Kari Nadeau | Stanford University (original) (raw)

Papers by Kari Nadeau

Research paper thumbnail of Changes in peanut-specific T-cell clonotype with oral immunotherapy

Journal of Allergy and Clinical Immunology, 2015

Research paper thumbnail of Single B-cell deconvolution of peanut-specific antibody responses in allergic patients

Journal of Allergy and Clinical Immunology, 2015

The frequencies, cellular phenotypes, epitope specificity, and clonal diversity of allergen-speci... more The frequencies, cellular phenotypes, epitope specificity, and clonal diversity of allergen-specific B cells in patients with food allergy are not fully understood but are of major pathogenic and therapeutic significance. We sought to characterize peanut allergen-specific B-cell populations and the sequences and binding activities of their antibodies before and during immunotherapy. B cells binding fluorescently labeled Ara h 1 or Ara h 2 were phenotyped and isolated by means of flow cytometric sorting from 18 patients at baseline and 13 patients during therapy. Fifty-seven mAbs derived from allergen-binding single B cells were evaluated by using ELISA, Western blotting, and peptide epitope mapping. Deep sequencing of the B-cell repertoires identified additional members of the allergen-specific B-cell clones. Median allergen-binding B-cell frequencies were 0.0097% (Ara h 1) or 0.029% (Ara h 2) of B cells in baseline blood from allergic patients and approximately 3-fold higher during immunotherapy. Five of 57 allergen-specific cells belonged to clones containing IgE-expressing members. Almost all allergen-specific antibodies were mutated, and binding to both conformational and linear allergen epitopes was detected. Increasing somatic mutation of IgG4 members of a clone was seen in immunotherapy, whereas IgE mutation levels in the clone did not increase. Most peanut allergen-binding B cells isolated by means of antigen-specific flow sorting express mutated and isotype-switched antibodies. Immunotherapy increases their frequency in the blood, and even narrowly defined allergen epitopes are recognized by numerous distinct B-cell clones in a patient. The results also suggest that oral immunotherapy can stimulate somatic mutation of allergen-specific IgG4.

Research paper thumbnail of PRKDC mutations associated with immunodeficiency, granuloma, and autoimmune regulator-dependent autoimmunity

The Journal of allergy and clinical immunology, 2015

PRKDC encodes for DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a kinase that forms ... more PRKDC encodes for DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a kinase that forms part of a complex (DNA-dependent protein kinase [DNA-PK]) crucial for DNA double-strand break repair and V(D)J recombination. In mice DNA-PK also interacts with the transcription factor autoimmune regulator (AIRE) to promote central T-cell tolerance. We sought to understand the causes of an inflammatory disease with granuloma and autoimmunity associated with decreasing T- and B-cell counts over time that had been diagnosed in 2 unrelated patients. Genetic, molecular, and functional analyses were performed to characterize an inflammatory disease evocative of a combined immunodeficiency. We identified PRKDC mutations in both patients. These patients exhibited a defect in DNA double-strand break repair and V(D)J recombination. Whole-blood mRNA analysis revealed a strong interferon signature. On activation, memory T cells displayed a skewed cytokine response typical of TH2 and TH1 but not TH...

Research paper thumbnail of Two year effects of food allergen immunotherapy on quality of life in caregivers of children with food allergies

Allergy, asthma, and clinical immunology : official journal of the Canadian Society of Allergy and Clinical Immunology, 2014

Food allergy (FA) can have serious psychosocial and economic repercussions on food-allergic child... more Food allergy (FA) can have serious psychosocial and economic repercussions on food-allergic children and their caregivers and be associated with negative effects on their quality of life. Food allergen immunotherapy (IT) is a promising experimental therapy but can be linked to anxiety. This study investigated the effects of IT on FA-specific health-related quality of life (HRQL) over a 24 month-follow-up in caregivers of children with single and multiple food allergies. We hypothesized that characteristics such as age, asthma at baseline and respiratory allergic reactions during therapy were key characteristics that influenced HRQL scores. A validated Food Allergy Quality of Life - Parental Burden Questionnaire (FAQL-PB) was used to assess HRQL. It was randomly distributed to and filled out by caregivers of 57 food-allergic children enrolled in clinical trials of IT. The same parent answered the FABQL-PB questionnaire at baseline and for 6-month, 12- month, 18- month, and 24-month t...

Research paper thumbnail of Epigenetic regulation of asthma and allergic disease

Allergy, asthma, and clinical immunology : official journal of the Canadian Society of Allergy and Clinical Immunology, 2014

Epigenetics of asthma and allergic disease is a field that has expanded greatly in the last decad... more Epigenetics of asthma and allergic disease is a field that has expanded greatly in the last decade. Previously thought only in terms of cell differentiation, it is now evident the epigenetics regulate many processes. With T cell activation, commitment toward an allergic phenotype is tightly regulated by DNA methylation and histone modifications at the Th2 locus control region. When normal epigenetic control is disturbed, either experimentally or by environmental exposures, Th1/Th2 balance can be affected. Epigenetic marks are not only transferred to daughter cells with cell replication but they can also be inherited through generations. In animal models, with constant environmental pressure, epigenetically determined phenotypes are amplified through generations and can last up to 2 generations after the environment is back to normal. In this review on the epigenetic regulation of asthma and allergic diseases we review basic epigenetic mechanisms and discuss the epigenetic control of...

