First Peanut (Arachis hypogaea) Allergen Oral Immunotherapy product out of sale – a major drawback for food allergy immunotherapy?

Ancestry-associated immune signalling differences in atopic dermatitis and dupilumab treatmentDuan Ni1,2,3,4, Ralph Nanan1,2,3*1 Sydney Medical School Nepean, The University of Sydney, Sydney, NSW, Australia2 Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia3 Nepean Hospital, Nepean Blue Mountains Local Health District, Sydney, NSW, Australia4 Sydney Infectious Disease Institute, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia*Correspondence:Ralph Nananralph.nanan@sydney.edu.auSydney Medical School Nepean, The University of Sydney.Nepean Hospital, Level 5, South Block, Penrith NSW, 2751, AustraliaTelephone: +61 2 4734 1614Fax: +61 2 4734 1144

Structural determination of a human IgE epitope on major birch allergen Bet v 1Andrea O’Malley1, Brooke T. Borders2,3, Jeffrey M. Wilson3, Scott A. Smith2,3, Maksymilian Chruszcz11Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA.2Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, 37232, USA.3Division of Asthma, Allergy, and Clinical Immunology, University of Virginia School of Medicine, Charlottesville, Virginia, 22903, USA.Funding: This work was supported by a research grant from NIH/National Institute of Allergy and Infectious Disease R01AI155668 (to SAS).

Title: Association between interleukin-13 inhibitors with risk of atopic dermatitis related neuropsychiatric comorbidities

Allergen immunotherapy (AIT) is the only disease-modifying therapeutic approach for cat allergy, though it requires at least three years of treatment and can potentially induce severe systemic reactions. Plant-derived bioparticles expressing Fel d 1 allergen (Fel d 1 eBP) have been developed as a novel therapeutic candidate for cat allergy. Cellular and scRNA-seq analyses reveal that Fel d 1 eBP induce Th1 and IL-10 + T cells. We also demonstrate that Fel d 1 eBP targets the induction of protective metallothionine genes, CCL18 + monocytes and naïve B cells that are interferon responsive. Moreover, Fel d 1 eBP demonstrated reduced capacity to elicit basophil activation and histamine release, indicating their hypoallergenic nature. Administration of titrated doses of Fel d 1 eBP through skin prick test revealed that they are well-tolerated with reduced mean wheal compared to native Fel d 1 in open-label Phase 0 study. Altogether, we demonstrate that Fel d 1 eBP is hypo-allergenic and demonstrate tolerogenic properties making them a novel candidate for use in AIT for cat allergy.

Title: Low-Dose Intralymphatic Immunotherapy for Grass Pollen Allergy is Both Safe and Effective

