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Zhou Y, Zhu K, Li Q, Zhou D, Ren Y, Liao Y, Cao P, Gong Y, Cui Y. Immunobiological properties and structure analysis of group 13 allergen from Blomia tropicalis and its IgE-mediated cross-reactivity. Int J Biol Macromol 2024; 254:127788. [PMID: 37926306 DOI: 10.1016/j.ijbiomac.2023.127788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/16/2023] [Accepted: 10/28/2023] [Indexed: 11/07/2023]
Abstract
Blomia tropicalis is an important species of allergenic mite. Structurally related cross-reactive allergens are involved in pathogenesis of clinical symptoms. The present study focused on recombinant allergen rBlo t 13 from B. tropicalis, including investigation of its structure, immunological properties, IgE-mediated cross-reactivity. In this work, the prokaryotic expression plasmids pET-28(a)-Blo t 13, pET-28(a)-Der f 13, and pET-28(a)-Tyr p 13 were constructed, transformed into E. coli Rosetta (DE3) pLysS, and purified by nickel affinity chromatography, respectively. By using ELISA, the IgE-binding rates were detected for rBlo t 13 and its epitope peptides, as well as the cross-reactivity among rBlo t 13, rDer f 13, and rTyr p 13. The tertiary structure of rBlo t 13 was resolved using X-ray diffraction at 2.0 Å resolution. Using IgE-ELISA, the IgE binding rate of rBlo t 13 was 60 % with Blomia tropicalis-positive sera. In the experiments of ELISA for cross-reactivity with rBlo t 13 on solid phase, the inhibition rates were 65 %, 57 % and 63 % for rBlo t 13, rDer f 13, and rTyr p 13, respectively. The structure of Blo t 13 protein contains a β-barrel structure which is composed of 10 β strands and has 2 α helices at the end of the barrel. Comparison of the tertiary structures of rBlo t 13, rDer f 13, and rTyr p 13 revealed that the β-barrel structure is highly conserved, consistent with the alignment of amino acid sequences. We obtained the recombinant protein rBlo t 13, demonstrated its cross-reactivity with Der f 13 and Tyr p 13 due to their structural similarity.
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Affiliation(s)
- Ying Zhou
- Department of Pediatrics Laboratory, The Affiliated Wuxi Children's Hospital of Jiangnan University, Wuxi 214023, PR China
| | - Keli Zhu
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China
| | - Qingqing Li
- Clinical Research Center, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, PR China
| | - Dongmei Zhou
- Clinical Research Center, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, PR China
| | - Yaning Ren
- Clinical Research Center, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, PR China
| | - Yuanfen Liao
- Clinical Research Center, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, PR China
| | - Peng Cao
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Yong Gong
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Yubao Cui
- Clinical Research Center, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214023, PR China.
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Jacquet A. The HDM allergen orchestra and its cysteine protease maestro: Stimulators of kaleidoscopic innate immune responses. Mol Immunol 2023; 156:48-60. [PMID: 36889186 DOI: 10.1016/j.molimm.2023.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/29/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023]
Abstract
House dust mite (HDM) encloses an explosive cocktail of allergenic proteins sensitizing hundreds of millions of people worldwide. To date, the innate cellular and molecular mechanism(s) orchestrating the HDM-induced allergic inflammation remains partially deciphered. Understanding the kaleidoscope of HDM-induced innate immune responses is hampered by (1) the large complexity of the HDM allergome with very diverse functional bioreactivities, (2) the perpetual presence of microbial compounds (at least LPS, β-glucan, chitin) promoting as well pro-Th2 innate signaling pathways and (3) multiple cross-talks involving structural, neuronal and immune cells. The present review provides an update on the innate immune properties, identified so far, of multiple HDM allergen groups. Experimental evidence highlights the importance of HDM allergens displaying protease or lipid-binding activities on the initiation of the allergic responses. Specifically, group 1 HDM cysteine proteases are considered as the key initiators of the allergic response through their capacities to impair the epithelial barrier integrity, to stimulate the release of pro-Th2 danger-associated molecular patterns (DAMPs) in epithelial cells, to produce super-active forms of IL-33 alarmin and to mature thrombin leading to Toll-like receptor 4 (TLR4) activation. Remarkably, the recently evidenced primary sensing of cysteine protease allergens by nociceptive neurons confirms the critical role of this HDM allergen group in the early events leading to Th2 differentiation.
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Affiliation(s)
- Alain Jacquet
- Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
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Múnera M, Martínez D, Wortmann J, Zakzuk J, Keller W, Caraballo L, Puerta L. Structural and allergenic properties of the fatty acid binding protein from shrimp Litopenaeus vannamei. Allergy 2022; 77:1534-1544. [PMID: 34695231 DOI: 10.1111/all.15154] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 04/12/2021] [Accepted: 10/04/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND The shrimp Litopenaeus vannamei is an important source of food allergens but its allergenic repertoire is poorly characterized. Cross-reactivity between crustacean and mites has been reported, with tropomyosin, the most relevant allergen involved. The aim of this study was to investigate the structural and immunological properties of a recombinant Fatty Acid Binding Protein (FABP) family from L. vannamei (LvFABP). METHODS ELISA, skin prick test (SPT) and basophil activation assays were performed to determine IgE reactivity and allergenic activity of LvFABP. LC-MS/MS and Circular Dichroism experiments were done for structural analysis. B-cell epitope mapping with overlapping peptides, and cross-inhibition studies using human sera were done to identify antigenic regions and cross-reactivity. RESULTS The recombinant LvFABP bound serum IgE from 27% of 36 shrimp allergic patients and showed allergenic activity when tested for basophil activation and SPT in a selected number of them. CD-spectroscopy of LvFABP revealed that the protein is folded with a secondary structure composed of mainly β-strands and a smaller fraction of α helices. This is consistent with molecular modelling results, which exhibit a typical β barrel fold with two α-helices and ten β-strands. Epitope mapping identified two IgE-binding antigenic regions and inhibition assays found high cross-reactivity between LvFABP and Blo t 13, mediated by the antigenic region involving amino acids 54 to 72. CONCLUSIONS Our results show that LvFABP is a shrimp allergen that cross reacts with the house dust mite allergen Blo t 13 and has allergenic activity, which suggest that it could be clinically relevant in case of shellfish allergy. This new allergen, named Lit v 13, will also help to understand basic mechanisms of sensitization to shrimp.