Research paper thumbnail of Lessons learned from mice and man: Mimicking human allergy through mouse models

Clinical Immunology, 2014

The relevance of using mouse models to represent human allergic pathologies is still unclear. Rec... more The relevance of using mouse models to represent human allergic pathologies is still unclear. Recent studies suggest the limitations of using models as a standard for assessing immune response and tolerance mechanisms, as mouse models often do not sufficiently depict human atopic conditions. Allergy is a combination of aberrant responses to innocuous environmental agents and the subsequent T H 2-mediated inflammatory responses. In this review, we will discuss current paradigms of allergyspecifically, T H 2-mediated and IgE-associated immune responsesand current mouse models used to recreate these T H 2-mediated pathologies. Our overall goal is to highlight discrepancies that exist between mice and men by examining the advantages and disadvantages of allergic mouse models with respect to the human allergic condition.

Research paper thumbnail of Epigenetic modifications and improved regulatory T-cell function in subjects undergoing dual sublingual immunotherapy

Allergen-specific immunotherapy is the only mode of therapy that has been demonstrated to offer a... more Allergen-specific immunotherapy is the only mode of therapy that has been demonstrated to offer a cure in patients with IgE-mediated respiratory allergies. We sought to demonstrate the safety and efficacy of timothy grass (TG) and dust mite (DM) dual sublingual immunotherapy (SLIT) and to begin to investigate the immune mechanisms involved in successful immunotherapy with multiple allergens. The safety and efficacy of dual SLIT with TG and DM in children and adults with demonstrated allergies to TG and DM were investigated in a single-center, randomized, double-blind, controlled phase I study. Thirty subjects received either TG and DM dual SLIT (n= 20) or placebo (n = 10). Immune parameters were evaluated for differentiation of desensitized subjects from control subjects. Subjects treated with dual SLIT had decreased rhinoconjunctivitis scores (P < .001) and medication use scores (P < .001) and reduced responses to TG and DM allergen based on results of skin prick tests or nasal disk challenges (P < .01 and P < .001, respectively) compared with placebo-treated control subjects. An increase in TG- and DM-specific IgG(4) levels, reduced allergen-specific IgE levels, and subsequent basophil activation were observed in the active treatment group. Dual SLIT promoted allergen-specific suppressive CD4(+)CD25(high)CD127(low)CD45RO(+) forkhead box protein 3 (Foxp3)(+) memory regulatory T cells with reduced DNA methylation of CpG sites within the Foxp3 locus. The results of this pilot study suggest that dual SLIT could be an effective means to treat subjects with sensitivities to a variety of allergens and that long-term tolerance might be induced by epigenetic modifications of Foxp3 in memory regulatory T cells.

Research paper thumbnail of TSLP directly impairs pulmonary Treg function: association with aberrant tolerogenic immunity in asthmatic airway

Background: Even though thymic stromal lymphopoietin (TSLP) has been implicated in the developmen... more Background: Even though thymic stromal lymphopoietin (TSLP) has been implicated in the development of allergic inflammation, its influence on immune tolerance mediated by regulatory T cells (Treg) have not been explored. We aimed to dissect the influence of TSLP on immunosuppressive activities of Treg and its potential consequences in human allergic asthma. Methods: In vitro culture system was utilized to study the effects of TSLP on human Treg. The functional competency of pulmonary Treg from a cohort of 15 allergic asthmatic, 15 healthy control, and 15 non-allergic asthmatic subjects was also evaluated by suppression assays and flow cytometric analysis.

Research paper thumbnail of Eotaxin and FGF enhance signaling through an Extracellular signal-related kinase (ERK)-dependent pathway in the pathogenesis of Eosinophilic Esophagitis

Background: Eosinophilic esophagitis (EoE) is characterized by the inflammation of the esophagus ... more Background: Eosinophilic esophagitis (EoE) is characterized by the inflammation of the esophagus and the infiltration of eosinophils into the esophagus, leading to symptoms such as dysphagia and stricture formation. Systemic immune indicators like eotaxin and fibroblast growth factor were evaluated for possible synergistic pathological effects. Moreover, blood cells, local tissue, and plasma from EoE and control subjects were studied to determine if the localized disease was associated with a systemic effect that correlated with presence of EoE disease. Method: Real-time polymerase chain reaction from peripheral blood mononuclear cells (PBMC), immunohistochemistry from local esophageal biopsies, fluid assays on plasma, and fluorescence-activated cell sorting on peripheral blood cells from subjects were used to study the systemic immune indicators in newly diagnosed EoE (n = 35), treated EoE (n = 9), Gastroesophageal reflux disease (GERD) (n = 8), ulcerative colitis (n = 5), Crohn's disease (n = 5), and healthy controls (n = 8).

Research paper thumbnail of Long-term Sinonasal Outcomes of Aspirin Desensitization in Aspirin Exacerbated Respiratory Disease

Otolaryngology -- Head and Neck Surgery, 2014

Objective. This study aimed to assess sinonasal outcomes in patients with aspirin exacerbated res... more Objective. This study aimed to assess sinonasal outcomes in patients with aspirin exacerbated respiratory disease (AERD) undergoing aspirin desensitization following endoscopic sinus surgery (ESS).

Research paper thumbnail of GWAS identifies four novel eosinophilic esophagitis loci

Nature communications, 2014

Eosinophilic esophagitis (EoE) is an allergic disorder characterized by infiltration of the oesop... more Eosinophilic esophagitis (EoE) is an allergic disorder characterized by infiltration of the oesophagus with eosinophils. We had previously reported association of the TSLP/WDR36 locus with EoE. Here we report genome-wide significant associations at four additional loci; c11orf30 and STAT6, which have been previously associated with both atopic and autoimmune diseases, and two EoE-specific loci, ANKRD27 that regulates the trafficking of melanogenic enzymes to epidermal melanocytes and CAPN14, that encodes a calpain whose expression is highly enriched in the oesophagus. The identification of five EoE loci, not only expands our aetiological understanding of the disease but may also represent new therapeutic targets to treat the most debilitating aspect of EoE, oesophageal inflammation and remodelling.

