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Hofer F, Kamenik AS, Fernández-Quintero ML, Kraml J, Liedl KR. pH-Induced Local Unfolding of the Phl p 6 Pollen Allergen From cpH-MD. Front Mol Biosci 2021; 7:603644. [PMID: 33511157 PMCID: PMC7835895 DOI: 10.3389/fmolb.2020.603644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/10/2020] [Indexed: 11/13/2022] Open
Abstract
Susceptibility to endosomal degradation is a decisive contribution to a protein's immunogenicity. It is assumed that the processing kinetics of structured proteins are inherently linked to their probability of local unfolding. In this study, we quantify the impact of endosomal acidification on the conformational stability of the major timothy grass pollen allergen Phl p 6. We use state of the art sampling approaches in combination with constant pH MD techniques to profile pH-dependent local unfolding events in atomistic detail. Integrating our findings into the current view on type 1 allergic sensitization, we characterize local protein dynamics in the context of proteolytic degradation at neutral and acidic pH for the wild type protein and point mutants with varying proteolytic stability. We analyze extensive simulation data using Markov state models and retrieve highly reliable thermodynamic and kinetic information at varying pH levels. Thereby we capture the impact of endolysosomal acidification on the structure and dynamics of the Phl p 6 mutants. We find that upon protonation at lower pH values, the conformational flexibilities in key areas of the wild type protein, i.e., T-cell epitopes and early proteolytic cleavage sites, increase significantly. A decrease of the pH even leads to local unfolding in otherwise stable secondary structure elements, which is a prerequisite for proteolytic cleavage. This effect is even more pronounced in the destabilized mutant, while no unfolding was observed for the stabilized mutant. In summary, we report detailed structural models which rationalize the experimentally observed cleavage pattern during endosomal acidification.
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Hofer F, Dietrich V, Kamenik AS, Tollinger M, Liedl KR. pH-Dependent Protonation of the Phl p 6 Pollen Allergen Studied by NMR and cpH-aMD. J Chem Theory Comput 2019; 15:5716-5726. [PMID: 31476118 PMCID: PMC6994067 DOI: 10.1021/acs.jctc.9b00540] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We use state-of-the-art NMR experiments to measure apparent pKa values in the native protein environment and employ a cutting-edge combination of enhanced sampling and constant pH molecular dynamics (MD) simulations to rationalize strong pKa shifts. The major timothy grass pollen allergen Phl p 6 serves as an ideal model system for both methods due to its high number of titratable residues despite its comparably small size. We present a proton transition analysis as intuitive tool to depict the captured protonation state ensemble in atomistic detail. Combining microscopic structural details from MD simulations and macroscopic ensemble averages from NMR shifts leads to a comprehensive view on pH dependencies of protonation states and tautomers. Overall, we find striking agreement between simulation-based pKa predictions and experiment. However, our analyses suggest subtle differences in the underlying molecular origin of the observed pKa shifts. From accelerated constant pH MD simulations, we identify immediate proximity of opposite charges, followed by vicinity of equal charges as major driving forces for pKa shifts. NMR experiments on the other hand, suggest only a weak relation of pKa shifts and close contacts to charged residues, while the strongest influence derives from the dipolar character of α helices. The presented study hence pinpoints opportunities for improvements concerning the theoretical description of protonation state and tautomer probabilities. However, the coherence in the resulting apparent pKa values from simulations and experiment affirms cpH-aMD as a reliable tool to study allergen dynamics at varying pH levels.
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Affiliation(s)
- Florian Hofer
- †Institute
for General, Inorganic and Theoretical Chemistry and ‡Institute for Organic Chemistry,
Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Valentin Dietrich
- †Institute
for General, Inorganic and Theoretical Chemistry and ‡Institute for Organic Chemistry,
Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Anna S. Kamenik
- †Institute
for General, Inorganic and Theoretical Chemistry and ‡Institute for Organic Chemistry,
Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Martin Tollinger
- †Institute
for General, Inorganic and Theoretical Chemistry and ‡Institute for Organic Chemistry,
Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Klaus R. Liedl
- †Institute
for General, Inorganic and Theoretical Chemistry and ‡Institute for Organic Chemistry,
Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria,E-mail:
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Linhart B, Focke-Tejkl M, Weber M, Narayanan M, Neubauer A, Mayrhofer H, Blatt K, Lupinek C, Valent P, Valenta R. Molecular evolution of hypoallergenic hybrid proteins for vaccination against grass pollen allergy. THE JOURNAL OF IMMUNOLOGY 2015; 194:4008-18. [PMID: 25786690 DOI: 10.4049/jimmunol.1400402] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 02/15/2015] [Indexed: 11/19/2022]
Abstract
More than 10% of the population in Europe and North America suffer from IgE-associated allergy to grass pollen. In this article, we describe the development of a vaccine for grass pollen allergen-specific immunotherapy based on two recombinant hypoallergenic mosaic molecules, designated P and Q, which were constructed out of elements derived from the four major timothy grass pollen allergens: Phl p 1, Phl p 2, Phl p 5, and Phl p 6. Seventeen recombinant mosaic molecules were expressed and purified in Escherichia coli using synthetic genes, characterized regarding biochemical properties, structural fold, and IgE reactivity. We found that depending on the arrangement of allergen fragments, mosaic molecules with strongly varying IgE reactivity were obtained. Based on an extensive screening with sera and basophils from allergic patients, two hypoallergenic mosaic molecules, P and Q, incorporating the primary sequence elements of the four grass pollen allergens were identified. As shown by lymphoproliferation experiments, they contained allergen-specific T cell epitopes required for tolerance induction, and upon immunization of animals induced higher allergen-specific IgG Abs than the wild-type allergens and a registered monophosphoryl lipid A-adjuvanted vaccine based on natural grass pollen allergen extract. Moreover, IgG Abs induced by immunization with P and Q inhibited the binding of patients' IgE to natural allergens from five grasses better than IgG induced with the wild-type allergens or an extract-based vaccine. Our results suggest that vaccines based on the hypoallergenic grass pollen mosaics can be used for immunotherapy of grass pollen allergy.