Monocyte chemotactic factors in the airways of patients with mild asthma before and after an allergen challengeTo the Editor,Allergic asthma is characterized by eosinophilic airway inflammation in the majority of subjects, but a number of individuals, especially subjects with severe asthma, may have primarily neutrophilic inflammation. Recent murine studies suggest that blood monocytes (Mo) facilitate eosinophil and neutrophil recruitment to the lungs (1, 2) and their depletion decreases airway inflammation and hyperresponsiveness. However, we know little about the role of Mo in human asthma. Induced sputum from patients with asthma has increased numbers of Mo compared to healthy controls (3), while Mo in the airways correlate with other indicators of inflammation (4). The triggers for Mo recruitment to the airways are not clearly understood. In this study we measured the presence of Mo chemotactic factors in the airways of mild asthmatics before and after an allergen challenge, and developed an ex vivo assay to understand their biological significance.We analyzed monocyte chemotactic factors in induced sputum from 15 mild asthmatics before and 24 h after allergen challenge, with ethics approval and informed consent (Supplemental Table 1). The % of eosinophils significantly increased 24h after allergen challenge, while other immune cell counts remained unchanged (Supplemental Fig. 1). CCL2, CCL3, CCL4, CCL13, CCL17 and CCL22 were detected in induced sputum, but only CCL4 and CCL17 levels significantly increased at 24h compared to baseline (Fig. 1A &1B and supplemental Fig. 2); the CCL17 increase was evident only in subjects with dual responses to allergen challenge and not those with isolated early response (Fig. 1C & 1D).To test the biological significance of Mo chemotactic factors in induced sputum, we developed a Mo chemotactic assay using peripheral blood mononuclear cells (PBMC) from healthy volunteers stimulated with sputum supernatants from asthmatic subjects; migrating Mo were identified among migrating PBMC by flow cytometry (gating strategy in supplemental Fig. 3). Increasing dilutions of sputum supernatants mediated a chemotaxis dose response (supplemental Fig. 4A) but not chemokinesis (supplemental Fig. 4B). Sputum supernatants preferentially attracted Mo; the proportion of Mo increased from 3.6% (2.37–6.82%) in the initial PBMC population to 13.6% (6.9–18.06%) among cells that migrated in response to 24h post-allergen challenge sputum, while lymphocytes decreased from 95.15% (92.9–96.6%) to 85.0% (80.6–86.6%) (supplemental Fig. 5A and 5B). In 24 independent experiments, with each induced sputum sample tested at least once, we observed significantly increase in both the numbers of migrating Mo (Fig. 2A), and the % of total seeded Mo that migrated (Fig. 2B), toward 24h sputum supernatants compared to pre-challenge supernatants (p = 0.008 & p=0.028 respectively). Sputum supernatants also exhibited measurable lymphocyte chemotactic activity, but lymphocyte chemotaxis was not different between pre and 24h post-challenge supernatants (Fig. 2C and D).To start understanding the factors mediating Mo chemotaxis we tested a CCR4 antagonist to block the effects of CCL17 and a CCR2/CCR5 antagonist to block the effect of CCL4. Both the CCR4 antagonist C021 (0.14 µM, equal to IC50; Fig. 2E) and the dual CCR2/CCR5 antagonist TAK-779 (27 nM, equal to IC50; Fig. 2F), inhibited Mo chemotaxis towards 24h sputum supernatants (n=12). The two antagonists together had slightly increased effect (supplemental Fig. 6).Our findings demonstrate that induced sputum from patients with mild asthma following allergen challenge enhances Mo chemotaxis, likely driven by increased CCL4 and CCL17 levels, though the involvement of additional factors cannot be ruled out. Other evidence also shows elevated levels of Mo chemotactic factors, such as CCL13 and CCL4, in the airways of patients with asthma (5, 6) supporting the notion of Mo accumulation contributing to airway inflammation. Further research is required to understand whether these chemotactic factors are associated with variations in asthma severity and/or control.Authors’ name and affiliation: Nami Shrestha Palikhe1, Yingqi Wu1, Karen J. Howie2, Caitlin Stevens2, Jennifer Mitchell 2 Lesley Wiltshire2, Gail M, Gauvreau 2 Harissios Vliagoftis 11 Department of Medicine and Alberta Respiratory Centre, University of Alberta, and 2Department of Medicine, McMaster UniversityCorrespondence : Harissios Vliagoftis (hari@ualberta.ca) /Nami Shrestha Palikhe (nami@ualberta.ca)Funding Source : This research was supported by grant funding to HV from CIHR (133475) and the GlaxoSmithKline–CIHR Research Chair in Airway Inflammation (143901).Conflict of Interest : The authors declare that they have no competing interests in this section.

Background: Gut microbiota and their metabolites play a key role in digestive dysimmunity and tolerance breakdown, leading to pathologies such as food protein-induced enterocolitis syndrome (FPIES). This study aimed to compare both gut and salivary microbiota over time between allergic and tolerant patients and matched controls. Methods Faecal and salivary samples were collected longitudinally from FPIES allergic patients on an elimination diet, and after their natural tolerance acquisition, and from matched controls (1:1 ratio). 16S rRNA gene sequencing and biostatistical analyses (ALDEx2, ANCOM-BC, DESeq2, LEfSe, MaAsLIN2) were used to compare microbiota composition between groups. The measurement of faecal short-chain fatty acids (SCFAs) (gas chromatography) evaluated gut microbiota functions. Results Thirty-eight allergic patients were included (median age: 1.3 years), and 22 became tolerant over time. Allergic patients exhibited lower gut and salivary alpha-diversities, and several different genera (12 in stools including less Ruminococcus, 2 in saliva), and higher relative abundance of acetate than controls. With tolerance acquisition, faecal alpha-diversities partially increased, whereas SCFAs normalized. Ultimately, there were more differences in faecal and salivary microbiota in allergic patients vs. after tolerance acquisition (i.e. more Blautia, Ruminococcus, Faecalibacterium, Prevotella-9, and less Escherichia- Shigella in tolerant patients) than between controls over time. Conclusion The faecal and salivary dysbiosis observed in allergic patients with FPIES partially resolved after tolerance acquisition. Understanding the underlying mechanisms of dysbiosis is crucial to prevent and help manage FPIES. A prolonged follow-up could determine if dysbiosis resolution would be complete, and if this early infancy dysbiosis has long-term consequences on health.