Research paper thumbnail of Identification of STAT5A and STAT5B target genes in human T cells

PloS one, 2014

Signal transducer and activator of transcription (STAT) comprises a family of universal transcrip... more Signal transducer and activator of transcription (STAT) comprises a family of universal transcription factors that help cells sense and respond to environmental signals. STAT5 refers to two highly related proteins, STAT5A and STAT5B, with critical function: their complete deficiency is lethal in mice; in humans, STAT5B deficiency alone leads to endocrine and immunological problems, while STAT5A deficiency has not been reported. STAT5A and STAT5B show peptide sequence similarities greater than 90%, but subtle structural differences suggest possible non-redundant roles in gene regulation. However, these roles remain unclear in humans. We applied chromatin immunoprecipitation followed by DNA sequencing using human CD4(+) T cells to detect candidate genes regulated by STAT5A and/or STAT5B, and quantitative-PCR in STAT5A or STAT5B knock-down (KD) human CD4(+) T cells to validate the findings. Our data show STAT5A and STAT5B play redundant roles in cell proliferation and apoptosis via SGK...

Research paper thumbnail of Ambient polycyclic aromatic hydrocarbons and pulmonary function in children

Journal of Exposure Science and Environmental Epidemiology, 2014

Few studies have examined the relationship between ambient polycyclic aromatic hydrocarbons (PAHs... more Few studies have examined the relationship between ambient polycyclic aromatic hydrocarbons (PAHs) and pulmonary function in children. Major sources include vehicular emissions, home heating, wildland fires, agricultural burning, and power plants. PAHs are an important component of fine particulate matter that has been linked to respiratory health. This cross-sectional study examines the relationship between estimated individual exposures to the sum of PAHs with 4, 5, or 6 rings (PAH456) and pulmonary function tests (forced expiratory volume in one second (FEV 1 ) and forced expiratory flow between 25% and 75% of vital capacity) in asthmatic and non-asthmatic children. We applied land-use regression to estimate individual exposures to ambient PAHs for averaging periods ranging from 1 week to 1 year. We used linear regression to estimate the relationship between exposure to PAH456 with pre-and postbronchodilator pulmonary function tests in children in Fresno, California (N ¼ 297). Among nonasthmatics, there was a statistically significant association between PAH456 during the previous 3 months, 6 months, and 1 year and postbronchodilator FEV 1 . The magnitude of the association increased with the length of the averaging period ranging from 60 to 110 ml decrease in FEV 1 for each 1 ng/m 3 increase in PAH456. There were no associations with PAH456 observed among asthmatic children. We identified an association between annual PAHs and chronic pulmonary function in children without asthma. Additional studies are needed to further explore the association between exposure to PAHs and pulmonary function, especially with regard to differential effects between asthmatic and non-asthmatic children.

Research paper thumbnail of Genome-wide association study identifies peanut allergy-specific loci and evidence of epigenetic mediation in US children

Nature communications, 2015

Food allergy (FA) affects 2%-10% of US children and is a growing clinical and public health probl... more Food allergy (FA) affects 2%-10% of US children and is a growing clinical and public health problem. Here we conduct the first genome-wide association study of well-defined FA, including specific subtypes (peanut, milk and egg) in 2,759 US participants (1,315 children and 1,444 parents) from the Chicago Food Allergy Study, and identify peanut allergy (PA)-specific loci in the HLA-DR and -DQ gene region at 6p21.32, tagged by rs7192 (P=5.5 × 10(-8)) and rs9275596 (P=6.8 × 10(-10)), in 2,197 participants of European ancestry. We replicate these associations in an independent sample of European ancestry. These associations are further supported by meta-analyses across the discovery and replication samples. Both single-nucleotide polymorphisms (SNPs) are associated with differential DNA methylation levels at multiple CpG sites…

Research paper thumbnail of Multiple-allergen oral immunotherapy improves quality of life in caregivers of food-allergic pediatric subjects

Allergy, Asthma & Clinical Immunology, 2014

Background: Food allergy (FA) negatively affects quality of life in caregivers of food-allergic c... more Background: Food allergy (FA) negatively affects quality of life in caregivers of food-allergic children, imposing a psychosocial and economic burden. Oral immunotherapy (OIT) is a promising investigational therapy for FA. However, OIT can be a source of anxiety as it carries risk for allergic reactions. The effect of OIT with multiple food allergens (mOIT) on FA-specific health-related quality of life (HRQL) has never been studied in participants with multiple, severe food allergies. This study is the first to investigate the effects of mOIT on FA-related HRQL in caregivers of pediatric subjects. Methods: Caregiver HRQL was assessed using a validated Food Allergy Quality of Life -Parental Burden (FAQL-PB) Questionnaire (J Allergy Clin Immunol 114 : [1159][1160][1161][1162][1163] 2004). Parents of participants in two single-center Phase I clinical trials receiving mOIT (n = 29) or rush mOIT with anti-IgE (omalizumab) pre-treatment (n = 11) completed the FAQL-PB prior to study intervention and at 2 follow-up time-points (6 months and 18 months). Parents of subjects not receiving OIT (control group, n = 10) completed the FAQL-PB for the same time-points. Results: HRQL improved with clinical (change < −0.5) and statistical (p < 0.05) significance in the mOIT group (baseline mean 3.9, 95% CI 3.4-4.4; 6-month follow-up mean 2.5, 95% CI 2.0-3.0; 18-month follow-up mean 1.8, 95% CI 1.4-2.1) and rush mOIT group (baseline mean 3.9, 95% CI 3.1-4.7; 6-month follow-up mean 1.7, 95% CI 0.9-2.6; 18-month follow-up mean 1.3, 95% CI 0.3-2.4). HRQL scores did not significantly change in the control group (n = 10).

