cytokine by blood dendritic cells or mononuclear cells. Bet v 1 tablets were well tolerated by patients, consistent with the known safety profile of SLIT. The average adjusted symptom scores were significantly decreased relative to placebo in patients receiving once daily for 5 months rBet v 1 tablets, with a mean difference of 17.0-17.7% relative to the group treated with placebo (P < 0.025), without any influence of the dose in the range (12.5-50 μg) tested.

CONCLUSION

Recombinant Bet v 1 has been produced as a well-characterized pharmaceutical-grade biological drug. Sublingual administration of rBet v 1 tablets is safe and efficacious in patients with BP allergic rhinoconjunctivitis.

Specific IgE recognition of pollen allergens from subtropic grasses in patients from the subtropics

BACKGROUND

Pollens of subtropical grasses, Bahia (Paspalum notatum), Johnson (Sorghum halepense), and Bermuda (Cynodon dactylon), are common causes of respiratory allergies in subtropical regions worldwide.

OBJECTIVE

To evaluate IgE cross-reactivity of grass pollen (GP) found in subtropical and temperate areas.

METHODS

Case and control serum samples from 83 individuals from the subtropical region of Queensland were tested for IgE reactivity with GP extracts by enzyme-linked immunosorbent assay. A randomly sampled subset of 21 serum samples from patients with subtropical GP allergy were examined by ImmunoCAP and cross-inhibition assays.

RESULTS

Fifty-four patients with allergic rhinitis and GP allergy had higher IgE reactivity with P notatum and C dactylon than with a mixture of 5 temperate GPs. For 90% of 21 GP allergic serum samples, P notatum, S halepense, or C dactylon specific IgE concentrations were higher than temperate GP specific IgE, and GP specific IgE had higher correlations of subtropical GP (r = 0.771-0.950) than temperate GP (r = 0.317-0.677). In most patients (71%-100%), IgE with P notatum, S halepense, or C dactylon GPs was inhibited better by subtropical GP than temperate GP. When the temperate GP mixture achieved 50% inhibition of IgE with subtropical GP, there was a 39- to 67-fold difference in concentrations giving 50% inhibition and significant differences in maximum inhibition for S halepense and P notatum GP relative to temperate GP.

CONCLUSION

Patients living in a subtropical region had species specific IgE recognition of subtropical GP. Most GP allergic patients in Queensland would benefit from allergen specific immunotherapy with a standardized content of subtropical GP allergens.

Identification of the cysteine protease Amb a 11 as a novel major allergen from short ragweed

BACKGROUND

Allergy to pollen from short ragweed (Ambrosia artemisiifolia) is a serious and expanding health problem in the United States and in Europe.

OBJECTIVE

We sought to investigate the presence of undescribed allergens in ragweed pollen.

METHODS

Ragweed pollen proteins were submitted to high-resolution gel electrophoresis and tested for IgE reactivity by using sera from 92 American or European donors with ragweed allergy. Pollen transcriptome sequencing, mass spectrometry (MS), and recombinant DNA technologies were applied to characterize new IgE-binding proteins.

RESULTS

High-resolution IgE immunoblotting experiments revealed that 50 (54%) of 92 patients with ragweed allergy were sensitized to a 37-kDa allergen distinct from Amb a 1. The full-length cDNA sequence for this molecule was obtained by means of PCR cloning after MS sequencing of the protein combined with ragweed pollen RNA sequencing. The purified allergen, termed Amb a 11, was fully characterized by MS and confirmed to react with IgEs from 66% of patients. This molecule is a 262-amino-acid thiol protease of the papain family expressed as a combination of isoforms and glycoforms after proteolytic removal of N- and C-terminal propeptides from a proform. Three-dimensional modeling revealed a high structural homology with known cysteine proteases, including the mite Der p 1 allergen. The protease activity of Amb a 11, as well as its capacity to activate basophils from patients with ragweed allergy, were confirmed. The production of a nonglycosylated recombinant form of Amb a 11 in Escherichia coli established that glycosylation is not required for IgE binding.

CONCLUSION

We identified the cysteine protease Amb a 11 as a new major allergen from ragweed pollen. Given the similar physicochemical properties shared by the 2 major allergens, we hypothesize that part of the allergenic activity previously ascribed to Amb a 1 is rather borne by Amb a 11.

Characterization of oral immune cells in birch pollen-allergic patients: impact of the oral allergy syndrome and sublingual allergen immunotherapy on antigen-presenting cells

BACKGROUND

A detailed characterization of human oral immune cells is needed to better understand local mechanisms associated with allergen capture following oral exposure.

METHODS

Oral immune cells were characterized by immunohistology and immunofluorescence in biopsies obtained from three healthy individuals and 23 birch pollen-allergic patients with/without oral allergy syndrome (OAS), at baseline and after 5 months of sublingual allergen immunotherapy (AIT).

RESULTS

Similar cell subsets (i.e., dendritic cells, mast cells, and T lymphocytes) were detected in oral tissues from healthy and birch pollen-allergic individuals. CD207+ Langerhans cells (LCs) and CD11c+ myeloid dendritic cells (DCs) were found in both the epithelium and the papillary layer of the Lamina propria (LP), whereas CD68+ macrophages, CD117+ mast cells, and CD4+ /CD8+ T cells were rather located in both the papillary and reticular layers of the LP. Patterns of oral immune cells were identical in patients with/without OAS, except lower numbers of CD207+ LCs found in oral tissues from patients with OAS, when compared to OAS- patients (P < 0.05). A 5-month sublingual AIT had a limited impact on oral immune cells, with only a significant increase in IgE+ cells in patients from the active group. Colocalization experiments confirmed that such IgE-expressing cells mostly encompass CD68+ macrophages located in the LP, and to a lesser extent CD207+ LCs in the epithelium.

CONCLUSION

Two cell subsets contribute to antigen/allergen uptake in human oral tissues, including (i) CD207+ LCs possibly involved in the physiopathology of OAS and (ii) CD68+ macrophages likely critical in allergen capture via IgE-facilitated mechanisms during sublingual AIT.