IgE and T cell reactivity to a comprehensive panel of cockroach allergens in relation to disease

IgE sensitization to cockroach allergens is associated with development of allergic diseases, such as asthma. To understand the relevance of different cockroach allergens for diagnosis and immunotherapy, a comprehensive analysis of IgE antibody levels and T cell reactivity to an expanded set of cockroach allergens and their relationship to disease was performed in a cohort of USA cockroach sensitized patients. IgE antibody levels to recombinant chitinase and hemocyanin were measured for 23 subjects by custom-made ImmunoCAPs and compared with IgE levels to eight cockroach allergens we previously reported for the same cohort

Heterogeneity of magnitude, allergen immunodominance, and cytokine polarization of cockroach allergen-specific T cell responses in allergic sensitized children.

Background: Characterization of allergic responses to cockroach (CR), a common aeroallergen associated with asthma, has focused mainly on IgE reactivity, but little is known about T cell responses, particularly in children. We conducted a functional evaluation of CR allergen-specific T cell reactivity in a cohort of CR allergic children with asthma. Methods: Peripheral blood mononuclear cells (PBMCs) were obtained from 71 children, with mild-to-moderate asthma who were enrolled in a CR immunotherapy (IT) clinical trial, prior to treatment initiation. PBMC were stimulated with peptide pools derived from 11 CR allergens, and CD4+ T cell responses assessed by intracellular cytokine staining. Results: Highly heterogeneous responses in T cell reactivity were observed among participants, both in terms of the magnitude of cytokine response and allergen immunodominance. Reactivity against Bla g 9 and Bla g 5 was most frequent. The phenotype of the T cell response was dominated by IL-4 production and a Th2 polarized profile in 54.9% of participants, but IFNγ production and Th1 polarization was observed in 25.3% of the participants. The numbers of regulatory CD4+ T cells were also highly variable and the magnitude of effector responses and Th2 polarization were positively correlated with serum IgE levels specific to a clinical CR extract. Conclusions: Our results demonstrate that in children with mild-to-moderate asthma, CR-specific T cell responses display a wide range of magnitude, allergen dominance, and polarization. These results will enable examination of whether any of the variables measured are affected by IT and/or are predictive of clinical outcomes

Variability in German Cockroach Extract Composition Greatly Impacts T Cell Potency in Cockroach-Allergic Donors

German cockroach extract is used clinically to evaluate allergen-specific sensitization and for subcutaneous allergen-specific immunotherapy, though there are no guidelines for standardization in its manufacture. We performed an immunological evaluation of 12 different cockroach extracts prepared from different sources and their potency to induce allergen-specific T cell reactivity. PBMC from 13 cockroach allergic donors were expanded in vitro with 12 different German cockroach extracts. After culture expansion, cells were re-stimulated with the different extracts and T cell responses were assessed by FluoroSpot (IL-5, IFNγ and IL-10 production). In parallel to the extracts, single allergen peptide pools for allergens from groups 1, 2, 4, 5, and 11 were tested to determine allergen immunodominance. Furthermore, to assess allergy specificity, PBMC from 13 non-allergic donors were also tested with the most potent extract and T cell responses were compared to the allergic cohort. Dramatic variations in T cell reactivity were observed to the different cockroach extract batches. Response magnitudes varied over 3 logs within a single donor. IL-5 production in the allergic cohort was significantly higher compared to the non-allergic cohort (p=0.004). Allergen content determination by ELISA detected much lower concentrations of Bla g 5 compared to Bla g 1 and 2. Mass spectrometric analysis revealed that Bla g 5 was present in similar amounts to Bla g 1 and 2 in extracts made from whole body, whereas it was not detected in extracts made from fecal matter, suggesting that Bla g 5 is not excreted into feces. Different donors exhibit different response patterns to different extracts, potentially dependent on the donor-specific T cell allergen immunodominance pattern and the allergen content of the extract tested. These findings have dramatic implications for the selection of potent extracts used for diagnostic purposes or allergen-specific immunotherapy

Mechanisms of Allergen-Antibody Interaction of Cockroach Allergen Bla g 2 with Monoclonal Antibodies That Inhibit IgE Antibody Binding

BACKGROUND: Cockroach allergy is strongly associated with asthma, and involves the production of IgE antibodies against inhaled allergens. Reports of conformational epitopes on inhaled allergens are limited. The conformational epitopes for two specific monoclonal antibodies (mAb) that interfere with IgE antibody binding were identified by X-ray crystallography on opposite sites of the quasi-symmetrical cockroach allergen Bla g 2. METHODOLOGY/PRINCIPAL FINDINGS: Mutational analysis of selected residues in both epitopes was performed based on the X-ray crystal structures of the allergen with mAb Fab/Fab' fragments, to investigate the structural basis of allergen-antibody interactions. The epitopes of Bla g 2 for the mAb 7C11 or 4C3 were mutated, and the mutants were analyzed by SDS-PAGE, circular dichroism, and/or mass spectrometry. Mutants were tested for mAb and IgE antibody binding by ELISA and fluorescent multiplex array. Single or multiple mutations of five residues from both epitopes resulted in almost complete loss of mAb binding, without affecting the overall folding of the allergen. Preventing glycosylation by mutation N268Q reduced IgE binding, indicating a role of carbohydrates in the interaction. Cation-π interactions, as well as electrostatic and hydrophobic interactions, were important for mAb and IgE antibody binding. Quantitative differences in the effects of mutations on IgE antibody binding were observed, suggesting heterogeneity in epitope recognition among cockroach allergic patients. CONCLUSIONS/SIGNIFICANCE: Analysis by site-directed mutagenesis of epitopes identified by X-ray crystallography revealed an overlap between monoclonal and IgE antibody binding sites and provided insight into the B cell repertoire to Bla g 2 and the mechanisms of allergen-antibody recognition, including involvement of carbohydrates