Research paper thumbnail of Twin and family studies reveal strong environmental and weaker genetic cues explaining heritability of eosinophilic esophagitis

Background: Eosinophilic esophagitis (EoE) is a chronic antigen-driven allergic inflammatory dise... more Background: Eosinophilic esophagitis (EoE) is a chronic antigen-driven allergic inflammatory disease, likely involving the interplay of genetic and environmental factors, yet their respective contributions to heritability are unknown. Objective: To quantify the risk associated with genes and environment on familial clustering of EoE. Methods: Family history was obtained from a hospital-based cohort of 914 EoE probands (n 5 2192 first-degree ''Nuclear-Family'' relatives) and an international registry of monozygotic and dizygotic twins/triplets (n 5 63 EoE ''Twins'' probands). Frequencies, recurrence risk ratios (RRRs), heritability, and twin concordance were estimated. Environmental exposures were preliminarily examined. Results: Analysis of the Nuclear-Family-based cohort revealed that the rate of EoE, in first-degree relatives of a proband, was 1.8% (unadjusted) and 2.3% (sex-adjusted). RRRs ranged from 10 to 64, depending on the family relationship, and were higher in brothers (64.0; P 5 .04), fathers (42.9; P 5 .004), and males (50.7; P < .001) than in sisters, mothers, and females, respectively. The risk of EoE for other siblings was 2.4%. In the Nuclear-Family cohort, combined gene and common environment heritability was 72.0% 6 2.7% (P < .001). In the From a the

Research paper thumbnail of Intravenous anti–IL-13 mAb QAX576 for the treatment of eosinophilic esophagitis

Journal of Allergy and Clinical Immunology, 2014

Eosinophilic esophagitis (EoE) is a chronic allergic disease with limited treatment options. We e... more Eosinophilic esophagitis (EoE) is a chronic allergic disease with limited treatment options. We evaluated QAX576, an mAb against IL-13, in the treatment of patients with EoE. Patients (18-50 years) with proton pump inhibitor-resistant esophageal eosinophilia received intravenous QAX576 (6 mg/kg) or placebo (2:1) at weeks 0, 4, and 8 and were followed for 6 months. The primary end point was the responder rate for a greater than 75% decrease in peak eosinophil counts at week 12. Efficacy was to be declared if the lower 90% confidence limit for the proportion of responders on QAX576 was 35% or greater. Secondary end points included changes in esophageal eosinophil counts, symptoms assessed by questionnaire scores, and quantification of a series of biomarkers. Twenty-three patients completed the study up to week 12, and 18 continued to the end of the study. For the proximal and distal esophageal biopsies combined, the responder rate was 12.5% (90% confidence limit, 1% to 43%) with placebo, compared to 40.0% (90% confidence limit, 22% to 61%) with QAX576. Although the primary end point was not met, the mean esophageal eosinophil count decreased by 60% with QAX576 versus an increase of 23% with placebo (P = .004), and the decrease was sustained up to 6 months. There was a trend for improved symptoms, particularly dysphagia. QAX576 improved expression of EoE-relevant esophageal transcripts, including eotaxin-3, periostin, and markers of mast cells and barrier function, for up to 6 months after treatment. QAX576 was well tolerated. QAX576 significantly improved intraepithelial esophageal eosinophil counts and dysregulated esophageal disease-related transcripts in adults with EoE in a sustained manner.

Research paper thumbnail of Single blood drop diagnostic activation test (DAT) for food allergies

Clinical and Translational Allergy, 2011

Background Quantitative measurement of basophil cell surface markers, CD63 and CD203c, by flow cy... more Background Quantitative measurement of basophil cell surface markers, CD63 and CD203c, by flow cytometry has been developed as useful tool for the diagnosis of IgE mediated allergies. Available methods require large volume of blood and include extra steps such ...

Research paper thumbnail of Autoimmune regulator (AIRE) contributes to Dectin-1–induced TNF-α production and complexes with caspase recruitment domain–containing protein 9 (CARD9), spleen tyrosine kinase (Syk), and Dectin-1

Journal of Allergy and Clinical Immunology, 2012

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome is a complex imm... more Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome is a complex immunologic disease caused by mutation of the autoimmune regulator (AIRE) gene. Autoimmunity in patients with APECED syndrome has been shown to result from deficiency of AIRE function in transcriptional regulation of thymic peripheral tissue antigens, which leads to defective T-cell negative selection. Candidal susceptibility in patients with APECED syndrome is thought to result from aberrant adaptive immunity. To determine whether AIRE could function in anticandidal innate immune signaling, we investigated an extrathymic role for AIRE in the immune recognition of β-glucan through the Dectin-1 pathway, which is required for defense against Candida species. Innate immune signaling through the Dectin-1 pathway was assessed in both PBMCs from patients with APECED syndrome and a monocytic cell line. Subcellular localization of AIRE was assessed by using confocal microscopy. PBMCs from patients with APECED syndrome had reduced TNF-α responses after Dectin-1 ligation but in part used a Raf-1-mediated pathway to preserve function. In the THP-1 human monocytic cell line, reducing AIRE expression resulted in significantly decreased TNF-α release after Dectin-1 ligation. AIRE formed a transient complex with the known Dectin-1 pathway components phosphorylated spleen tyrosine kinase and caspase recruitment domain-containing protein 9 after receptor ligation and localized with Dectin-1 at the cell membrane. AIRE can participate in the Dectin-1 signaling pathway, indicating a novel extrathymic role for AIRE and a defect that likely contributes to fungal susceptibility in patients with APECED syndrome.

