T Soongrung1, K Mongkorntanyatip1, T Peepim1, A Buaklin1, M Le Mignon2, N Malainual3, E Nony2, A Jacquet1. 1. Chula Vaccine Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. 2. Stallergenes-Greer, Antony, France. 3. Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
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.
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.
Authors: Eduardo Santos da Silva; Lorenz Aglas; Carina Silva Pinheiro; Emília M M de Andrade Belitardo; Elisânia Fontes Silveira; Sara Huber; Rogério Tanan Torres; Michael Wallner; Peter Briza; Peter Lackner; Josef Laimer; Luis Gustavo C Pacheco; Álvaro A Cruz; Neuza Maria Alcântara-Neves; Fatima Ferreira Journal: Clin Exp Allergy Date: 2020-05-13 Impact factor: 5.018
Authors: Luis Caraballo; Rudolf Valenta; Leonardo Puerta; Anna Pomés; Josefina Zakzuk; Enrique Fernandez-Caldas; Nathalie Acevedo; Mario Sanchez-Borges; Ignacio Ansotegui; Luo Zhang; Marianne van Hage; Eva Fernández; Luisa Arruda; Susanne Vrtala; Mirela Curin; Hans Gronlund; Antonina Karsonova; Jonathan Kilimajer; Ksenja Riabova; Daria Trifonova; Alexander Karaulov Journal: World Allergy Organ J Date: 2020-04-29 Impact factor: 4.084
Authors: Jarmila Čelakovská; Josef Bukač; Eva Cermákova; Radka Vaňková; Hana Skalská; Jan Krejsek; Ctirad Andrýs Journal: Int J Mol Sci Date: 2021-05-17 Impact factor: 5.923