The double-blind placebo-controlled oral food challenge (DBPCFC) has been the “gold standard” for diagnosing IgE-mediated food allergy for the past 50 years. Despite tremendous strides in our understanding of basic mechanisms and clinical features of food allergy, we remain dependent on refinements of old technologies, i.e. skin tests and serum IgE measurements, to complement clinical history in making an accurate diagnosis of food allergies. However, recent technical advances in two effector cell assays, i.e. the basophil and mast cell activations tests, may soon bring these diagnostic biomarkers to the clinic. In addition, new advances in antibody assays, T-cell assays, transcriptomics, and metabolomics in conjunction with machine learning and artificial intelligence may soon enable us to diagnose food allergy and accurately monitor immunotherapeutic outcomes without the need for an oral food challenge.

Background: A complex interaction between environmental and lifestyle factors, immune dysregulation, and skin barrier integrity is believed to contribute to the development of atopic dermatitis (AD). However, the precise mechanisms underlying disease onset in infants remain largely unclear. Methods: The ‘Munich Atopic Prediction Study’ (MAPS) is a comprehensive clinical and laboratory investigation of a prospective birth cohort from Munich, Germany. Information on pregnancy, child development, environmental influences, parental exposure to potential allergens, as well as illnesses affecting both children and parents is gathered through questionnaires. This is complemented by thorough clinical examinations conducted by trained dermatologists, with a focus on allergies and skin health. Biomarker analyses were performed on cord blood immune cells using flow cytometry. Results: Our analysis revealed an altered immune profile in the cord blood of infants who later developed AD, characterized by reduced frequencies of CD4 + T cells and increased B cell counts. Remarkably, however, regulatory B (Breg) cell frequencies were significantly reduced in these infants. Furthermore, our findings suggested that maternal allergen-specific immunotherapy may have a beneficial effect on the development and frequency of Breg cells. Conclusion: Our study identifies early immune alterations, particularly a reduction in cord blood Breg cells, as potential contributors to AD pathogenesis. These findings demand further research on B cells in the development of atopic diseases as B cells may participate in the initiation or prevention of these diseases. Specifically, inclusion of Breg cell measurements in neonatal immune panels could support early risk stratification and perceptively even personalized prevention of atopic diseases.