Research paper thumbnail of Ambient air pollution impairs regulatory T-cell function in asthma

Journal of Allergy and Clinical Immunology, 2010

Research paper thumbnail of Changes in peanut-specific T-cell clonotype with oral immunotherapy

Journal of Allergy and Clinical Immunology, 2015

Research paper thumbnail of Single B-cell deconvolution of peanut-specific antibody responses in allergic patients

Journal of Allergy and Clinical Immunology, 2015

The frequencies, cellular phenotypes, epitope specificity, and clonal diversity of allergen-speci... more The frequencies, cellular phenotypes, epitope specificity, and clonal diversity of allergen-specific B cells in patients with food allergy are not fully understood but are of major pathogenic and therapeutic significance. We sought to characterize peanut allergen-specific B-cell populations and the sequences and binding activities of their antibodies before and during immunotherapy. B cells binding fluorescently labeled Ara h 1 or Ara h 2 were phenotyped and isolated by means of flow cytometric sorting from 18 patients at baseline and 13 patients during therapy. Fifty-seven mAbs derived from allergen-binding single B cells were evaluated by using ELISA, Western blotting, and peptide epitope mapping. Deep sequencing of the B-cell repertoires identified additional members of the allergen-specific B-cell clones. Median allergen-binding B-cell frequencies were 0.0097% (Ara h 1) or 0.029% (Ara h 2) of B cells in baseline blood from allergic patients and approximately 3-fold higher during immunotherapy. Five of 57 allergen-specific cells belonged to clones containing IgE-expressing members. Almost all allergen-specific antibodies were mutated, and binding to both conformational and linear allergen epitopes was detected. Increasing somatic mutation of IgG4 members of a clone was seen in immunotherapy, whereas IgE mutation levels in the clone did not increase. Most peanut allergen-binding B cells isolated by means of antigen-specific flow sorting express mutated and isotype-switched antibodies. Immunotherapy increases their frequency in the blood, and even narrowly defined allergen epitopes are recognized by numerous distinct B-cell clones in a patient. The results also suggest that oral immunotherapy can stimulate somatic mutation of allergen-specific IgG4.

Research paper thumbnail of PRKDC mutations associated with immunodeficiency, granuloma, and autoimmune regulator-dependent autoimmunity

The Journal of allergy and clinical immunology, 2015

PRKDC encodes for DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a kinase that forms ... more PRKDC encodes for DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a kinase that forms part of a complex (DNA-dependent protein kinase [DNA-PK]) crucial for DNA double-strand break repair and V(D)J recombination. In mice DNA-PK also interacts with the transcription factor autoimmune regulator (AIRE) to promote central T-cell tolerance. We sought to understand the causes of an inflammatory disease with granuloma and autoimmunity associated with decreasing T- and B-cell counts over time that had been diagnosed in 2 unrelated patients. Genetic, molecular, and functional analyses were performed to characterize an inflammatory disease evocative of a combined immunodeficiency. We identified PRKDC mutations in both patients. These patients exhibited a defect in DNA double-strand break repair and V(D)J recombination. Whole-blood mRNA analysis revealed a strong interferon signature. On activation, memory T cells displayed a skewed cytokine response typical of TH2 and TH1 but not TH...

Research paper thumbnail of Two year effects of food allergen immunotherapy on quality of life in caregivers of children with food allergies

Allergy, asthma, and clinical immunology : official journal of the Canadian Society of Allergy and Clinical Immunology, 2014

Food allergy (FA) can have serious psychosocial and economic repercussions on food-allergic child... more Food allergy (FA) can have serious psychosocial and economic repercussions on food-allergic children and their caregivers and be associated with negative effects on their quality of life. Food allergen immunotherapy (IT) is a promising experimental therapy but can be linked to anxiety. This study investigated the effects of IT on FA-specific health-related quality of life (HRQL) over a 24 month-follow-up in caregivers of children with single and multiple food allergies. We hypothesized that characteristics such as age, asthma at baseline and respiratory allergic reactions during therapy were key characteristics that influenced HRQL scores. A validated Food Allergy Quality of Life - Parental Burden Questionnaire (FAQL-PB) was used to assess HRQL. It was randomly distributed to and filled out by caregivers of 57 food-allergic children enrolled in clinical trials of IT. The same parent answered the FABQL-PB questionnaire at baseline and for 6-month, 12- month, 18- month, and 24-month t...

Research paper thumbnail of Epigenetic regulation of asthma and allergic disease

Allergy, asthma, and clinical immunology : official journal of the Canadian Society of Allergy and Clinical Immunology, 2014

Epigenetics of asthma and allergic disease is a field that has expanded greatly in the last decad... more Epigenetics of asthma and allergic disease is a field that has expanded greatly in the last decade. Previously thought only in terms of cell differentiation, it is now evident the epigenetics regulate many processes. With T cell activation, commitment toward an allergic phenotype is tightly regulated by DNA methylation and histone modifications at the Th2 locus control region. When normal epigenetic control is disturbed, either experimentally or by environmental exposures, Th1/Th2 balance can be affected. Epigenetic marks are not only transferred to daughter cells with cell replication but they can also be inherited through generations. In animal models, with constant environmental pressure, epigenetically determined phenotypes are amplified through generations and can last up to 2 generations after the environment is back to normal. In this review on the epigenetic regulation of asthma and allergic diseases we review basic epigenetic mechanisms and discuss the epigenetic control of...