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Affiliation(s)
- Birgit Linhart
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology, and Immunology, Medical University of Vienna, 1090 Vienna, Austria
| | - Margarete Focke-Tejkl
- Christian Doppler Laboratory for Allergy Research, Medical University of Vienna, 1090 Vienna, Austria
| | - Milena Weber
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology, and Immunology, Medical University of Vienna, 1090 Vienna, Austria
| | - Meena Narayanan
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology, and Immunology, Medical University of Vienna, 1090 Vienna, Austria
| | | | - Hannes Mayrhofer
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology, and Immunology, Medical University of Vienna, 1090 Vienna, Austria
| | - Katharina Blatt
- Division of Hematology and Hemostaseology, Department of Internal Medicine I, Medical University of Vienna, 1090 Vienna, Austria
| | - Christian Lupinek
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology, and Immunology, Medical University of Vienna, 1090 Vienna, Austria
| | - Peter Valent
- Division of Hematology and Hemostaseology, Department of Internal Medicine I, Medical University of Vienna, 1090 Vienna, Austria
| | - Rudolf Valenta
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology, and Immunology, Medical University of Vienna, 1090 Vienna, Austria; Christian Doppler Laboratory for Allergy Research, Medical University of Vienna, 1090 Vienna, Austria;
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4
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Focke-Tejkl M, Weber M, Niespodziana K, Neubauer A, Huber H, Henning R, Stegfellner G, Maderegger B, Hauer M, Stolz F, Niederberger V, Marth K, Eckl-Dorna J, Weiss R, Thalhamer J, Blatt K, Valent P, Valenta R. Development and characterization of a recombinant, hypoallergenic, peptide-based vaccine for grass pollen allergy. J Allergy Clin Immunol 2014; 135:1207-7.e1-11. [PMID: 25441634 PMCID: PMC4418753 DOI: 10.1016/j.jaci.2014.09.012] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 08/14/2014] [Accepted: 09/04/2014] [Indexed: 12/17/2022]
Abstract
Background Grass pollen is one of the most important sources of respiratory allergies worldwide. Objective This study describes the development of a grass pollen allergy vaccine based on recombinant hypoallergenic derivatives of the major timothy grass pollen allergens Phl p 1, Phl p 2, Phl p 5, and Phl p 6 by using a peptide-carrier approach. Methods Fusion proteins consisting of nonallergenic peptides from the 4 major timothy grass pollen allergens and the PreS protein from hepatitis B virus as a carrier were expressed in Escherichia coli and purified by means of chromatography. Recombinant PreS fusion proteins were tested for allergenic activity and T-cell activation by means of IgE serology, basophil activation testing, T-cell proliferation assays, and xMAP Luminex technology in patients with grass pollen allergy. Rabbits were immunized with PreS fusion proteins to characterize their immunogenicity. Results Ten hypoallergenic PreS fusion proteins were constructed, expressed, and purified. According to immunogenicity and induction of allergen-specific blocking IgG antibodies, 4 hypoallergenic fusion proteins (BM321, BM322, BM325, and BM326) representing Phl p 1, Phl p 2, Phl p 5, and Phl p 6 were included as components in the vaccine termed BM32. BM321, BM322, BM325, and BM326 showed almost completely abolished allergenic activity and induced significantly reduced T-cell proliferation and release of proinflammatory cytokines in patients' PBMCs compared with grass pollen allergens. On immunization, they induced allergen-specific IgG antibodies, which inhibited patients' IgE binding to all 4 major allergens of grass pollen, as well as allergen-induced basophil activation. Conclusion A recombinant hypoallergenic grass pollen allergy vaccine (BM32) consisting of 4 recombinant PreS-fused grass pollen allergen peptides was developed for safe immunotherapy of grass pollen allergy.