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Affiliation(s)
- Marlon Múnera
- Institute for Immunological Research University of Cartagena Cartagena Colombia
| | - Dalgys Martínez
- Institute for Immunological Research University of Cartagena Cartagena Colombia
| | - Judith Wortmann
- Institute of Molecular Biosciences, BioTechMed Graz University of Graz Graz Austria
| | - Josefina Zakzuk
- Institute for Immunological Research University of Cartagena Cartagena Colombia
| | - Walter Keller
- Institute of Molecular Biosciences, BioTechMed Graz University of Graz Graz Austria
| | - Luis Caraballo
- Institute for Immunological Research University of Cartagena Cartagena Colombia
| | - Leonardo Puerta
- Institute for Immunological Research University of Cartagena Cartagena Colombia
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Serum amyloid A is a soluble pattern recognition receptor that drives type 2 immunity. Nat Immunol 2020; 21:756-765. [PMID: 32572240 DOI: 10.1038/s41590-020-0698-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 04/30/2020] [Indexed: 12/11/2022]
Abstract
The molecular basis for the propensity of a small number of environmental proteins to provoke allergic responses is largely unknown. Herein, we report that mite group 13 allergens of the fatty acid-binding protein (FABP) family are sensed by an evolutionarily conserved acute-phase protein, serum amyloid A1 (SAA1), that promotes pulmonary type 2 immunity. Mechanistically, SAA1 interacted directly with allergenic mite FABPs (Der p 13 and Blo t 13). The interaction between mite FABPs and SAA1 activated the SAA1-binding receptor, formyl peptide receptor 2 (FPR2), which drove the epithelial release of the type-2-promoting cytokine interleukin (IL)-33 in a SAA1-dependent manner. Importantly, the SAA1-FPR2-IL-33 axis was upregulated in nasal epithelial cells from patients with chronic rhinosinusitis. These findings identify an unrecognized role for SAA1 as a soluble pattern recognition receptor for conserved FABPs found in common mite allergens that initiate type 2 immunity at mucosal surfaces.
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Caraballo L, Valenta R, Puerta L, Pomés A, Zakzuk J, Fernandez-Caldas E, Acevedo N, Sanchez-Borges M, Ansotegui I, Zhang L, van Hage M, Abel-Fernández E, Karla Arruda L, Vrtala S, Curin M, Gronlund H, Karsonova A, Kilimajer J, Riabova K, Trifonova D, Karaulov A. The allergenic activity and clinical impact of individual IgE-antibody binding molecules from indoor allergen sources. World Allergy Organ J 2020; 13:100118. [PMID: 32373267 PMCID: PMC7195550 DOI: 10.1016/j.waojou.2020.100118] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 02/07/2023] Open
Abstract
A large number of allergens have been discovered but we know little about their potential to induce inflammation (allergenic activity) and symptoms. Nowadays, the clinical importance of allergens is determined by the frequency and intensity of their IgE antibody binding (allergenicity). This is a rather limited parameter considering the development of experimental allergology in the last 20 years and the criteria that support personalized medicine. Now it is known that some allergens, in addition to their IgE antibody binding properties, can induce inflammation through non IgE mediated pathways, which can increase their allergenic activity. There are several ways to evaluate the allergenic activity, among them the provocation tests, the demonstration of non-IgE mediated pathways of inflammation, case control studies of IgE-binding frequencies, and animal models of respiratory allergy. In this review we have explored the current status of basic and clinical research on allergenic activity of indoor allergens and confirm that, for most of them, this important property has not been investigated. However, during recent years important advances have been made in the field, and we conclude that for at least the following, allergenic activity has been demonstrated: Der p 1, Der p 2, Der p 5 and Blo t 5 from HDMs; Per a 10 from P. americana; Asp f 1, Asp f 2, Asp f 3, Asp f 4 and Asp f 6 from A. fumigatus; Mala s 8 and Mala s 13 from M. sympodialis; Alt a 1 from A. alternata; Pen c 13 from P. chrysogenum; Fel d 1 from cats; Can f 1, Can f 2, Can f 3, Can f 4 and Can f 5 from dogs; Mus m 1 from mice and Bos d 2 from cows. Defining the allergenic activity of other indoor IgE antibody binding molecules is necessary for a precision-medicine-oriented management of allergic diseases.
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Affiliation(s)
- Luis Caraballo
- Institute for Immunological Research, University of Cartagena, Cartagena, Colombia
- Corresponding author. Institute for Immunological Research, University of Cartagena, Cartagena de Indias, Colombia.