Research paper thumbnail of Lessons learned from mice and man: Mimicking human allergy through mouse models

Clinical Immunology, 2014

The relevance of using mouse models to represent human allergic pathologies is still unclear. Rec... more The relevance of using mouse models to represent human allergic pathologies is still unclear. Recent studies suggest the limitations of using models as a standard for assessing immune response and tolerance mechanisms, as mouse models often do not sufficiently depict human atopic conditions. Allergy is a combination of aberrant responses to innocuous environmental agents and the subsequent T H 2-mediated inflammatory responses. In this review, we will discuss current paradigms of allergyspecifically, T H 2-mediated and IgE-associated immune responsesand current mouse models used to recreate these T H 2-mediated pathologies. Our overall goal is to highlight discrepancies that exist between mice and men by examining the advantages and disadvantages of allergic mouse models with respect to the human allergic condition.

Research paper thumbnail of Epigenetic modifications and improved regulatory T-cell function in subjects undergoing dual sublingual immunotherapy

Allergen-specific immunotherapy is the only mode of therapy that has been demonstrated to offer a... more Allergen-specific immunotherapy is the only mode of therapy that has been demonstrated to offer a cure in patients with IgE-mediated respiratory allergies. We sought to demonstrate the safety and efficacy of timothy grass (TG) and dust mite (DM) dual sublingual immunotherapy (SLIT) and to begin to investigate the immune mechanisms involved in successful immunotherapy with multiple allergens. The safety and efficacy of dual SLIT with TG and DM in children and adults with demonstrated allergies to TG and DM were investigated in a single-center, randomized, double-blind, controlled phase I study. Thirty subjects received either TG and DM dual SLIT (n= 20) or placebo (n = 10). Immune parameters were evaluated for differentiation of desensitized subjects from control subjects. Subjects treated with dual SLIT had decreased rhinoconjunctivitis scores (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001) and medication use scores (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001) and reduced responses to TG and DM allergen based on results of skin prick tests or nasal disk challenges (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01 and P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001, respectively) compared with placebo-treated control subjects. An increase in TG- and DM-specific IgG(4) levels, reduced allergen-specific IgE levels, and subsequent basophil activation were observed in the active treatment group. Dual SLIT promoted allergen-specific suppressive CD4(+)CD25(high)CD127(low)CD45RO(+) forkhead box protein 3 (Foxp3)(+) memory regulatory T cells with reduced DNA methylation of CpG sites within the Foxp3 locus. The results of this pilot study suggest that dual SLIT could be an effective means to treat subjects with sensitivities to a variety of allergens and that long-term tolerance might be induced by epigenetic modifications of Foxp3 in memory regulatory T cells.

Research paper thumbnail of TSLP directly impairs pulmonary Treg function: association with aberrant tolerogenic immunity in asthmatic airway

Background: Even though thymic stromal lymphopoietin (TSLP) has been implicated in the developmen... more Background: Even though thymic stromal lymphopoietin (TSLP) has been implicated in the development of allergic inflammation, its influence on immune tolerance mediated by regulatory T cells (Treg) have not been explored. We aimed to dissect the influence of TSLP on immunosuppressive activities of Treg and its potential consequences in human allergic asthma. Methods: In vitro culture system was utilized to study the effects of TSLP on human Treg. The functional competency of pulmonary Treg from a cohort of 15 allergic asthmatic, 15 healthy control, and 15 non-allergic asthmatic subjects was also evaluated by suppression assays and flow cytometric analysis.

Research paper thumbnail of Eotaxin and FGF enhance signaling through an Extracellular signal-related kinase (ERK)-dependent pathway in the pathogenesis of Eosinophilic Esophagitis

Background: Eosinophilic esophagitis (EoE) is characterized by the inflammation of the esophagus ... more Background: Eosinophilic esophagitis (EoE) is characterized by the inflammation of the esophagus and the infiltration of eosinophils into the esophagus, leading to symptoms such as dysphagia and stricture formation. Systemic immune indicators like eotaxin and fibroblast growth factor were evaluated for possible synergistic pathological effects. Moreover, blood cells, local tissue, and plasma from EoE and control subjects were studied to determine if the localized disease was associated with a systemic effect that correlated with presence of EoE disease. Method: Real-time polymerase chain reaction from peripheral blood mononuclear cells (PBMC), immunohistochemistry from local esophageal biopsies, fluid assays on plasma, and fluorescence-activated cell sorting on peripheral blood cells from subjects were used to study the systemic immune indicators in newly diagnosed EoE (n = 35), treated EoE (n = 9), Gastroesophageal reflux disease (GERD) (n = 8), ulcerative colitis (n = 5), Crohn's disease (n = 5), and healthy controls (n = 8).

Research paper thumbnail of Long-term Sinonasal Outcomes of Aspirin Desensitization in Aspirin Exacerbated Respiratory Disease

Otolaryngology -- Head and Neck Surgery, 2014

Objective. This study aimed to assess sinonasal outcomes in patients with aspirin exacerbated res... more Objective. This study aimed to assess sinonasal outcomes in patients with aspirin exacerbated respiratory disease (AERD) undergoing aspirin desensitization following endoscopic sinus surgery (ESS).

Research paper thumbnail of GWAS identifies four novel eosinophilic esophagitis loci

Nature communications, 2014

Eosinophilic esophagitis (EoE) is an allergic disorder characterized by infiltration of the oesop... more Eosinophilic esophagitis (EoE) is an allergic disorder characterized by infiltration of the oesophagus with eosinophils. We had previously reported association of the TSLP/WDR36 locus with EoE. Here we report genome-wide significant associations at four additional loci; c11orf30 and STAT6, which have been previously associated with both atopic and autoimmune diseases, and two EoE-specific loci, ANKRD27 that regulates the trafficking of melanogenic enzymes to epidermal melanocytes and CAPN14, that encodes a calpain whose expression is highly enriched in the oesophagus. The identification of five EoE loci, not only expands our aetiological understanding of the disease but may also represent new therapeutic targets to treat the most debilitating aspect of EoE, oesophageal inflammation and remodelling.