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Affiliation(s)
- Margarete Focke-Tejkl
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Milena Weber
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Katarzyna Niespodziana
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | | | | | | | | | | | | | | | - Verena Niederberger
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
| | - Katharina Marth
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Julia Eckl-Dorna
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
| | - Richard Weiss
- Department of Molecular Biology, Division of Allergy and Immunology, University of Salzburg, Salzburg, Austria
| | - Josef Thalhamer
- Department of Molecular Biology, Division of Allergy and Immunology, University of Salzburg, Salzburg, Austria
| | - Katharina Blatt
- Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna, Vienna, Austria
| | - Peter Valent
- Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna, Vienna, Austria
| | - Rudolf Valenta
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
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5
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Wallner M, Pichler U, Ferreira F. Recombinant allergens for pollen immunotherapy. Immunotherapy 2014; 5:1323-38. [PMID: 24283843 DOI: 10.2217/imt.13.114] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Specific immunotherapy (IT) represents the only potentially curative therapeutic intervention of allergic diseases capable of suppressing allergy-associated symptoms not only during treatment, but also after its cessation. Presently, IT is performed with allergen extracts, which represent a heterogeneous mixture of allergenic, as well as nonallergenic, compounds of a given allergen source. To overcome many of the problems associated with extract-based IT, strategies based on the use of recombinant allergens or derivatives thereof have been developed. This review focuses on recombinant technologies to produce allergy therapeuticals, especially for allergies caused by tree, grass and weed pollen, as they are among the most prevalent allergic disorders affecting the population of industrialized societies. The reduction of IgE-binding of recombinant allergen derivatives appears to be mandatory to increase the safety profile of vaccine candidates. Moreover, increased immunogenicity is expected to reduce the dosage regimes of the presently cumbersome treatment. In this regard, it has been convincingly demonstrated in animal models that hypoallergenic molecules can be engineered to harbor inherent antiallergenic immunologic properties. Thus, strategies to modulate the allergenic and immunogenic properties of recombinant allergens will be discussed in detail. In recent years, several successful clinical studies using recombinant wild-type or hypoallergens as active ingredients have been published and, currently, novel treatment forms with higher safety and efficacy profiles are under investigation in clinical trials. These recent developments are summarized and discussed.
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Affiliation(s)
- Michael Wallner
- Christian Doppler Laboratory for Allergy Diagnosis & Therapy, Department of Molecular Biology, University of Salzburg, Hellbrunnerstr. 34, A-5020 Salzburg, Austria
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6
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Gangl K, Niederberger V, Valenta R. Multiple grass mixes as opposed to single grasses for allergen immunotherapy in allergic rhinitis. Clin Exp Allergy 2014; 43:1202-16. [PMID: 24152153 DOI: 10.1111/cea.12128] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 03/31/2013] [Accepted: 04/08/2013] [Indexed: 12/22/2022]
Abstract
Grass pollen allergy affects approximately 40% of allergic patients. Subcutaneous allergen immunotherapy (SCIT) is the only allergen-specific and disease-modifying treatment available. Currently available therapeutic vaccines for the treatment of grass pollen allergy are based on natural grass pollen extracts which are either made from pollen of one cross-reactive grass species or from several related grass species. Clinical studies have shown that SCIT performed with timothy grass pollen extract is effective for the treatment of grass pollen allergy. Moreover, it has been demonstrated that recombinant timothy grass pollen allergens contain the majority of relevant epitopes and can be used for SCIT in clinical trials. However, recent in vitro studies have suggested that mixes consisting of allergen extracts from several related grass species may have advantages for SCIT over single allergen extracts. Here, we review current knowledge regarding the disease-relevant allergens in grass pollen allergy, available clinical studies comparing SCIT with allergen extracts from timothy grass or from mixes of several related grass species of the Pooideae subfamily, in vitro cross-reactivity studies performed with natural allergen extracts and recombinant allergens and SCIT studies performed with recombinant timothy grass pollen allergens. In vitro and clinical studies performed with natural allergen extracts reveal no relevant advantages of using multiple grass mixes as opposed to single grass pollen extracts. Several studies analysing the molecular composition of natural allergen extracts and the molecular profile of patients' immune responses after SCIT with allergen extracts indicate that the major limitation for the production of a high quality grass pollen vaccine resides in intrinsic features of natural allergen extracts which can only be overcome with recombinant allergen-based technologies.