| | - Rudolf Valenta
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- NRC Institute of Immunology FMBA of Russia, Moscow, Russian Federation
- Department of Clinical Immunology and Allergy, Laboratory of Immunopathology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Leonardo Puerta
- Institute for Immunological Research, University of Cartagena, Cartagena, Colombia
| | - Anna Pomés
- Indoor Biotechnologies, Inc. Charlottesville, VA, USA
| | - Josefina Zakzuk
- Institute for Immunological Research, University of Cartagena, Cartagena, Colombia
| | | | - Nathalie Acevedo
- Institute for Immunological Research, University of Cartagena, Cartagena, Colombia
| | - Mario Sanchez-Borges
- Allergy and Clinical Immunology Department, Centro Médico Docente La Trinidad, Caracas, Venezuela
| | - Ignacio Ansotegui
- Department of Allergy & Immunology Hospital Quironsalud Bizkaia, Bilbao, Spain
| | - Luo Zhang
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Marianne van Hage
- Department of Medicine Solna, Division of Immunology and Allergy, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Eva Abel-Fernández
- Inmunotek, Madrid, Spain and University of South Florida College of Medicine, Tampa, USA
| | - L. Karla Arruda
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Susanne Vrtala
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Mirela Curin
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Hans Gronlund
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Antonina Karsonova
- Department of Clinical Immunology and Allergy, Laboratory of Immunopathology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Jonathan Kilimajer
- Inmunotek, Madrid, Spain and University of South Florida College of Medicine, Tampa, USA
| | - Ksenja Riabova
- Department of Clinical Immunology and Allergy, Laboratory of Immunopathology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Daria Trifonova
- Department of Clinical Immunology and Allergy, Laboratory of Immunopathology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Alexander Karaulov
- Department of Clinical Immunology and Allergy, Laboratory of Immunopathology, Sechenov First Moscow State Medical University, Moscow, Russia
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Jacquet A, Robinson C. Proteolytic, lipidergic and polysaccharide molecular recognition shape innate responses to house dust mite allergens. Allergy 2020; 75:33-53. [PMID: 31166610 DOI: 10.1111/all.13940] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/05/2019] [Accepted: 05/23/2019] [Indexed: 02/06/2023]
Abstract
House dust mites (HDMs) are sources of an extensive repertoire of allergens responsible for a range of allergic conditions. Technological advances have accelerated the identification of these allergens and characterized their putative roles within HDMs. Understanding their functional bioactivities is illuminating how they interact with the immune system to cause disease and how interrelations between them are essential to maximize allergic responses. Two types of allergen bioactivity, namely proteolysis and peptidolipid/lipid binding, elicit IgE and stimulate bystander responses to unrelated allergens. Much of this influence arises from Toll-like receptor (TLR) 4 or TLR2 signalling and, in the case of protease allergens, the activation of additional pleiotropic effectors with strong disease linkage. Of related interest is the interaction of HDM allergens with common components of the house dust matrix, through either their binding to allergens or their autonomous modulation of immune receptors. Herein, we provide a contemporary view of how proteolysis, lipid-binding activity and interactions with polysaccharides and polysaccharide molecular recognition systems coordinate the principal responses which underlie allergy. The power of the catalytically competent group 1 HDM protease allergen component is demonstrated by a review of disclosures surrounding the efficacy of novel inhibitors produced by structure-based design.
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Affiliation(s)
- Alain Jacquet
- Center of Excellence in Vaccine Research and Development (Chula Vaccine Research Center-Chula VRC) Chulalongkorn University Bangkok Thailand
| | - Clive Robinson
- Institute for Infection and Immunity St George's, University of London London UK
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Identification of B Cell Epitopes of Blo t 13 Allergen and Cross-Reactivity with Human Adipocytes and Heart Fatty Acid Binding Proteins. Int J Mol Sci 2019; 20:ijms20246107. [PMID: 31817065 PMCID: PMC6940925 DOI: 10.3390/ijms20246107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/29/2019] [Accepted: 11/29/2019] [Indexed: 12/25/2022] Open
Abstract
Cross-reactivity between allergens and human proteins could have a clinical impact in allergic diseases. Blo t 13 is an allergen from the mite Blomia tropicalis, which belongs to the fatty acid binding protein (FABP) family and has structural homology with human FABPs. This work aimed to map B cell epitopes on Blo t 13 and to identify epitopes involved in cross-reactivity with human heart FABP (FABP3) and adipocyte FABP (FABP4). Sera from 25 patients with house dust mite (HDM) allergy that were sensitized to Blo t 13 were used for testing the reactivity of immunoglobulin E (IgE) and IgG to FABP. The epitope mapping of Blo t 13 was performed using overlapping peptides, and cross-reactivity between Blo t 13 and human FABP was analyzed using human sera and anti-Blo t 13 monoclonal antibodies. IgE antibodies to all FABPs were detected in 14/25 serum samples, and IgG was detected in 25/25 serum samples. The cross-reactivity of Blo t 13 was 42% with FABP3 and 48% with FABP4. Two IgE-binding regions were identified in Blo t 13; one between residues 54 and 72 (the main cross-reacting region) and another between residues 111 to 129. Our results suggest that exposure to the Blo t 13 allergen could induce an auto-reactive response to endogenous FABP in allergic patients sensitized to Blo t 13.
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Pulsawat P, Soongrung T, Satitsuksanoa P, Le Mignon M, Khemili S, Gilis D, Nony E, Kennedy MW, Jacquet A. The house dust mite allergen Der p 5 binds lipid ligands and stimulates airway epithelial cells through a TLR2-dependent pathway. Clin Exp Allergy 2018; 49:378-390. [PMID: 30230051 DOI: 10.1111/cea.13278] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/25/2018] [Accepted: 07/29/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND Protein crystallographic studies suggest that the house dust mite (HDM) allergen Der p 5 potentially interacts with hydrophobic ligands. Der p 5, in association with its ligand(s), might therefore trigger innate immune signalling pathways in the airway epithelium and influence the initiation of the HDM-allergic response. OBJECTIVE We investigated the lipid binding propensities of recombinant (r)Der p 5 and characterized the signalling pathways triggered by the allergen in airway epithelial cells. METHODS rDer p 5 was produced in Pichia pastoris and characterized by mass spectrometry, multi-angle light scattering and circular dichroism. Its interactions with hydrophobic ligands were investigated in fluorescence-based lipid binding assays and in-silico docking simulations. Innate immune signalling pathways triggered by rDer p 5 were investigated in airway epithelial cell activation assays in vitro. RESULTS Biophysical analysis showed that rDer p 5 was monomeric and adopted a similar α-helix-rich fold at both physiological and acidic pH. Spectrofluorimetry experiments showed that rDer p 5 is able to selectively bind lipid ligands, but only under mild acidic pH conditions. Computer-based docking simulations identified potential binding sites for these ligands. This allergen, with putatively associated lipid(s), triggered the production of IL-8 in respiratory epithelial cells through a TLR2-, NF-kB- and MAPK-dependent signalling pathway. CONCLUSIONS AND CLINICAL RELEVANCE Despite the fact that Der p 5 represents a HDM allergen of intermediate prevalence, our findings regarding its lipid binding and activation of TLR2 indicate that it could participate in the initiation of the HDM-allergic state.
