Time filter

Source Type


Pomes A.,Indoor Biotechnologies
International Archives of Allergy and Immunology | Year: 2010

The 3-dimensional structure of an allergen defines the accessible parts on the surface of the molecule or epitopes that interact with antibodies. Mapping the antigenic determinants for IgE antibody binding has been pursued through strategies based on the use of overlapping synthetic peptides, recombinant allergenic fragments or unfolded allergens. These approaches led to the identification of mostly linear epitopes and are useful for food allergens that undergo digestion or food processing. For inhaled allergens, conformational epitopes appear to be the primary targets of IgE responses. Knowledge of the molecular structure of allergens alone and in complex with antibodies that interfere with IgE antibody binding is important to understand the immune recognition of B cell-antigenic determinants on allergens and the design of recombinant allergens for immunotherapy. Starting with the molecular cloning and expression of allergens, and with the advent of X-ray crystallography and nuclear magnetic resonance techniques, we have been able to visualize conformational epitopes on allergens. © 2009 S. Karger AG, Basel.

Vredegoor D.W.,University Utrecht | Willemse T.,University Utrecht | Chapman M.D.,Indoor Biotechnologies | Heederik D.J.J.,University Utrecht | Krop E.J.M.,University Utrecht
Journal of Allergy and Clinical Immunology | Year: 2012

Background: Certain dog breeds are described and marketed as being "hypoallergenic" on the basis of anecdotal reports that these dogs are better tolerated by patients allergic to dogs. Objective: These observations were investigated by comparing Can f 1 (major dog [Canis familiaris] allergen) levels in hair and coat samples and in the home environment of various hypoallergenic (Labradoodle, Poodle, Spanish Waterdog, and Airedale terrier) and non-hypoallergenic dogs (Labrador retriever and a control group). Methods: Hair and coat samples were obtained from dogs, and settled floor and airborne dust samples were taken from the dogs' homes. Can f 1 concentrations were measured by using ELISA, and results were analyzed by using multiple linear regression analyses. Results: Significantly higher Can f 1 concentrations were found in hair and coat samples of hypoallergenic dogs (n 5 196, geometric mean [GM], 2.26 mgμg, geometric standard deviation [GSD], 0.73, and GM, 27.04 mgμg, GSD, 0.57, respectively) than of non-hypoallergenic dogs (n 5 160, GM, 0.77 mgμg, GSD, 0.71, and GM, 12.98 mgμg, GSD, 0.76, respectively). Differences between breeds were small, relative to the variability within a breed. Can f 1 levels in settled floor dust samples were lower for Labradoodles, but no differences were found between the other groups. No differences in airborne levels were found between breeds. Conclusion: So-called hypoallergenic dogs had higher Can f 1 levels in hair and coat samples than did control breeds. These differences did not lead to higher levels of environmental exposure to dog allergens. There is no evidence for the classification of certain dog breeds as being "hypoallergenic." (J Allergy Clin Immunol 2012;130:904-9. © 2012 American Academy of Allergy, Asthma & Immunology.

Romeo M.J.,University of Virginia | Agrawal R.,University of Virginia | Pomes A.,Indoor Biotechnologies | Woodfolk J.A.,University of Virginia
Journal of Allergy and Clinical Immunology | Year: 2014

The cytokines IL-4, IL-13, and thymic stromal lymphopoietin play a key role in allergic disease by virtue of their ability to initiate, maintain, and augment TH2 responses. These molecules mediate their effects through type 1 cytokine receptors, which bind cytokines with a characteristic structure. Receptors are expressed on a broad array of immune cell types and are integral to complex cytokine networks operating in health and disease. T H2-promoting cytokines bind different configurations of receptors. Receptor subunits can exist in surface-bound or soluble forms, as well as in isolation or in partnership with other subunits. Sharing of receptor subunits among different cytokine receptor complexes adds to the intricate landscape. This article describes the characteristics of receptors for IL-4, IL-13, and thymic stromal lymphopoietin and their respective ligands from a structure-function perspective. We detail the mechanisms of receptor complex assembly, the interrelated nature of these receptors, and the effect on allergic inflammation. The ability for novel and atypical types of receptors to modulate inflammatory processes is also discussed. We highlight current and emerging treatments that target TH2-promoting receptor complexes. Understanding the molecular features of these receptors provides insight into different disease phenotypes and the variable clinical outcomes arising from targeted therapies. These considerations can be used to inform future directions for research and creative strategies for treating individual patients. © 2013 American Academy of Allergy, Asthma & Immunology.

Pomes A.,Indoor Biotechnologies | Arruda L.K.,University of Sao Paulo
Methods | Year: 2014

Cockroach allergy is an important health problem associated with the development of asthma, as a consequence of chronic exposure to low levels of allergens in susceptible individuals. In the last 20. years, progress in understanding the disease has been possible, thanks to the identification and molecular cloning of cockroach allergens and their expression as recombinant proteins. Assays for assessment of environmental allergen exposure have been developed and used to measure Bla g 1 and Bla g 2, as markers of cockroach exposure. IgE antibodies to cockroach extracts and to specific purified allergens have been measured to assess sensitization and analyze association with exposure and disease. With the development of the field of structural biology and the expression of recombinant cockroach allergens, insights into allergen structure, function, epitope mapping and allergen-antibody interactions have provided further understanding of mechanisms of cockroach allergic disease at the molecular level. This information will contribute to develop new approaches to allergen avoidance and to improve diagnosis and therapy of cockroach allergy. © 2013 Elsevier Inc.

Chapman M.D.,Indoor Biotechnologies | Briza P.,University of Salzburg
Current Allergy and Asthma Reports | Year: 2012

Molecular approaches to allergen standardization include the development of purified natural or recombinant allergen standards whose structural and allergenic properties have been validated, in tandem with certified immunoassays for allergen measurement. Purified allergens can be used individually or incorporated into multiple allergen standards. Multicenter international collaborative studies are required to validate candidate allergen standards and immunoassays, as a prelude to being approved by regulatory agencies. Mass spectrometry is a sophisticated and powerful proteomics tool that is being developed for allergen analysis. Recent results using pollen allergens show that mass spectrometry can identify and measure specific allergens in a complex mixture and can provide precise information of the variability of natural allergen extracts. In future, the combined use of immunoassays and mass spectrometry will provide complete standardization of allergenic products. Molecular standardization will form the basis of new allergy diagnostics and therapeutics, as well as assessment of environmental exposure, and will improve the quality of treatment options for allergic patients. © Springer Science+Business Media, LLC 2012.

Discover hidden collaborations