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Affiliation(s)
- K Gangl
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
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7
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Vrtala S, Huber H, Thomas WR. Recombinant house dust mite allergens. Methods 2014; 66:67-74. [PMID: 23911838 PMCID: PMC4582397 DOI: 10.1016/j.ymeth.2013.07.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 07/12/2013] [Accepted: 07/15/2013] [Indexed: 01/07/2023] Open
Abstract
House dust mites (HDM) are a globally important source of allergen responsible for the sensitization of more than 50% of allergic patients. Specific immunotherapy with HDM extracts is effective but allergen extracts cannot be fully standardized and severe side-effects can occur during the protracted course of treatment. The introduction of molecular biological techniques into allergy research allowed the indentification of more than 20 groups of HDM allergens. Recombinant HDM allergens can be produced in defined concentrations and consistent quality and allow the development of vaccines for HDM allergy with reduced allergenic activity and retained immunogenicity. The immunotherapy trials in pollen allergic patients with recombinant pollen allergens/hypoallergenic allergen derivatives have shown that this treatment is effective and indicated that recombinant HDM vaccines might improve immunotherapy of HDM allergic patients. Here we report the steps for the development of vaccines for HDM allergy. After selection of the most prevalent HDM species, the panel of allergens to be included into a therapeutic vaccine for HDM allergy needs to be determined. HDM allergens with high IgE-binding frequency and clinical relevance will be modified into hypoallergenic variants and evaluated for their allergenic activity and immunogenicity. Derivatives with reduced allergenic activity but with retained immunogenicity would be good candidates for a HDM vaccine for safe and efficient immunotherapy.
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Affiliation(s)
- Susanne Vrtala
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Hans Huber
- Biomay AG, Lazarettgasse 19. 1090 Vienna, Austria
| | - Wayne R Thomas
- Center for Child Health Research, University of Western Australia, Telethon Institute of Child Health Research, West Perth, Australia.
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Gómez-Casado C, Garrido-Arandia M, Gamboa P, Blanca-López N, Canto G, Varela J, Cuesta-Herranz J, Pacios LF, Díaz-Perales A, Tordesillas L. Allergenic characterization of new mutant forms of Pru p 3 as new immunotherapy vaccines. Clin Dev Immunol 2013; 2013:385615. [PMID: 24324505 PMCID: PMC3845429 DOI: 10.1155/2013/385615] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 09/12/2013] [Indexed: 01/08/2023]
Abstract
Nowadays, treatment of food allergy only considered the avoidance of the specific food. However, the possibility of cross-reactivity makes this practice not very effective. Immunotherapy may exhibit as a good alternative to food allergy treatment. The use of hypoallergenic molecules with reduced IgE binding capacity but with ability to stimulate the immune system is a promising tool which could be developed for immunotherapy. In this study, three mutants of Pru p 3, the principal allergen of peach, were produced based on the described mimotope and T cell epitopes, by changing the specific residues to alanine, named as Pru p 3.01, Pru p 3.02, and Pru p 3.03. Pru p 3.01 showed very similar allergenic activity as the wild type by in vitro assays. However, Pru p 3.02 and Pru p 3.03 presented reduced IgE binding with respect to the native form, by in vitro, ex vivo, and in vivo assays. In addition, Pru p 3.03 had affected the IgG4 binding capacity and presented a random circular dichroism, which was reflected in the nonrecognition by specific antibodies anti-Pru p 3. Nevertheless, both Pru p 3.02 and Pru p 3.03 maintained the binding to IgG1 and their ability to activate T lymphocytes. Thus, Pru p 3.02 and Pru p 3.03 could be good candidates for potential immunotherapy in peach-allergic patients.
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Affiliation(s)
- C. Gómez-Casado
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - M. Garrido-Arandia
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - P. Gamboa
- Servicio de Alergia, Hospital de Basurto, Bilbao, Spain
| | | | - G. Canto
- Servicio de Alergia, Hospital Infanta Leonor, Madrid, Spain
| | - J. Varela
- Servicio de Quimica de Proteinas, Centro de Investigaciones Biologicas, CSIC, Madrid, Spain
| | | | - L. F. Pacios
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
- Departamento de Biotecnología, E.T.S. Ingenieros de Montes, UPM, Madrid, Spain
| | - A. Díaz-Perales
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - L. Tordesillas
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
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Bashir MEH, Ward JM, Cummings M, Karrar EE, Root M, Mohamed ABA, Naclerio RM, Preuss D. Dual function of novel pollen coat (surface) proteins: IgE-binding capacity and proteolytic activity disrupting the airway epithelial barrier. PLoS One 2013; 8:e53337. [PMID: 23308195 PMCID: PMC3538775 DOI: 10.1371/journal.pone.0053337] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 11/27/2012] [Indexed: 11/18/2022] Open
Abstract
Background The pollen coat is the first structure of the pollen to encounter the mucosal immune system upon inhalation. Prior characterizations of pollen allergens have focused on water-soluble, cytoplasmic proteins, but have overlooked much of the extracellular pollen coat. Due to washing with organic solvents when prepared, these pollen coat proteins are typically absent from commercial standardized allergenic extracts (i.e., “de-fatted”), and, as a result, their involvement in allergy has not been explored. Methodology/Principal Findings Using a unique approach to search for pollen allergenic proteins residing in the pollen coat, we employed transmission electron microscopy (TEM) to assess the impact of organic solvents on the structural integrity of the pollen coat. TEM results indicated that de-fatting of Cynodon dactylon (Bermuda grass) pollen (BGP) by use of organic solvents altered the structural integrity of the pollen coat. The novel IgE-binding proteins of the BGP coat include a cysteine protease (CP) and endoxylanase (EXY). The full-length cDNA that encodes the novel IgE-reactive CP was cloned from floral RNA. The EXY and CP were purified to homogeneity and tested for IgE reactivity. The CP from the BGP coat increased the permeability of human airway epithelial cells, caused a clear concentration-dependent detachment of cells, and damaged their barrier integrity. Conclusions/Significance Using an immunoproteomics approach, novel allergenic proteins of the BGP coat were identified. These proteins represent a class of novel dual-function proteins residing on the coat of the pollen grain that have IgE-binding capacity and proteolytic activity, which disrupts the integrity of the airway epithelial barrier. The identification of pollen coat allergens might explain the IgE-negative response to available skin-prick-testing proteins in patients who have positive symptoms. Further study of the role of these pollen coat proteins in allergic responses is warranted and could potentially lead to the development of improved diagnostic and therapeutic tools.