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Affiliation(s)
- Pinya Pulsawat
- Faculty of Medicine, Chula Vaccine Research Center, Chulalongkorn University, Bangkok, Thailand
| | - Tewarit Soongrung
- Faculty of Medicine, Chula Vaccine Research Center, Chulalongkorn University, Bangkok, Thailand
| | | | | | - Souad Khemili
- BIO-Bioinfo Department, Université Libre de Bruxelles, Brussels, Belgium.,Laboratoire Valorisation et Conservation des Ressources Biologiques (VALCOR), Faculté des Sciences, Université M'Hamed Bougara de Boumerdes, Boumerdès, Algeria
| | - Dimitri Gilis
- BIO-Bioinfo Department, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Malcolm W Kennedy
- Institute of Biodiversity, Animal Health and Comparative Medicine, School of Life Sciences, University of Glasgow, Glasgow, UK
| | - Alain Jacquet
- Faculty of Medicine, Chula Vaccine Research Center, Chulalongkorn University, Bangkok, Thailand
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Soongrung T, Mongkorntanyatip K, Peepim T, Buaklin A, Le Mignon M, Malainual N, Nony E, Jacquet A. The Blomia tropicalis allergen Blo t 7 stimulates innate immune signalling pathways through TLR2. Clin Exp Allergy 2018; 48:464-474. [PMID: 29356186 DOI: 10.1111/cea.13098] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/21/2017] [Accepted: 12/23/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Although the house dust mite species Blomia tropicalis is a leading cause of allergic diseases in tropical and subtropical regions, the identification and characterization of the allergenic proteins remain incomplete. OBJECTIVE We aimed to characterize a recombinant form of Blo t 7 (rBlo t 7) in terms of IgE reactivity, lipid-binding activity and ability to stimulate innate immunity. METHODS The mature Blo t 7 cDNA was cloned by PCR methods for the expression of a secreted form of the allergen in P. pastoris. The IgE reactivity to purified rBlo t 7 as well as the potential cross-reactivity with Der p 7 was determined by ELISA. The lipid-binding capacity of rBlo t 7 was assayed using fluorescent lipid probes. The stimulation of TLR2 signalling pathway by rBlo t 7 was examined in cell activation and reporter assays. RESULTS The amplified mature Blo t 7 cDNA revealed the presence of a 60 base pair insertion compared with the reference sequence registered in the GenBank database. Multiple protein sequence alignments of group 7 mite allergens confirmed that this longer deduced amino acid sequence was the authentic Blo t 7 polypeptide chain. Analysis of IgE reactivity can classify rBlo t 7 as an intermediate B. tropicalis allergen which displayed weak cross-reactivity with Der p 7. Purified rBlo t 7 was shown to bind selectively the naturally fluorescent lipid probe cis-parinaric (cPNA) with a dissociation constant of 2 μmol/L. The group 7 Blomia allergen stimulated the TLR2-, NF-kB- and MAPK-dependent production of IL-8 and GM-CSF in respiratory epithelial cells. CONCLUSIONS & CLINICAL RELEVANCE Through its propensity to transport fatty acids/lipids and to stimulate TLR2 signalling pathways in airway epithelial cells, Blo t 7 can represent a key allergen for the initiation of the B. tropicalis-induced airway inflammation.
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Affiliation(s)
- T Soongrung
- Chula Vaccine Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - K Mongkorntanyatip
- Chula Vaccine Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - T Peepim
- Chula Vaccine Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - A Buaklin
- Chula Vaccine Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | | | - N Malainual
- Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - E Nony
- Stallergenes-Greer, Antony, France
| | - A Jacquet
- Chula Vaccine Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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[Blomia tropicalis: A house dust mite in the tropics]. Rev Mal Respir 2017; 34:791-801. [PMID: 28502519 DOI: 10.1016/j.rmr.2016.10.877] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 10/14/2016] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Blomia tropicalis is a mite that belongs to the superfamily of Glycyphagidae. Initially described as a storage mite, it is now considered as a house dust mite of tropical and sub-tropical areas. STATE OF THE ART Sensitization to this mite is very common in South America and Southeast Asia. Epidemiological studies have also found sensitization to this mite in Africa and Central America. Blo t 5 is the major allergen of B. tropicalis. Co-sensitization to other house dust mites such as Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) is very common. Cross-reactivity has been described but recombinant allergens revealed by molecular biology techniques do not explain this cross-reactivity. Sensitization to B. tropicalis seems to begin at the age of 36 months, the incidence increases until adulthood, and decreases from the age of 50. The involvement of B. tropicalis in allergic rhinitis and asthma is well described. It is also implicated in other allergic diseases. Few studies have assessed the therapeutic strategies available against this mite but immunotherapy is widely used. PERSPECTIVES Studies are needed to better understand the role of B. tropicalis in human diseases and to develop specific treatments.
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Santos da Silva E, Asam C, Lackner P, Hofer H, Wallner M, Silva Pinheiro C, Alcântara-Neves NM, Ferreira F. Allergens of Blomia tropicalis: An Overview of Recombinant Molecules. Int Arch Allergy Immunol 2017; 172:203-214. [PMID: 28456805 PMCID: PMC5472214 DOI: 10.1159/000464325] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Allergic diseases are considered a major problem for healthcare systems in both developed and developing countries. House dust mites are well-known triggers of allergic manifestations. While the Dermatophagoides genus is widely distributed globally, Blomia tropicalis is the most prominent mite species in the tropical and subtropical regions of the world. Over the last decades, an increase in sensitization rates to B. tropicalis has been reported, leading to increased research efforts on Blomia allergens. In fact, 8 new allergens have been identified and characterized to different degrees. Here, we provide an overview of recent developments concerning the identification and production of recombinant Blomia allergens, as well as their structural and immunological characterization. Although considerable progress has been achieved, detailed molecule-based studies are still needed to better define the clinical relevance of Blomia allergens. Thus, the establishment of a well-standardized and fully characterized panel of allergens remains a challenge for the development of better diagnosis and therapy of allergic diseases induced by B. tropicalis.