Age-related increase in anaphylaxis severity is associated with enhanced sensitivity to allergic mediatorsTo the Editor,Anaphylactic shock is the most severe outcome of an immunoglobulin E (IgE)-mediated allergy. This potentially life-threatening reaction with multi-organ involvement is characterized by a rapid hypersensitivity response to allergen exposure. Despite the well-documented general decline in immune cell function associated with aging, referred to as immunosenescence (1), older adults often experience more severe allergic reactions as compared to younger patients (2,3). Given the rising incidence of severe anaphylaxis (4) in conjunction with the rapidly growing elderly population (5), we sought to investigate the underlying mechanisms contributing to this age-related increase in allergy severity.First, we investigated whether the age-related increase in anaphylaxis severity that has been observed in humans is reproducible in mice. For this purpose, we passively sensitized young and aged C57BL/6 wild type (WT) mice intravenously with 2,4,6-trinitrophenyl (TNP)-specific IgE (clone: MEB-38), followed by intraperitoneal challenge with TNP-ovalbumin conjugate (TNP-OVA) on the next day (Figure 1A). Indeed, aged mice exhibited significantly stronger anaphylactic responses, evidenced by greater loss in body temperature (Figure 1B) and a larger area under the hypothermia curve (AUC) (Figure 1C). To our surprise, serum levels of allergic effector cell-related mediators including histamine and mMCP-1 showed no significant differences between age groups (Figure 1D and E).To further confirm these findings, we used humanized FcεRIα (huFcεRIα) mice sensitized with equal amounts of 4-hydroxy-3-iodo-5-nitrophenylacetyl (NIP)-specific human IgE (clone: JW8) followed by intraperitoneal challenge with NIP-bovine serum albumin conjugate (NIP-BSA) on the next day (Figure 1F). The pattern of exaggerated anaphylaxis in aged mice was consistent, with increased body core temperature loss and AUC values (Figure 1G and H). Further analysis of allergic effector cell mediator levels (histamine and mMCP-1) again showed no age-related differences (Figure 1I and J).To explore potential contributors to increased anaphylaxis severity in aged mice, we additionally quantified basophil cell numbers and the amount of NIP-BSA-specific IgE on blood basophils before antigen challenge. Interestingly, aged mice showed neither increased blood basophil counts nor higher IgE levels on these cells (Figure 1K and L). In contrast, the amount of NIP-BSA-specific IgE on blood basophils was significantly lower in aged compared to young mice (Figure 1L), whileex vivo sensitization with exogenous IgE exhibited comparable IgE loading on blood basophils from young and aged mice, indicating that the reduced in vivo IgE binding was not due to differences in available high-affinity IgE receptor levels on these cells (Figure 1M).To further evaluate potential age-related changes in allergic effector cell behavior, we cultured bone marrow-derived mast cells (BMMCs) from young and aged WT and huFcεRIα mice and assessed their degranulation capacity in vitro . Aged BMMCs sensitized with JW8-IgE, Sus11-IgE or MEB38-IgE and challenged either in an antigen-dependent (NIP-BSA/TNP-OVA) or -independent (anti-IgE antibody Le27) way unexpectedly showed reduced activation levels as compared to young BMMCs as measured by surface levels of the degranulation marker CD107a (Figure 2A and B). Overall, these data strongly indicate that neither allergic effector cell expansion or function nor increased IgE-binding capacity appears to drive enhanced anaphylaxis severity in aged mice.Finally, to test the hypothesis whether aging might lead to an increased sensitivity to allergic mediators, we bypassed allergic effector cell activation and directly administered a fixed amount of exogenous histamine to young and aged WT mice (Figure 2C). Strikingly, aged mice showed significantly stronger anaphylactic responses (Figure 2D and E) at equal serum histamine levels (Figure 2F) indicating increased physiological sensitivity to allergic effector cell-derived mediators.In summary, our findings reveal that age-related increase in anaphylaxis severity is independent of altered effector cell activity or mediator release but is associated with an enhanced physiological responsiveness to allergic mediators such as histamine.

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11pt, fleqn, a4paper, ]LegrandOrangeBook Background Autosomal Dominant-Hyper-IgE Syndrome (AD-HIES) is caused by dominant-negative (DN) STAT3 mutations and characterized by high IgE levels, a lack of Th17-cells and recurrent infections with extracellular pathogens. We previously identified an enigmatic population of IL-10 producing CCR6 +B-helper T-cells and investigated here their relationship to Th17-cells and STAT3 signalling requirements. Methods Human blood lymphocytes were analysed by multiparametric flow cytometry in healthy donors and AD-HIES patients. Analysis was performed by conventional gating or with bioinformatic tools. FACS-purified T-cell subsets were activated in vitro and Th17 differentiation assessed. T-cell antigen specificities were assessed by activation with heat-killed pathogens or antigenic peptide pools. B helper capacities were determined according to antibody secretion in B-T co-cultures by ELISA. Results CCR6 +Th-cells that lacked subset-defining differentiation markers were mostly non-polarised central memory T-cells (T CM) that produced IL-10 and expressed RORγt. They were pre-committed to a Th17 fate, since TCR stimulation in the absence of polarising cytokines induced efficient Th17 differentiation. The latter was promoted by an autocrine loop of STAT3-activating cytokines. CCR6 +Th-cells were reduced in patients with DN-STAT3 mutations but contained activated CCR6 +T CM that produced IL-10 and responded vigorously to AD-HIES-associated pathogens. These residual CCR6 +Th-cells provided B-cell help for IgG and IgE production. Conclusions Th17 differentiation in AD-HIES patients was not completely impaired but arrested at an intermediate stage of IL-10 producing “pre-Th17”-cells. Surprisingly, DN-STAT3 mutations did not inhibit IL-10 production by CD4 +T-cells. Pre-Th17-cells were activated by AD-HIES-associated pathogens and possessed B-helper functions, suggesting that they are not protective but promote aberrant IgE production.