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Affiliation(s)
- Mohamed Elfatih H Bashir
- Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, The University of Chicago, Chicago, Illinois, United States of America.
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10
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Casset A, Mari A, Purohit A, Resch Y, Weghofer M, Ferrara R, Thomas WR, Alessandri C, Chen KW, de Blay F, Valenta R, Vrtala S. Varying allergen composition and content affects the in vivo allergenic activity of commercial Dermatophagoides pteronyssinus extracts. Int Arch Allergy Immunol 2012; 159:253-62. [PMID: 22722650 DOI: 10.1159/000337654] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 02/22/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Diagnosis and immunotherapy of house-dust mite (HDM) allergy is still based on natural allergen extracts. The aim of this study was to analyze commercially available Dermatophagoides pteronyssinus extracts from different manufacturers regarding allergen composition and content and whether variations may affect their allergenic activity. METHODS Antibodies specific for several D. pteronyssinus allergens (Der p 1, 2, 5, 7, 10 and 21) were used to analyze extracts from 10 different manufacturers by immunoblotting. Sandwich ELISAs were used to quantify Der p 1 and Der p 2 in the extracts. Mite-allergic patients (n = 45) were skin-tested with the extracts and tested for immunoglobulin E (IgE) reactivity to a panel of 10 mite allergens (Der p 1, 2, 4, 5, 7, 8, 10, 14, 20 and 21) by dot blot. RESULTS Only Der p 1 and Der p 2 were detected in all extracts but their concentrations and ratios showed high variability (Der p 1: 6.0-40.8 µg ml(-1); Der p 2: 1.7-45.0 µg ml(-1)). At least 1 out of 4 allergens (i.e. Der p 5, 7, 10 and 21) was not detected in 8 of the studied extracts. Mite-allergic subjects showed different IgE reactivity profiles to the individual mite allergens, the extracts showed different allergenic activity in skin-prick tests and false-negative results. CONCLUSIONS Commercially available D. pteronyssinus extracts lack important allergens, show great variability regarding allergen composition and content and some gave false-negative diagnostic test results in certain patients.
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Affiliation(s)
- Anne Casset
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
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11
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Sharma V, Singh BP, Arora N. Cur l 3, a Major Allergen ofCurvularia lunata–Derived Short Synthetic Peptides, Shows Promise for Successful Immunotherapy. Am J Respir Cell Mol Biol 2011; 45:1178-84. [DOI: 10.1165/rcmb.2011-0048oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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12
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Linhart B, Valenta R. Mechanisms underlying allergy vaccination with recombinant hypoallergenic allergen derivatives. Vaccine 2011; 30:4328-35. [PMID: 22100888 DOI: 10.1016/j.vaccine.2011.11.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 10/24/2011] [Accepted: 11/03/2011] [Indexed: 10/15/2022]
Abstract
Hundred years ago therapeutic vaccination with allergen-containing extracts has been introduced as a clinically effective, disease-modifying, allergen-specific and long-lasting form of therapy for allergy, a hypersensitivity disease affecting more than 25% of the population. Today, the structures of most of the disease-causing allergens have been elucidated and recombinant hypoallergenic allergen derivatives with reduced allergenic activity have been engineered to reduce side effects during allergen-specific immunotherapy (SIT). These recombinant hypoallergens have been characterized in vitro, in experimental animal models and in clinical trials in allergic patients. This review provides a summary of the molecular, immunological and preclinical evaluation criteria applied for this new generation of allergy vaccines. Furthermore, we summarize the mechanisms underlying SIT with recombinant hypoallergens which are thought to be responsible for their therapeutic effect.