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Affiliation(s)
- Eduardo Santos da Silva
- Laboratório de Alergia e Acarologia, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Recife, Brazil
- Programa de Pós-Graduação em Biotecnologia da Rede Nordeste de Biotecnologia (RENORBIO), Recife, Brazil
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Claudia Asam
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Peter Lackner
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Heidi Hofer
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Michael Wallner
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Carina Silva Pinheiro
- Laboratório de Alergia e Acarologia, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Recife, Brazil
| | - Neuza Maria Alcântara-Neves
- Laboratório de Alergia e Acarologia, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Recife, Brazil
- Programa de Pós-Graduação em Biotecnologia da Rede Nordeste de Biotecnologia (RENORBIO), Recife, Brazil
| | - Fatima Ferreira
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
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Satitsuksanoa P, Kennedy M, Gilis D, Le Mignon M, Suratannon N, Soh WT, Wongpiyabovorn J, Chatchatee P, Vangveravong M, Rerkpattanapipat T, Sangasapaviliya A, Piboonpocanun S, Nony E, Ruxrungtham K, Jacquet A. The minor house dust mite allergen Der p 13 is a fatty acid-binding protein and an activator of a TLR2-mediated innate immune response. Allergy 2016; 71:1425-34. [PMID: 27018864 DOI: 10.1111/all.12899] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2016] [Indexed: 01/15/2023]
Abstract
BACKGROUND The house dust mite (HDM) allergen Der p 13 could be a lipid-binding protein able to activate key innate signaling pathways in the initiation of the allergic response. We investigated the IgE reactivity of recombinant Der p 13 (rDer p 13), its lipid-binding activities, and its capacity to stimulate airway epithelium cells. METHODS Purified rDer p 13 was characterized by mass spectrometry, circular dichroism, fluorescence-based lipid-binding assays, and in silico structural prediction. IgE-binding activity and allergenic potential of Der p 13 were examined by ELISA, basophil degranulation assays, and in vitro airway epithelial cell activation assays. RESULTS Protein modeling and biophysical analysis indicated that Der p 13 adopts a β-barrel structure with a predominately apolar pocket representing a potential binding site for hydrophobic ligands. Fluorescent lipid-binding assays confirmed that the protein is highly selective for ligands and that it binds a fatty acid with a dissociation constant typical of lipid transporter proteins. The low IgE-binding frequency (7%, n = 224) in Thai HDM-allergic patients as well as the limited propensity to activate basophil degranulation classifies Der p 13 as a minor HDM allergen. Nevertheless, the protein with its presumptively associated lipid(s) triggered the production of IL-8 and GM-CSF in respiratory epithelial cells through a TLR2-, MyD88-, NF-kB-, and MAPK-dependent signaling pathway. CONCLUSIONS Although a minor allergen, Der p 13 may, through its lipid-binding capacity, play a role in the initiation of the HDM-allergic response through TLR2 activation.
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Affiliation(s)
- P. Satitsuksanoa
- Division of Allergy and Clinical Immunology; Department of Medicine; and Chula Vaccine Research Center (Chula VRC); Faculty of Medicine; Chulalongkorn University; Bangkok Thailand
| | - M. Kennedy
- Institute of Biodiversity, Animal Health and Comparative Medicine; College of Medical, Veterinary and Life Sciences; University of Glasgow; Glasgow UK
| | - D. Gilis
- BIO-Bioinfo Department; Université Libre de Bruxelles; Brussels Belgium
| | | | - N. Suratannon
- Division of Allergy and Immunology; Department of Pediatrics; Faculty of Medicine; Chulalongkorn University; Bangkok Thailand
| | - W. T. Soh
- Division of Allergy and Clinical Immunology; Department of Medicine; and Chula Vaccine Research Center (Chula VRC); Faculty of Medicine; Chulalongkorn University; Bangkok Thailand
| | - J. Wongpiyabovorn
- Center of Excellence in Immunology and Immune Mediated Diseases; Division of Immunology; Department of Microbiology; Faculty of Medicine; Chulalongkorn University; Bangkok Thailand
| | - P. Chatchatee
- Division of Allergy and Immunology; Department of Pediatrics; Faculty of Medicine; Chulalongkorn University; Bangkok Thailand
| | - M. Vangveravong
- Allergy, Immunology and Rheumatology Unit; Queen Sirikit National Institute of Child Health; Department of Medical Services; Ministry of Public Health; Bangkok Thailand
| | - T. Rerkpattanapipat
- Division of Allergy, Immunology and Rheumatology; Department of Medicine; Faculty of Medicine; Ramathibodi Hospital; Mahidol University; Bangkok Thailand
| | - A. Sangasapaviliya
- Division of Allergy and Clinical Immunology; Department of Medicine; Phramongkutklao Hospital; Bangkok Thailand
| | - S. Piboonpocanun
- Institute of Molecular Biosciences; Mahidol University; Nakhon Pathom Thailand
| | - E. Nony
- Stallergenes Greer; Antony France
| | - K. Ruxrungtham
- Division of Allergy and Clinical Immunology; Department of Medicine; and Chula Vaccine Research Center (Chula VRC); Faculty of Medicine; Chulalongkorn University; Bangkok Thailand
| | - A. Jacquet
- Division of Allergy and Clinical Immunology; Department of Medicine; and Chula Vaccine Research Center (Chula VRC); Faculty of Medicine; Chulalongkorn University; Bangkok Thailand
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Zakzuk J, Benedetti I, Fernández-Caldas E, Caraballo L. The influence of chitin on the immune response to the house dust mite allergen Blo T 12. Int Arch Allergy Immunol 2013; 163:119-29. [PMID: 24335274 DOI: 10.1159/000356482] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Accepted: 10/16/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Information about the biological properties of Blomia tropicalis allergens is scarce. It is predicted that Blo t 12, an allergen with two described isoforms, contains a chitin-binding domain, similar to that found in peritrophins. Th2 adjuvant properties have been described for chitin. Therefore, it is feasible that binding to this carbohydrate influences its allergenicity. We aimed to evaluate the chitin-binding activity of Blo t 12 isoallergens and its effect on airway inflammation and antibody responses in a murine model of allergen sensitization. METHODS Chitin-binding assays were conducted with the recombinant isoallergens Blo t 12.0101 and Blo t 12.0102. BALB/c mice were sensitized via i.p. with any of the two isoforms (alone, with chitin or alum) and then challenged intranasally. Methacholine-induced bronchial hyperreactivity was tested by whole-body plethysmography and lung sections were stained with hematoxylin and eosin and periodic-acid Schiff. Total IgE and allergen-specific IgE, IgG1 and IgG2 levels were measured by ELISA. RESULTS The two isoforms bound chitin, but Blo t 12.0101 showed a stronger binding capacity. Both isoforms induced total and allergen-specific IgE, airway hyperreactivity, bronchial inflammation and mucus secretion without any adjuvant; however, when administered with chitin, Blo t 12.0101 induced higher total IgE levels. The IgG1/IgG2a ratio was significantly higher in mice immunized with Blo t 12.0101 than those immunized with Blo t 12.0102. As peritrophins, Blo t 12 was detected in mite feces. CONCLUSIONS Blo t 12 isoforms are chitin-binding proteins that induce airway inflammation and bronchial hyperreactivity. However, for Blo t 12.0101, chitin reinforces its effects on total IgE production.
