German cockroach subcutaneous immunotherapy: Impact on nasal responses and allergen-specific immunity among urban children with asthma
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PROVIDER: PRJNA1054571 | ENA |
REPOSITORIES: ENA
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Project description:Background: Cockroach allergy contributes to morbidity among urban children with asthma. Few trials address the effect of subcutaneous immunotherapy (SCIT) with cockroach allergen among these at-risk children.Objective: To determine if nasal allergen challenge (NAC) responses to cockroach allergen would improve following one year of SCIT.Methods: Urban children with asthma, cockroach-sensitized (skin prick test [SPT] and serum specific IgE) and reactive on NAC, participated in a yearlong randomized double-blind placebo-controlled SCIT trial using German cockroach extract. The primary endpoint was the change in mean total nasal symptoms scores (TNSS) during NAC after 12 months of SCIT. Changes in nasal transcriptomic responses during NAC, SPT wheal size, serum allergen-specific antibody production and T-cell responses to cockroach allergen were assessed.Results: Changes in mean NAC TNSS did not differ between SCIT-assigned (n=28) versus placebo-assigned (n=29) participants (p=0.63). Nasal transcriptomic responses correlated with TNSS, but a treatment effect was not observed. Cockroach sIgE decreased to a similar extent in both groups, while decreased cockroach SPT wheal size was greater among SCIT participants (p=0.04). A 200-fold increase in cockroach sIgG4 was observed among subjects receiving SCIT (p<0.001) but was unchanged in the placebo group. T-cell interleukin-4 responses following cockroach allergen stimulation decreased to a greater extent among SCIT versus placebo (p=0.002), while no effect was observed for interleukin-10 or interferon-gamma.Conclusion: A year of SCIT failed to alter NAC TNSS and nasal transcriptome responses to cockroach allergen challenge despite systemic effects on allergen-specific skin tests, induction of serum sIgG4 production and down-modulation of allergen stimulated T-cell responses.
2024-12-18 | GSE250580 | GEO
Project description:Purpose: Next-generation transcriptome sequencing was done to understand host and eukaryotic microbiome changes in gene expression in association with defined insecticide selection pressures. The specific goal of this research was to understand whole-body physiological responses in German cockroaches and associated microbiota, at the metatranscriptome level, to defined insecticide selection pressures. Methods: We used the insecticide indoxacarb as the selecting insecticide, which is an important bait active ingredient for cockroach control. Six generations of selection with indoxacarb bait produced a strain with substantial (>20x) resistance relative to inbred control lines originating from the same parental stock. Results: Metatranscriptome sequencing revealed 1123 significantly differentially expressed genes in > two of three statistical models (81 upregulated and 1042 downregulated; FDR p<0.001; log2FC of +/- 1). The majority of upreglated genes were from the host cockroach while the majority of downregulated genes were from associated viruses and the eukaryotic microbiome. Conclusions: We show here significant impacts by insecticide selection on not only host stress-respnses like detoxification, but also on clearace of microbial parasites, pathogens, commensals and/or symbionts.
2021-12-07 | GSE188950 | GEO
Project description:Transcriptome responses to defined insecticide selection pressures in the German cockroach
| PRJNA780882 | ENA
Project description:Peripheral blood samples from children enrolled in the URECA cohort were collected at age 2. In short, at each URECA research center, within 16 hours of blood collection, mononuclear cells were separated and incubated (48 hours, 37C, 5% CO2) in the presence of German cockroach extract (10mg/mL; CR), dust mite extract (Dermatophagoides pteronyssinus, 10mg/mL; DM), tetanus toxoid (5mg/mL; TT), or medium alone (NS).
2018-03-27 | GSE96783 | GEO
Project description:BackgroundNasal allergen challenge (NAC) could be a means to assess indication and/or an outcome of allergen-specific therapies, particularly for perennial allergens. NACs are not commonly conducted in children with asthma, and cockroach NACs are not well established. This study's objective was to identify a range of German cockroach extract doses that induce nasal symptoms and to assess the safety of cockroach NAC in children with asthma.MethodsTen adults (18-37 years) followed by 25 children (8-14 years) with well-controlled, persistent asthma and cockroach sensitization underwent NAC with diluent followed by up to 8 escalating doses of cockroach extract (0.00381-11.9 µg/mL Bla g 1). NAC outcome was determined by Total Nasal Symptom Score (TNSS) and/or sneeze score. Cockroach allergen-induced T-cell activation and IL-5 production were measured in peripheral blood mononuclear cells.Results67% (6/9) of adults and 68% (17/25) of children had a positive NAC at a median response dose of 0.120 µg/mL [IQR 0.0380-0.379 µg/mL] of Bla g 1. Additionally, three children responded to diluent alone and did not receive any cockroach extract. Overall, 32% (11/34) were positive with sneezes alone, 15% (5/34) with TNSS alone, and 21% (7/34) with both criteria. At baseline, NAC responders had higher cockroach-specific IgE (P = .03), lower cockroach-specific IgG/IgE ratios (children, P = .002), and increased cockroach-specific IL-5-producing T lymphocytes (P = .045). The NAC was well tolerated.ConclusionWe report the methodology of NAC development for children with persistent asthma and cockroach sensitization. This NAC could be considered a tool to confirm clinically relevant sensitization and to assess responses in therapeutic studies.