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Affiliation(s)
- Birgit Linhart
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
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13
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Protein unfolding strongly modulates the allergenicity and immunogenicity of Pru p 3, the major peach allergen. J Allergy Clin Immunol 2011; 128:1022-30.e1-7. [DOI: 10.1016/j.jaci.2011.04.020] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/15/2011] [Accepted: 04/05/2011] [Indexed: 01/03/2023]
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14
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Vrtala S, Fohr M, Campana R, Baumgartner C, Valent P, Valenta R. Genetic engineering of trimers of hypoallergenic fragments of the major birch pollen allergen, Bet v 1, for allergy vaccination. Vaccine 2011; 29:2140-8. [PMID: 21215346 DOI: 10.1016/j.vaccine.2010.12.080] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 12/13/2010] [Accepted: 12/20/2010] [Indexed: 10/18/2022]
Abstract
An immunotherapy trial performed in allergic patients with hypoallergenic recombinant fragments, comprising aa 1-74 and 75-160 of the major birch pollen allergen, Bet v 1, has indicated that the induction of allergen-specific IgG responses may be an important mechanism of this treatment. To investigate whether the immunogenicity of the rBet v 1 fragments can be increased, recombinant trimers of the fragments were produced. For this purpose, DNA trimers of rBet v 1 aa 1-74 as well as of rBet v 1 aa 75-160 were subcloned into expression plasmid pET 17b, expressed in Escherichia coli and purified. The fragments as well as the fragment trimers showed a reduced IgE-binding capacity and allergenic activity compared to rBet v 1 wildtype when tested in allergic patients. Both rBet v 1 aa 75-160 monomer and trimer induced high titers of allergen-specific IgG1 Abs in mice. Interestingly, rBet v 1 aa 1-74 trimer induced a much higher IgG(1) response to rBet v 1 than rBet v 1 aa 1-74 monomer. Consequently, IgG Abs induced with the rBet v 1 aa 1-74 trimer inhibited birch pollen allergic patients' IgE-binding 10-fold more efficiently than IgG Abs induced with the monomer. Our data show that the immunogenicity of allergy vaccines can be increased by oligomerization.
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Affiliation(s)
- Susanne Vrtala
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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15
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Schein CH, Ivanciuc O, Midoro-Horiuti T, Goldblum RM, Braun W. An Allergen Portrait Gallery: Representative Structures and an Overview of IgE Binding Surfaces. Bioinform Biol Insights 2010; 4:113-25. [PMID: 20981266 PMCID: PMC2964044 DOI: 10.4137/bbi.s5737] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Recent progress in the biochemical classification and structural determination of allergens and allergen-antibody complexes has enhanced our understanding of the molecular determinants of allergenicity. Databases of allergens and their epitopes have facilitated the clustering of allergens according to their sequences and, more recently, their structures. Groups of similar sequences are identified for allergenic proteins from diverse sources, and all allergens are classified into a limited number of protein structural families. A gallery of experimental structures selected from the protein classes with the largest number of allergens demonstrate the structural diversity of the allergen universe. Further comparison of these structures and identification of areas that are different from innocuous proteins within the same protein family can be used to identify features specific to known allergens. Experimental and computational results related to the determination of IgE binding surfaces and methods to define allergen-specific motifs are highlighted.
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Affiliation(s)
- Catherine H. Schein
- Sealy Center for Structural Biology and Molecular Biophysics
- Department of Biochemistry and Molecular Biology
- Sealy Center for Vaccine Development
- Department of Microbiology and Immunology
| | - Ovidiu Ivanciuc
- Sealy Center for Structural Biology and Molecular Biophysics
- Department of Biochemistry and Molecular Biology
| | - Terumi Midoro-Horiuti
- Department of Biochemistry and Molecular Biology
- Sealy Center for Vaccine Development
- Child Health Research Center, Department of Pediatrics, University of Texas Medical Branch, 310 University Boulevard, Galveston, Texas 77555-0364, USA
| | - Randall M. Goldblum
- Sealy Center for Structural Biology and Molecular Biophysics
- Department of Biochemistry and Molecular Biology
- Sealy Center for Vaccine Development
- Child Health Research Center, Department of Pediatrics, University of Texas Medical Branch, 310 University Boulevard, Galveston, Texas 77555-0364, USA
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics
- Department of Biochemistry and Molecular Biology
- Sealy Center for Vaccine Development
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16