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Affiliation(s)
- Josefina Zakzuk
- Institute for Immunological Research, University of Cartagena, Cartagena, Colombia
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Zheng Y, Blair D, Bradley JE. Phyletic distribution of fatty acid-binding protein genes. PLoS One 2013; 8:e77636. [PMID: 24155969 PMCID: PMC3796463 DOI: 10.1371/journal.pone.0077636] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 09/13/2013] [Indexed: 01/13/2023] Open
Abstract
Fatty acid-binding proteins (FABPs) are a family of fatty acid-binding small proteins essential for lipid trafficking, energy storage and gene regulation. Although they have 20 to 70% amino acid sequence identity, these proteins share a conserved tertiary structure comprised of ten beta sheets and two alpha helixes. Availability of the complete genomes of 34 invertebrates, together with transcriptomes and ESTs, allowed us to systematically investigate the gene structure and alternative splicing of FABP genes over a wide range of phyla. Only in genomes of two cnidarian species could FABP genes not be identified. The genomic loci for FABP genes were diverse and their genomic structure varied. In particular, the intronless FABP genes, in most of which the key residues involved in fatty acid binding varied, were common in five phyla. Interestingly, several species including one trematode, one nematode and four arthropods generated FABP mRNA variants via alternative splicing. These results demonstrate that both gene duplication and post-transcriptional modifications are used to generate diverse FABPs in species studied.
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Affiliation(s)
- Yadong Zheng
- School of Biology, University of Nottingham, Nottingham, United Kingdom
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, CAAS, Lanzhou, Gansu, China
| | - David Blair
- James Cook University, Townsville, Queensland, Australia
| | - Janette E. Bradley
- School of Biology, University of Nottingham, Nottingham, United Kingdom
- * E-mail:
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15
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McNair CM, Billingsley PF, Nisbet AJ, Knox DP. Feeding-associated gene expression in sheep scab mites (Psoroptes ovis). Vet Res 2009; 41:16. [PMID: 19852923 PMCID: PMC2789330 DOI: 10.1051/vetres/2009064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Accepted: 10/22/2009] [Indexed: 11/14/2022] Open
Abstract
The mite Psoroptes ovis is the causative agent of sheep scab. Although not usually fatal, the disease can spread rapidly and is a serious animal welfare concern. Vaccine development against ectoparasites has primarily focussed on two sources of candidate vaccine antigens – “exposed” antigens that are secreted in saliva during feeding on a host and “concealed” antigens that are usually expressed in the parasite gut and may be involved in digestion. Here, we sought to identify genes encoding proteins important for mite feeding and digestion by a subtractive suppressive hybridisation approach comparing mRNA transcript abundance in “fed” and “starved” mites. The study identified a variety of genes which are up-regulated by feeding mites. These included group 1, 5, 7 and 13 allergens including the previously described cysteine protease Pso o 1. In addition, numerous novel genes were identified here including some encoding potential salivary gland proteins and others encoding proteins which may facilitate feeding such as a serum opacity factor. An olfactory receptor-like protein was identified in the starved mite population which may help the mite to identify a host.
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Affiliation(s)
- Carol M McNair
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, nr Edinburgh EH26 0PZ, United Kingdom
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Brusic V, Petrovsky N, Gendel SM, Millot M, Gigonzac O, Stelman SJ. Computational tools for the study of allergens. Allergy 2003; 58:1083-92. [PMID: 14616117 DOI: 10.1034/j.1398-9995.2003.00224.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Allergy is a major cause of morbidity worldwide. The number of characterized allergens and related information is increasing rapidly creating demands for advanced information storage, retrieval and analysis. Bioinformatics provides useful tools for analysing allergens and these are complementary to traditional laboratory techniques for the study of allergens. Specific applications include structural analysis of allergens, identification of B- and T-cell epitopes, assessment of allergenicity and cross-reactivity, and genome analysis. In this paper, the most important bioinformatic tools and methods with relevance to the study of allergy have been reviewed.
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Affiliation(s)
- V Brusic
- Institute for Infocomm Research, Singapore
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García Robaina JC, Sánchez Machín I, Fernández-Caldas E, Iraola Calvo V, Vázquez Moncholi C, Bonnet Moreno C, de la Torre Morín F. Skin tests and conjunctival and bronchial challenges with extracts of Blomia tropicalis and Dermatophagoides pteronyssinus in patients with allergic asthma and/or rhinoconjunctivitis. Int Arch Allergy Immunol 2003; 131:182-8. [PMID: 12876408 DOI: 10.1159/000071484] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2002] [Accepted: 04/07/2003] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Blomia tropicalis and Dermatophagoides pteronyssinus are important mite species in Tenerife, Canary Islands, Spain. Several studies have demonstrated a variable degree of allergenic cross-reactivity in vitro. However, only a few have addressed their allergenic cross-reactivity using challenge tests. OBJECTIVE The objective of this study was to conduct conjunctival and bronchial challenge tests with B. tropicalis and D. pteronyssinus extracts in a group of 42 patients with allergic asthma and/or rhinoconjunctivitis sensitised to house dust mites (31 females, 11 males; mean age 21.7 +/- 7.02 years). METHODS Prick tests using standardised extracts and specific IgE determinations using the CAP system were performed. Bronchial and/or conjunctival challenges were conducted using freeze-dried extracts of both mite species. A patient was considered sensitive to a mite species if she/he had a positive prick and/or CAP test result. A total of 32 conjunctival and 15 bronchial challenges were performed with both mite species. RESULTS Prick tests were positive to B. tropicalis in 23 patients (54.7%) and to D. pteronyssinus in 41 (97.6%). One patient (2.4%) was exclusively sensitive to B. tropicalis. The CAP test was positive for B. tropicalis in 28 patients and for D. pteronyssinus in 41. Conjunctival challenges to B. tropicalis were positive in 20 patients (18 sensitised and 2 non-sensitised) and negative in 12 (5 sensitised and 7 non-sensitised patients). Conjunctival challenges with D. pteronyssinus were positive in all 31 D. pteronyssinus-sensitised patients who underwent conjunctival challenges. Bronchial challenges with B. tropicalis were positive in 9 sensitised patients and negative in 6 patients (2 sensitised and 4 non-sensitised). Bronchial challenges with D. pteronyssinus were positive in all patients except 1, who only reacted to B. tropicalis. CONCLUSIONS Allergens of the mite species B. tropicalis induce positive conjunctival and bronchial challenges in B. tropicalis-sensitised individuals. Our results suggest that although there is a low to moderate degree of in vivo cross-reactivity between B. tropicalis and D. pteronyssinus, B. tropicalis seems to be a relevant source of allergens in areas where patients are exposed.