| S-EPMC8503840 | biostudies-literature
Project description:PurposeCockroach feces are known to be rich in IgE-reactive components. Various protease allergens were identified by proteomic analysis of German cockroach fecal extract in a previous study. In this study, we characterized a novel allergen, a chymotrypsin-like serine protease.MethodsA cDNA sequence homologous to chymotrypsin was obtained by analysis of German cockroach expressed sequence tag (EST) clones. The recombinant chymotrypsins from the German cockroach and house dust mite (Der f 6) were expressed in Escherichia coli using the pEXP5NT/TOPO vector system, and their allergenicity was investigated by ELISA.ResultsThe deduced amino acid sequence of German cockroach chymotrypsin showed 32.7 to 43.1% identity with mite group 3 (trypsin) and group 6 (chymotrypsin) allergens. Sera from 8 of 28 German cockroach allergy subjects (28.6%) showed IgE binding to the recombinant protein. IgE binding to the recombinant cockroach chymotrypsin was inhibited by house dust mite chymotrypsin Der f 6, while it minimally inhibited the German cockroach whole body extract.ConclusionsA novel allergen homologous to chymotrypsin was identified from the German cockroach and was cross-reactive with Der f 6.
| S-EPMC4397369 | biostudies-literature
Project description:German cockroach (GCr) allergens induce IgE responses and may cause asthma. Commercial GCr allergen extracts are variable and existing assays may not be appropriate for determining extract composition and potency.Our aim was to develop a multiplex antibody/bead-based assay for assessment of GCr allergen extracts.Single chain fragment variable (scFv) antibodies against GCr were obtained by screening libraries derived from naïve human lymphocytes and hyperimmunized chicken splenocytes and bone marrow. Selected clones were sequenced and characterized by immunoblotting. Eighteen scFv antibodies (17 chicken, 1 human) coupled to polystyrene beads were used in this suspension assay; binding of targeted GCr allergens to antibody-coated beads was detected using rabbit antisera against GCr, and against specific allergens rBla g 1, rBla g 2, and rBla g 4. The assay was tested for specificity, accuracy, and precision. Extracts were also compared by IgE competition ELISA.Chicken scFv's generated eight different binding patterns to GCr proteins from 14 to 150 kDa molecular weight. Human scFv's recognized a 100 kDa GCr protein. The multiplex assay was found to be specific and reproducible with intra-assay coefficient of variation (CV) of 2.64% and inter-assay CV of 10.0%. Overall potencies of various GCr extracts were calculated using mean logEC50s for eight selected scFvs. Overall potency measures were also analyzed by assessing the contributions to potency of each target.An scFv antibody-based multiplex assay has been developed capable of simultaneously measuring different proteins in a complex mixture, and to determine the potencies and compositions of allergen extracts.
| S-EPMC4596881 | biostudies-literature
Project description:BackgroundCockroach is an important allergen in inner-city asthma. The diagnosis and treatment of cockroach allergy has been impeded by the lack of standardized cockroach extracts.ObjectiveWe investigated the utility of a mediator release assay based on rat basophil leukemia (RBL) cells for comparing the potency of German cockroach extracts.MethodsRBL cells (line 2H3) transfected with human FcepsilonRI were passively sensitized with sera from subjects with cockroach allergy and stimulated with serial dilutions of 3 commercial cockroach extracts (1:10 weight/volume). In addition, the in-house prepared extract was tested in separate experiments with pooled sera that produced optimal performance in the RBL assay. N-hexosaminidase release (NHR) was used as a marker of RBL cell degranulation and was examined in relation to the intradermal skin test (ID(50)EAL) and serum cockroach-specific and total IgE levels.ResultsThe median cockroach-specific IgE concentration in 60 subjects was 0.72 kU(A)/L (interquartile range, 0.35-2.97 kU(A)/L); 19 sera (responders) produced a minimum 10% NHR to more than 1 extract. Responders had higher median cockroach-specific IgE (7.4 vs 1.0 kU(A)/L) and total IgE (429 vs 300 kU/L) levels than nonresponders. Ranking of extract potency was consistent between the mediator release assay and the ID(50)EAL. For the in-house prepared cockroach extract, the dose-response curves were shifted according to the concentration of the extract. NHR was reproducible between different experiments by using pooled sera.ConclusionThe mediator release assay measures biologic potency and correlates with the ID(50)EAL. It should be further evaluated to determine whether it could be used to replace intradermal skin test titration for assessing the potency of cockroach extract.
| S-EPMC2952833 | biostudies-literature
Project description:The Gauging Response in Allergic Rhinitis to Sublingual and Subcutaneous Immunotherapy (GRASS) study was a randomized, double-blind, placebo-controlled trial of individuals with timothy grass allergy who received 2 years of placebo, subcutaneous (SCIT), or sublingual immunotherapy (SLIT) and were followed for a total of 3 years. Here we utilized longitudinal transcriptomic profiling of nasal brush and peripheral blood mononuclear cell (PBMC) samples after allergen provocation collected in the GRASS study to uncover airway and systemic expression pathways mediating responsiveness to immunotherapy.
2023-12-31 | GSE206149 | GEO
Project description:A direct comparison of NAC and EEC allergen challenges revealed differences in the kinetics and magnitude of clinical responses, but comparable immunological responses indicating similarity in the biological pathways elicited by both challenge methodologies
2020-03-12 | GSE129748 | GEO