5y follow up study of single dose challenges in the diagnosis and management of cow’s milk allergy in infants

Background: Allergic rhinitis (AR) is an IgE-mediated inflammatory condition characterized by Th2-skewed immune responses to allergens. Immune alterations in memory T cells, T follicular helper (Tfh) cells, and regulatory T (Treg) cells may influence baseline immune activity in AR patients even in the absence of allergen exposure, promoting sustained cytokine dysregulation, aberrant Tfh-B cell interactions, and impaired immune regulation. Aim: This study aimed to investigate the role and function of T cell subsets in AR by analyzing PBMCs from AR patients and healthy controls, focusing on immunological differences and their implications. Methods: Peripheral blood mononuclear cells from AR patients and healthy individuals were analyzed via flow cytometry to assess Th1, Th2, Th17, Tregs, and Tfh cells. Results: Off-season shifts in T cell populations were observed in AR patients compared to healthy controls. Memory T-helper (Th) cells in AR patients showed reduced frequencies of Th1/Th17 subsets and CD49d -CD27 + memory Th cells, indicating a skewed T cell profile. T follicular helper (Tfh) cells also displayed an altered distribution: AR patients had decreased Tfh1 and Tfh1/Th17 frequencies, but increased Tfh17 and Tfh2 populations, suggesting enhanced Tfh-driven B cell support. Regulatory T (Treg) cells were similarly dysregulated, with reduced frequencies of Th1/Th17-like CD49d -CD27 + Tregs and CD49d -CD27 - Tregs, reflecting impaired immune regulation. Conclusion: Off-season memory Th cell polarization, Tfh subset skewing, and Treg dysfunction in AR likely prime patients for exaggerated immune responses upon pollen exposure. These immunologic alterations provide a mechanistic link to the heightened Th2 cytokine release and IgE-mediated inflammation that trigger AR symptoms during pollen season.

Hypersensitivity reactions to quinolones (QHRs) have been increasing in frequency, thus classifying them as the second most frequently implicated class of antibiotics in HRs. It is noteworthy that quinolones (Qs) have been observed to predominantly trigger immediate hypersensitivity reactions (IHRs). These reactions are categorised as either IgE-mediated or non-IgE-mediated, attributable to the off-target occupation of the recently described receptor, Mas-related G-protein coupled receptor member X2 (MRGPRX2), on effector cells. The increasing trend of HRs underscores the necessity for enhanced diagnostic and management strategies. The present position paper aims to shed light on the key mechanisms involved in immediate and non-immediate QHRs. The clinical spectrum of these reactions is discussed, as well as the utility of skin tests, in vitro diagnostic tests and drug provocation tests in diagnosis. A further focal point of this study is the analysis of cross-reactivity between various quinolones. The paper concludes with the presentation of diagnostic algorithms for both immediate and non-immediate QHRs. The paper’s findings aid clinical practice for QHRs and address unmet needs, which should stimulate more in-depth investigations into the mechanisms and clinical practice of QHRs.

Introduction:Per- and Polyfluoroalkyl Substances (PFAS) are widely used chemicals, notably in nonstick coatings, fire-fighting foams and equipment, and surfactants. These chemicals degrade slowly and accumulate in tissues and the environment, being detected in water, air, wildlife, and soil across the world. Initial studies have shown that these chemicals are associated with harmful health effects, but research in this area remains limited, especially in sinonasal diseases. Methods:The National Health and Nutrition Examination Survey (NHANES) 2011-2014 was used to analyze the association between PFAS and taste and smell survey among adults (age≥40) with complete data (n=1911). The survey included self-reported sinonasal symptoms. Multivariable logistic regression adjusted for covariates was used to describe the relationship between serum PFAS concentrations and sinonasal health. Bayesian kernel machine regression (BKMR) was performed to consider the diverse chemical properties of PFAS and how real-life exposures involve multiple types of PFAS. Results:The logistic regression model found that serum PFAS levels were not significantly associated with sinonasal health outcomes, except serum Me-PFOSA-AcOH (OR: 1.164; 95% CI: 1.020, 1.308), which significantly increased the likelihood of reporting frequent nasal congestion in the past 12 months. The BKMR model identified exposure-response relationships on olfaction of Me-FPOSA-AcOH and PFHxS becoming more pronounced as the concentration of PFNA within the mixture increased. Conclusion:Our results highlight a potential relationship between PFAS and adverse sinonasal health effects. Exposure to Me-PFOSA-AcOH may be related to frequent nasal congestion while other PFAS may have complex, mixture-dependent effects on olfaction.