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Affiliation(s)
- J C García Robaina
- Servicio Alergia, Hospital Universitario Nuestra Señora de la Candelaria, Tenerife, Canary Islands, Spain.
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Flores I, Mora C, Rivera E, Donnelly R, Montealegre F. Cloning and molecular characterization of a cDNA from Blomia tropicalis homologous to dust mite group 3 allergens (trypsin-like proteases). Int Arch Allergy Immunol 2003; 130:12-6. [PMID: 12576730 DOI: 10.1159/000068375] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2002] [Accepted: 10/29/2002] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Exposure to the house dust mite Blomia tropicalis is increasingly being implicated as a major risk factor for asthma exacerbations in sensitized individuals. The objective of this study is to clone and characterize B. Tropicalis allergens in order to better define their role in allergic asthma. METHODS A lambda gt22A cDNA library was constructed from B. Tropicalis mRNA and screened using specific DNA probes. A full-length cDNA (Bt2-3) was isolated, subcloned, and sequenced. RESULTS Sequence analysis showed that clone Bt2-3 encodes the full-length serine protease preproenzyme from B. Tropicalis. The predicted Bt2-3 protein consists of a 15-amino-acid signal peptide, a 20-amino-acid propeptide and a mature protein of 231 amino residues. BLAST analysis of the deduced amino acid sequence showed high homology (48-54%) between clone Bt2-3 and serine proteases (group 3 allergens) from domestic dust mites. Both the serine active site (DACQGDSGGPVA; amino acids 214-225) and the histidine active site (LTAAHC; amino acids 71-76) of serine proteases were highly conserved. The estimated molecular weight of the preproenzyme is 27.5 kD and its theoretical pI is 8.7. The mature protein contains a putative tyrosine kinase phosphorylation site (amino acids 24-31) and several N-myristoylation sites. Sequence alignment shows that the serine protease active sites are highly conserved among the clinically important mite species, including B. Tropicalis. CONCLUSION We report the cloning and molecular characterization of a B. Tropicalis cDNA clone encoding a trypsin-like protease, with a possible major role as an allergen. Expression and further characterization of the recombinant product will help determine the role of proteolytic enzymes in the pathophysiology of allergic asthma.
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Affiliation(s)
- Idhaliz Flores
- Department of Microbiology, Ponce School of Medicine, Ponce, Puerto Rico
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Labrada M, Uyema K, Sewer M, Labrada A, González M, Caraballo L, Puerta L. Monoclonal antibodies against Blo t 13, a recombinant allergen from Blomia tropicalis. Int Arch Allergy Immunol 2002; 129:212-8. [PMID: 12444318 DOI: 10.1159/000066775] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The recombinant allergen of Blomia tropicalis, rBlo t 13, shows 11% of IgE reactivity to sera from allergic patients. This allergen belongs to the fatty acid-binding protein family and its natural equivalent remains to be isolated. Monoclonal antibodies (MAbs) are important tools for specific determination and isolation of natural allergens as well as for characterization of recombinant proteins. METHODS Mice were immunized with partially purified preparation of rBlo t 13 allergen expressed in the yeast Pichia pastoris. Spleen cells were fused with myeloma cells using polyethylene glycol. Hybridoma screening was performed using a direct ELISA with recombinant allergen. MAb specificity to rBlo t 13 was tested by immunoblotting. Topography of binding sites and binding of MAb to native allergen was studied by ELISA. Reactivity of MAb against allergenic extract of B. tropicalis and Dermatophagoides siboney was analyzed by ELISA inhibition. In addition, the reactivity of MAbs against rBlot 13 from Escherichia coli and P. pastoris expression was compared. RESULTS Two MAbs, 5G3 and 3G4 with IgG1 isotype, were generated. These MAbs specifically recognized the 16-kD band, which corresponds to the molecular weight shown by rBlo t 13 on SDS-PAGE. In ELISA, the binding of 5G3 MAb to B. tropicalis and D. siboney extracts was inhibited by rBlo t 13. Both MAbs showed the highest reactivity when the allergen was expressed in P. pastoris. CONCLUSION Two MAbs specific for Blo t 13 were obtained. These MAbs recognized the same or close epitopes on the rBlo t 13 molecule. The occurrence of homologous allergens to Blo t 13 in D. siboney is suggested by the ELISA inhibition assay.