The novel structure of the cockroach allergen Bla g 1 has implications for allergenicity and exposure assessment

Zanijeti i iznijeti trudnoću u dobi preko 35 godina svakako je teže nego kod mlađih žena. Međutim, uz pravilnu skrb i nadzor tijekom trudnoće i u porodu najveći će broj žena koje se u toj dobi odluče za majčinstvo taj cilj obaviti bez većih smetnji. Posebno je važno da žene koje se na trudnoću odluče u zrelijoj dobi, a uz to boluju od nekih kroničnih bolesti, obave pregled prije planirane trudnoće, tzv. prekoncepcijsku obradu. Kod većine će pažljiv nadzor tijekom trudnoće i u porodu omogućiti optimalan ishod. Obitelj je primarna zajednica društva koja kroz razvoj pojedinca ima utjecaj i na cjelokupan razvoj društva. Stoga uloga države mora biti zaštita i pružanje blagostanja obitelji koji se postižu metodama obiteljske politike. Obiteljska politika je skup javnih politika koja provođenjem svojih mjera direktno utječe na životni standard obitelji. Na ulogu žene u obitelji utjecale su ekonomske i društvene promjene. Žene su u obitelji imale manja prava naspram muškaraca, a na njih se gledalo tradicionalno, odnosno imale su ulogu majke i kućanice. Danas i žene i muškarci imaju jednaka prava i obveze kako unutar obitelji tako i izvan nje. Životni standard obitelji može se postići poboljšanjem ekonomskog, zdravstvenog, socijalnog i ostalih standarda. Mogućnost usklađivanja obiteljskog i poslovnog života obiteljska politika pruža putem ostvarivanja raznih prava i dodataka. Među pravima najvažnija su usluge za djecu koje najviše doprinose usklađenosti. Kod zemalja s nižom razinom usluga za djecu, izražena je manja zaposlenost žena. U takvom slučaju žene u većem broju preuzimaju ulogu kućanice i majke. Iz toga proizlazi veća neusklađenost obiteljskog i poslovnog života žena u odnosu na muškarce. Zbog raznih stajališta postoji velika heterogenost između obiteljskih politika u europskim zemljama.Pregnancy over the age of 35 is certainly more difficult than in younger age. However, with proper care and supervision during pregnancy and delivery, the most of women who decide to be a mother at the age of 35 or more will not have big problems. It is important that women who have problems with chronic illnesses make an overview before they decide to become a mother. Careful monitoring during pregnancy and delivery will ensure optimal outcome to most of the women. Family is the primary community of society that through the development of an individual person has an impact on the overall development of society. Therefore, the role of the state must be the protection and provision of family welfare achieved through the methods of family policy. Family policy is a set of public policies that by implementing their measures directly affect the family living standard. Economic and social changes had an impact on the role of women in the family. Women had less rights that men and they have been regarded traditionally and had the role of mother and housewife. Today, both women and men have equal rights and obligations in the family. The family living standard can be achieved by improving economic, health, social and other standards. The ability to harmonize family life and business life is provided by family policy through the realization of various rights and benefits. Among the rights, the most important services are benefits for children. In countries with a lower level of benefits for children, women's employment is lower. In that case women are more likely to take on the role of mother and housewives. This results in a greater disparity between the family and business life of women than men. Because of the different perspectives there is a huge heterogeneity between family policies in European countries

CD spectra of natural Bla g 2 (black line) and rBla g 2-N93Q (gray dashed).

<p>CD spectra of natural Bla g 2 (black line) and rBla g 2-N93Q (gray dashed).</p

Structural environment of the lysine residues involved in cation-π interactions important for antibody binding.

<p>A) Lysine 132 interacting with the tyrosine 33 of the heavy chain of the mAb 7C11. B) Lysine 251 interacting with the tyrosine 32 of the light chain of the mAb 4C3.</p

Binding of IgE antibodies from cockroach allergic patients to rBla g 2-N93Q and epitope mutants.

<p>A) IgE binding to mAb 7C11 epitope mutants, and B) IgE binding to mAb 4C3 epitope mutants. In A and B scatter plots show median of percentages (± interquartile ranges) of IgE binding versus rBla g 2-N93Q for the sera tested (n = 8–11) Each data point was calculated as average of percentage of IgE binding (± SEM) versus the rBla g 2-N93Q for 1–4 tests per serum depending on serum availability.</p