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Designing hypoallergenic derivatives for allergy treatment by means of in silico mutation and screening. J Allergy Clin Immunol 2010; 125:926-934.e10. [DOI: 10.1016/j.jaci.2010.01.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2009] [Revised: 01/12/2010] [Accepted: 01/19/2010] [Indexed: 11/18/2022]
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17
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Ball T, Linhart B, Sonneck K, Blatt K, Herrmann H, Valent P, Stoecklinger A, Lupinek C, Thalhamer J, Fedorov AA, Almo SC, Valenta R. Reducing allergenicity by altering allergen fold: a mosaic protein of Phl p 1 for allergy vaccination. Allergy 2009; 64:569-80. [PMID: 19243361 DOI: 10.1111/j.1398-9995.2008.01910.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The major timothy grass pollen allergen, Phl p 1, resembles the allergenic epitopes of natural group I grass pollen allergens and is recognized by more than 95% of grass-pollen-allergic patients. Our objective was the construction, purification and immunologic characterization of a genetically modified derivative of the major timothy grass pollen allergen, Phl p 1 for immunotherapy of grass pollen allergy. METHODS A mosaic protein was generated by PCR-based re-assembly and expression of four cDNAs coding for Phl p 1 fragments and compared to the Phl p 1 wild-type by circular dichroism analysis, immunoglobulin E (IgE)-binding capacity, basophil activation assays and enzyme-linked immunosorbent assay competition assays. Immune responses to the derivative were studied in BALB/c mice. RESULTS Grass-pollen-allergic patients exhibited greater than an 85% reduction in IgE reactivity to the mosaic as compared with the Phl p 1 allergen and basophil activation experiments confirmed the reduced allergenic activity of the mosaic. It also induced less Phl p 1-specific IgE antibodies than Phl p 1 upon immunization of mice. However, immunization of mice and rabbits with the mosaic induced IgG antibodies that inhibited patients' IgE-binding to the wild-type allergen and Phl p 1-induced degranulation of basophils. CONCLUSION We have developed a strategy based on rational molecular reassembly to convert one of the clinically most relevant allergens into a hypoallergenic derivative for allergy vaccination.
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MESH Headings
- Adult
- Aged
- Allergens/biosynthesis
- Allergens/chemistry
- Allergens/immunology
- Amino Acid Sequence
- Animals
- Basophils/immunology
- Basophils/metabolism
- Desensitization, Immunologic/methods
- Epitopes, T-Lymphocyte/chemistry
- Epitopes, T-Lymphocyte/immunology
- Female
- Histamine/biosynthesis
- Histamine/immunology
- Humans
- Immunoglobulin E/blood
- Immunoglobulin E/immunology
- Immunoglobulin G/blood
- Immunoglobulin G/immunology
- Lymphocyte Activation/immunology
- Male
- Mice
- Mice, Inbred BALB C
- Middle Aged
- Molecular Sequence Data
- Plant Proteins/biosynthesis
- Plant Proteins/chemistry
- Plant Proteins/immunology
- Polymerase Chain Reaction
- Protein Structure, Quaternary
- Rabbits
- Rats
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/chemical synthesis
- Recombinant Proteins/immunology
- Rhinitis, Allergic, Seasonal/immunology
- Rhinitis, Allergic, Seasonal/prevention & control
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- T-Lymphocytes/immunology
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Affiliation(s)
- T Ball
- Department of Pathophysiology, Center for Physiology, Pathophysiology and Immunology, Medical University of Vienna, Austria
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18
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Mothes-Luksch N, Stumvoll S, Linhart B, Focke M, Krauth MT, Hauswirth A, Valent P, Verdino P, Pavkov T, Keller W, Grote M, Valenta R. Disruption of allergenic activity of the major grass pollen allergen Phl p 2 by reassembly as a mosaic protein. THE JOURNAL OF IMMUNOLOGY 2008; 181:4864-73. [PMID: 18802090 DOI: 10.4049/jimmunol.181.7.4864] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The recognition of conformational epitopes on respiratory allergens by IgE Abs is a key event in allergic inflammation. We report a molecular strategy for the conversion of allergens into vaccines with reduced allergenic activity, which is based on the reassembly of non-IgE-reactive fragments in the form of mosaic proteins. This evolution process is exemplified for timothy grass pollen-derived Phl p 2, a major allergen for more than 200 million allergic patients. In a first step, the allergen was disrupted into peptide fragments lacking IgE reactivity. cDNAs coding for these peptides were reassembled in altered order and expressed as a recombinant mosaic molecule. The mosaic molecule had lost the three-dimensional structure, the IgE reactivity, and allergenic activity of the wild-type allergen, but it induced high levels of allergen-specific IgG Abs upon immunization. These IgG Abs crossreacted with group 2 allergens from other grass species and inhibited allergic patients' IgE binding to the wild-type allergen. The mosaic strategy is a general strategy for the reduction of allergenic activity of protein allergens and can be used to convert harmful allergens into safe vaccines.