Research paper thumbnail of Identification of STAT5A and STAT5B target genes in human T cells

PloS one, 2014

Signal transducer and activator of transcription (STAT) comprises a family of universal transcrip... more Signal transducer and activator of transcription (STAT) comprises a family of universal transcription factors that help cells sense and respond to environmental signals. STAT5 refers to two highly related proteins, STAT5A and STAT5B, with critical function: their complete deficiency is lethal in mice; in humans, STAT5B deficiency alone leads to endocrine and immunological problems, while STAT5A deficiency has not been reported. STAT5A and STAT5B show peptide sequence similarities greater than 90%, but subtle structural differences suggest possible non-redundant roles in gene regulation. However, these roles remain unclear in humans. We applied chromatin immunoprecipitation followed by DNA sequencing using human CD4(+) T cells to detect candidate genes regulated by STAT5A and/or STAT5B, and quantitative-PCR in STAT5A or STAT5B knock-down (KD) human CD4(+) T cells to validate the findings. Our data show STAT5A and STAT5B play redundant roles in cell proliferation and apoptosis via SGK...

Research paper thumbnail of Ambient polycyclic aromatic hydrocarbons and pulmonary function in children

Journal of Exposure Science and Environmental Epidemiology, 2014

Few studies have examined the relationship between ambient polycyclic aromatic hydrocarbons (PAHs... more Few studies have examined the relationship between ambient polycyclic aromatic hydrocarbons (PAHs) and pulmonary function in children. Major sources include vehicular emissions, home heating, wildland fires, agricultural burning, and power plants. PAHs are an important component of fine particulate matter that has been linked to respiratory health. This cross-sectional study examines the relationship between estimated individual exposures to the sum of PAHs with 4, 5, or 6 rings (PAH456) and pulmonary function tests (forced expiratory volume in one second (FEV 1 ) and forced expiratory flow between 25% and 75% of vital capacity) in asthmatic and non-asthmatic children. We applied land-use regression to estimate individual exposures to ambient PAHs for averaging periods ranging from 1 week to 1 year. We used linear regression to estimate the relationship between exposure to PAH456 with pre-and postbronchodilator pulmonary function tests in children in Fresno, California (N ¼ 297). Among nonasthmatics, there was a statistically significant association between PAH456 during the previous 3 months, 6 months, and 1 year and postbronchodilator FEV 1 . The magnitude of the association increased with the length of the averaging period ranging from 60 to 110 ml decrease in FEV 1 for each 1 ng/m 3 increase in PAH456. There were no associations with PAH456 observed among asthmatic children. We identified an association between annual PAHs and chronic pulmonary function in children without asthma. Additional studies are needed to further explore the association between exposure to PAHs and pulmonary function, especially with regard to differential effects between asthmatic and non-asthmatic children.

Research paper thumbnail of Genome-wide association study identifies peanut allergy-specific loci and evidence of epigenetic mediation in US children

Nature communications, 2015

Food allergy (FA) affects 2%-10% of US children and is a growing clinical and public health probl... more Food allergy (FA) affects 2%-10% of US children and is a growing clinical and public health problem. Here we conduct the first genome-wide association study of well-defined FA, including specific subtypes (peanut, milk and egg) in 2,759 US participants (1,315 children and 1,444 parents) from the Chicago Food Allergy Study, and identify peanut allergy (PA)-specific loci in the HLA-DR and -DQ gene region at 6p21.32, tagged by rs7192 (P=5.5 × 10(-8)) and rs9275596 (P=6.8 × 10(-10)), in 2,197 participants of European ancestry. We replicate these associations in an independent sample of European ancestry. These associations are further supported by meta-analyses across the discovery and replication samples. Both single-nucleotide polymorphisms (SNPs) are associated with differential DNA methylation levels at multiple CpG sites…

Research paper thumbnail of Multiple-allergen oral immunotherapy improves quality of life in caregivers of food-allergic pediatric subjects

Allergy, Asthma & Clinical Immunology, 2014

Background: Food allergy (FA) negatively affects quality of life in caregivers of food-allergic c... more Background: Food allergy (FA) negatively affects quality of life in caregivers of food-allergic children, imposing a psychosocial and economic burden. Oral immunotherapy (OIT) is a promising investigational therapy for FA. However, OIT can be a source of anxiety as it carries risk for allergic reactions. The effect of OIT with multiple food allergens (mOIT) on FA-specific health-related quality of life (HRQL) has never been studied in participants with multiple, severe food allergies. This study is the first to investigate the effects of mOIT on FA-related HRQL in caregivers of pediatric subjects. Methods: Caregiver HRQL was assessed using a validated Food Allergy Quality of Life -Parental Burden (FAQL-PB) Questionnaire (J Allergy Clin Immunol 114 : [1159][1160][1161][1162][1163] 2004). Parents of participants in two single-center Phase I clinical trials receiving mOIT (n = 29) or rush mOIT with anti-IgE (omalizumab) pre-treatment (n = 11) completed the FAQL-PB prior to study intervention and at 2 follow-up time-points (6 months and 18 months). Parents of subjects not receiving OIT (control group, n = 10) completed the FAQL-PB for the same time-points. Results: HRQL improved with clinical (change < −0.5) and statistical (p < 0.05) significance in the mOIT group (baseline mean 3.9, 95% CI 3.4-4.4; 6-month follow-up mean 2.5, 95% CI 2.0-3.0; 18-month follow-up mean 1.8, 95% CI 1.4-2.1) and rush mOIT group (baseline mean 3.9, 95% CI 3.1-4.7; 6-month follow-up mean 1.7, 95% CI 0.9-2.6; 18-month follow-up mean 1.3, 95% CI 0.3-2.4). HRQL scores did not significantly change in the control group (n = 10).