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Affiliation(s)
- Mayrel Labrada
- Department of Allergens, National Center of Bioproducts (BIOCEN), Havana, Cuba
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21
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Sato MN, Oliveira CR, Futata EA, Victor JR, Maciel M, Fusaro AE, Carvalho AF, Duarte AJS. Oral tolerance induction to Dermatophagoides pteronyssinus and Blomia tropicalis in sensitized mice: occurrence of natural autoantibodies to immunoglobulin E. Clin Exp Allergy 2002; 32:1667-74. [PMID: 12569990 DOI: 10.1046/j.1365-2222.2002.01429.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The dust mites Dermatophagoides pteronyssinus (Dp) and Blomia tropicalis (Bt) are important sources of indoor allergens in tropical and subtropical countries. Murine models allow the analysis of the immune response and regulation of IgE production to Dp and Bt allergens. Oral tolerance induces unresponsiveness in naive animals, but its application in sensitized animals can provide useful information to improve allergy therapy. OBJECTIVE To study the profile of IgE and IgG subclasses antibody upon oral administration with Bt and Dp extract in previously sensitized mice. Further, the occurrence of autoantibodies IgG anti-IgE in the immunization and in the oral tolerance was investigated. METHODS A/Sn mice were immunized with Bt or Dp extract in alum, orally administrated with 0.25 mg of Bt or Dp extract or PBS at the 6th, 7th and 8th days after immunization and boosted twice with their respective allergens. To analyse the mice groups, specific IgE antibodies were measured by passive anaphylaxis reaction and specific IgG subclasses and anti-IgE IgG autoantibody by ELISA assay. RESULTS IgE levels were markedly increased in Bt-immunized mice compared with Dp-immunized mice. A distinct profile of the specific isotypes was verified in Bt-immunized mice with a preferential production of IgG3 and IgA antibodies, whereas Dp-immunized mice developed high titres of anti-Dp IgG1, IgG2a and IgG2b antibodies. The antigen feeding inhibited IgE response in both fed-mice groups but only Dp-fed mice presented decreased levels of IgG antibodies. Free anti-IgE IgG autoantibodies were detected mainly in the Dp-immunization and they correlated with the antibody isotypes found against the allergen. CONCLUSIONS This is the first time that the murine-type I hypersensitivity is employed to study Bt-immunization, showing a marked IgE production, associated with IgG response, which is at least in part driven by T-independent antigens. The oral tolerance protocol in previously sensitized animals was able to down-modulate IgE response and points out this route as a strategy for allergy therapy.
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Affiliation(s)
- M N Sato
- Laboratory of Allergy and Clinical and Experimental Immunology, School of Medicine of São Paulo, São Paulo, Brazil.
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Kennedy MW, Heikema AP, Cooper A, Bjorkman PJ, Sanchez LM. Hydrophobic ligand binding by Zn-alpha 2-glycoprotein, a soluble fat-depleting factor related to major histocompatibility complex proteins. J Biol Chem 2001; 276:35008-13. [PMID: 11425849 DOI: 10.1074/jbc.c100301200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Zn-alpha(2)-glycoprotein (ZAG) is a member of the major histocompatibility complex (MHC) class I family of proteins and is identical in amino acid sequence to a tumor-derived lipid-mobilizing factor associated with cachexia in cancer patients. ZAG is present in plasma and other body fluids, and its natural function, like leptin's, probably lies in lipid store homeostasis. X-ray crystallography has revealed an open groove between the helices of ZAG's alpha(1) and alpha(2) domains, containing an unidentified small ligand in a position similar to that of peptides in MHC proteins (Sanchez, L. M., Chirino, A. J., and Bjorkman, P. J. (1999) Science 283, 1914-1919). Here we show, using serum-derived and bacterial recombinant protein, that ZAG binds the fluorophore-tagged fatty acid 11-(dansylamino)undecanoic acid (DAUDA) and, by competition, natural fatty acids such as arachidonic, linolenic, eicosapentaenoic, and docosahexaenoic acids. Other MHC class I-related proteins (FcRn, HFE, HLA-Cw*0702) showed no such evidence of binding. Fluorescence and isothermal calorimetry analysis showed that ZAG binds DAUDA with K(d) in the micromolar range, and differential scanning calorimetry showed that ligand binding increases the thermal stability of the protein. Addition of fatty acids to ZAG alters its intrinsic (tryptophan) fluorescence emission spectrum, providing a strong indication that ligand binds in the expected position close to a cluster of exposed tryptophan side chains in the groove. This study therefore shows that ZAG binds small hydrophobic ligands, that the natural ligand may be a polyunsaturated fatty acid, and provides a fluorescence-based method for investigating ZAG-ligand interactions.
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Affiliation(s)
- M W Kennedy
- Division of Environmental and Evolutionary Biology, Institute of Biomedical and Life Sciences and the Department of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
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Liaw SH, Chen HZ, Liu GG, Chua KY. Acid-induced polymerization of the group 5 mite allergen from Dermatophagoides pteronyssinus. Biochem Biophys Res Commun 2001; 285:308-12. [PMID: 11444843 DOI: 10.1006/bbrc.2001.5184] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
House dust mites are the most important source of indoor allergens and cause allergic diseases. Our studies here suggest that the group 5 allergen from Dermatophagoides pteronyssinus (Der p 5) is monomeric at neutral pH, but forms filaments at low pH. Circular dichroism measurements show Der p 5 is a helical protein, and the protein sequence reveals Der p 5 contains coiled-coil helices. The acid-induced filament assembly could be explained in part by the high content of charged residues (40%) in the coiled-coil structure. Interestingly, some of the known Dermatophagoides allergens also contain a heptad repeat, which could potentially form coiled coils. Therefore, coiled-coil helices may be one of the common structural motifs of mite allergens that contribute to their allergenicity.
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Affiliation(s)
- S H Liaw
- Department of Life Science, National Yang-Ming University, 155 Li-Nong Street, Sec. 2, Taipei, Taiwan.
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Abstract
Interest in the nematode polyprotein allergens/antigens (NPAs) originally arose because they were often found to be immunodominant antigens of nematode parasites, and in some cases also potent allergens. Quite separately, they attracted attention as the 'ladder' proteins found close to the surface of filarial nematodes. Screening of cDNA expression libraries with antibody from infected humans or domestic animals continues to reveal more NPAs. The search for the biochemical function(s) of NPAs was originally hampered by the lack of amino acid sequence similarities between NPAs and proteins of known function, but much is now known about their biochemical activity, the highly unusual means of their biosynthesis and their gene structure. Here, Malcolm Kennedy provides an update on these intriguing proteins.
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Affiliation(s)
- M W Kennedy
- Division of Infection and Immunity, Institute of Biomedical and Life Sciences, Joseph Black Building, University of Glasgow, Glasgow, UK
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