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Affiliation(s)
- Nadine Mothes-Luksch
- Division of Immunopathology, Department of Pathophysiology, Center of Physiology, Pathophysiology and Immunology, Vienna General Hospital, Medical University of Vienna, Vienna, Austria
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19
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Linhart B, Mothes-Luksch N, Vrtala S, Kneidinger M, Valent P, Valenta R. A hypoallergenic hybrid molecule with increased immunogenicity consisting of derivatives of the major grass pollen allergens, Phl p 2 and Phl p 6. Biol Chem 2008; 389:925-33. [PMID: 18627317 DOI: 10.1515/bc.2008.105] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Allergen-specific immunotherapy is currently based on the administration of allergen extracts containing natural allergens. However, its broad application is limited by the poor quality of these extracts. Based on recombinant allergens, well-defined allergy vaccines for allergen-specific immunotherapy can be produced. Furthermore, they can be modified to reduce their allergenic activity and to avoid IgE-mediated side effects. Here, we demonstrate that the immunogenicity of two grass pollen-derived hypoallergenic allergen derivatives could be increased by engineering them as a single hybrid molecule. We used a hypoallergenic Phl p 2 mosaic, generated by fragmentation of the Phl p 2 sequence and reassembly of the resulting peptides in an altered order, and a truncated Phl p 6 allergen, to produce a hybrid protein. The hybrid retained the reduction of IgE reactivity and allergenic activity of its components as shown by ELISA and basophil activation assays. Immunization with the hybrid molecule demonstrated the increased immunogenicity of this molecule, leading to higher levels of allergen-specific IgG antibodies compared to the single components. These antibodies could inhibit patients' IgE binding to the wild-type allergens. Thus, the described strategy allows the development of safer and more efficacious vaccines for the treatment of grass pollen allergy.
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Affiliation(s)
- Birgit Linhart
- Division of Immunopathology, Department of Pathophysiology, Center of Physiology, Pathophysiology and Immunology, Medical University of Vienna, Vienna, Austria.
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Chan SL, Ong TC, Gao YF, Tiong YS, Wang DY, Chew FT, Mok YK. Nuclear Magnetic Resonance Structure and IgE Epitopes of Blo t 5, a Major Dust Mite Allergen. THE JOURNAL OF IMMUNOLOGY 2008; 181:2586-96. [DOI: 10.4049/jimmunol.181.4.2586] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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Abstract
Type I allergy represents an important health problem that affects more than 25% of the population in industrialized countries. Specific immunotherapy is one of the few causative treatment approaches for type I allergy and is currently performed with crude allergen extracts, which consist of a mixture of allergenic and nonallergenic components, are difficult to standardize and cannot be applied according to the patient's reactivity profile. With the introduction of molecular biological techniques into allergy research, a large panel of individual recombinant allergens has become available. Recombinant allergens can be used for improved diagnosis of allergy to determine the patient's sensitization profile, which is a prerequisite to select the allergens for patient-tailored immunotherapy. They allow the elucidation of the properties of allergens and of the mechanisms of allergy as well as of the mechanisms of immunotherapy. Moreover, recombinant allergens allow the development of hypoallergenic allergen derivatives with reduced allergenic activity and retained immunogenicity. First immunotherapy trials with hypoallergenic allergen derivatives have shown that this treatment might improve immunotherapy in the near future. This review summarizes the results, which were obtained with recombinant allergens and hypoallergenic allergen derivatives. The experiences from the in vitro and in vivo evaluation of the hypoallergenic derivatives and from clinical studies as well as the contribution of hypoallergenic derivatives to develop new treatment strategies and possibly prophylactic vaccination strategies are discussed.
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Affiliation(s)
- S Vrtala
- Division of Immunopathology, Department for Pathophysiology, Center for Physiology and Pathophysiology, Medical University of Vienna, Vienna, Austria
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22
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Bhalla PL, Singh MB. Biotechnology-based allergy diagnosis and vaccination. Trends Biotechnol 2008; 26:153-61. [PMID: 18222557 DOI: 10.1016/j.tibtech.2007.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 11/21/2007] [Accepted: 11/21/2007] [Indexed: 10/22/2022]
Abstract
The diagnosis and immunotherapy currently applied to allergic diseases involve the use of crude extracts of the allergen source without defining the allergy-eliciting molecule(s). Advances in recombinant DNA technology have made identification, cloning, expression and epitope mapping of clinically significant allergens possible. Recombinant allergens that retain the immunological features of natural allergens form the basis of accurate protein-chip-based methods for diagnosing allergic conditions. The ability to produce rationally designed hypoallergenic forms of allergens is leading to the development of novel and safe forms of allergy vaccines with improved efficacy. The initial clinical tests on recombinant-allergen-based vaccine preparations have provided positive results, and ongoing developments in areas such as alternative routes of vaccine delivery will enhance patient compliance.
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Affiliation(s)
- Prem L Bhalla
- Plant Molecular Biology and Biotechnology Laboratory, Australian Research Council Centre of Excellence for Integrative Legume Research, Faculty of Land and Food Resources, The University of Melbourne, Parkville, Victoria, Australia.
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