Research paper thumbnail of Twin and family studies reveal strong environmental and weaker genetic cues explaining heritability of eosinophilic esophagitis

Background: Eosinophilic esophagitis (EoE) is a chronic antigen-driven allergic inflammatory dise... more Background: Eosinophilic esophagitis (EoE) is a chronic antigen-driven allergic inflammatory disease, likely involving the interplay of genetic and environmental factors, yet their respective contributions to heritability are unknown. Objective: To quantify the risk associated with genes and environment on familial clustering of EoE. Methods: Family history was obtained from a hospital-based cohort of 914 EoE probands (n 5 2192 first-degree ''Nuclear-Family'' relatives) and an international registry of monozygotic and dizygotic twins/triplets (n 5 63 EoE ''Twins'' probands). Frequencies, recurrence risk ratios (RRRs), heritability, and twin concordance were estimated. Environmental exposures were preliminarily examined. Results: Analysis of the Nuclear-Family-based cohort revealed that the rate of EoE, in first-degree relatives of a proband, was 1.8% (unadjusted) and 2.3% (sex-adjusted). RRRs ranged from 10 to 64, depending on the family relationship, and were higher in brothers (64.0; P 5 .04), fathers (42.9; P 5 .004), and males (50.7; P < .001) than in sisters, mothers, and females, respectively. The risk of EoE for other siblings was 2.4%. In the Nuclear-Family cohort, combined gene and common environment heritability was 72.0% 6 2.7% (P < .001). In the From a the

Research paper thumbnail of Intravenous anti–IL-13 mAb QAX576 for the treatment of eosinophilic esophagitis

Journal of Allergy and Clinical Immunology, 2014

Eosinophilic esophagitis (EoE) is a chronic allergic disease with limited treatment options. We e... more Eosinophilic esophagitis (EoE) is a chronic allergic disease with limited treatment options. We evaluated QAX576, an mAb against IL-13, in the treatment of patients with EoE. Patients (18-50 years) with proton pump inhibitor-resistant esophageal eosinophilia received intravenous QAX576 (6 mg/kg) or placebo (2:1) at weeks 0, 4, and 8 and were followed for 6 months. The primary end point was the responder rate for a greater than 75% decrease in peak eosinophil counts at week 12. Efficacy was to be declared if the lower 90% confidence limit for the proportion of responders on QAX576 was 35% or greater. Secondary end points included changes in esophageal eosinophil counts, symptoms assessed by questionnaire scores, and quantification of a series of biomarkers. Twenty-three patients completed the study up to week 12, and 18 continued to the end of the study. For the proximal and distal esophageal biopsies combined, the responder rate was 12.5% (90% confidence limit, 1% to 43%) with placebo, compared to 40.0% (90% confidence limit, 22% to 61%) with QAX576. Although the primary end point was not met, the mean esophageal eosinophil count decreased by 60% with QAX576 versus an increase of 23% with placebo (P = .004), and the decrease was sustained up to 6 months. There was a trend for improved symptoms, particularly dysphagia. QAX576 improved expression of EoE-relevant esophageal transcripts, including eotaxin-3, periostin, and markers of mast cells and barrier function, for up to 6 months after treatment. QAX576 was well tolerated. QAX576 significantly improved intraepithelial esophageal eosinophil counts and dysregulated esophageal disease-related transcripts in adults with EoE in a sustained manner.

Research paper thumbnail of Single blood drop diagnostic activation test (DAT) for food allergies

Clinical and Translational Allergy, 2011

Background Quantitative measurement of basophil cell surface markers, CD63 and CD203c, by flow cy... more Background Quantitative measurement of basophil cell surface markers, CD63 and CD203c, by flow cytometry has been developed as useful tool for the diagnosis of IgE mediated allergies. Available methods require large volume of blood and include extra steps such ...

Research paper thumbnail of Autoimmune regulator (AIRE) contributes to Dectin-1–induced TNF-α production and complexes with caspase recruitment domain–containing protein 9 (CARD9), spleen tyrosine kinase (Syk), and Dectin-1

Journal of Allergy and Clinical Immunology, 2012

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome is a complex imm... more Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome is a complex immunologic disease caused by mutation of the autoimmune regulator (AIRE) gene. Autoimmunity in patients with APECED syndrome has been shown to result from deficiency of AIRE function in transcriptional regulation of thymic peripheral tissue antigens, which leads to defective T-cell negative selection. Candidal susceptibility in patients with APECED syndrome is thought to result from aberrant adaptive immunity. To determine whether AIRE could function in anticandidal innate immune signaling, we investigated an extrathymic role for AIRE in the immune recognition of β-glucan through the Dectin-1 pathway, which is required for defense against Candida species. Innate immune signaling through the Dectin-1 pathway was assessed in both PBMCs from patients with APECED syndrome and a monocytic cell line. Subcellular localization of AIRE was assessed by using confocal microscopy. PBMCs from patients with APECED syndrome had reduced TNF-α responses after Dectin-1 ligation but in part used a Raf-1-mediated pathway to preserve function. In the THP-1 human monocytic cell line, reducing AIRE expression resulted in significantly decreased TNF-α release after Dectin-1 ligation. AIRE formed a transient complex with the known Dectin-1 pathway components phosphorylated spleen tyrosine kinase and caspase recruitment domain-containing protein 9 after receptor ligation and localized with Dectin-1 at the cell membrane. AIRE can participate in the Dectin-1 signaling pathway, indicating a novel extrathymic role for AIRE and a defect that likely contributes to fungal susceptibility in patients with APECED syndrome.

Research paper thumbnail of Ambient air pollution impairs regulatory T-cell function in asthma

Journal of Allergy and Clinical Immunology, 2010