Identification of polcalcin as a novel allergen of Amaranthus retroflexus pollen
Main Article Content
Keywords
Allergen characterization, Amaranthus retroflexus, Cloning, Polcalcin
Abstract
Introduction: Amaranthus retroflexus (Redroot Pigweed) is one of the main sources of allergenic pollens in temperate areas. Polcalcin is a well-known panallergen involved in cross-reactivity between different plants. The aim of this study was the molecular cloning and expression of polcalcin, as well as evaluating its IgE-reactivity with A. retroflexus sensitive patients’ sera.
Methods: Allergenic extract was prepared from A. retroflexus pollen and the IgE-reactivity profile was determined by ELISA and immunoblotting using sera from twenty A. retroflexus sensitive patients. Polcalcin-coding sequence was amplified by conventional PCR method and the product was inserted into pET-21b(+) vector. The recombinant protein was expressed in E. coli BL21 and purified by metal affinity chromatography. The IgE-binding capability of the recombinant protein was analyzed by ELISA and immunoblotting assays, and compared with crude extract.
Results: Of 20 skin prick test-positive patients, 17 patients were positive in IgE-specific ELISA. Western blotting confirmed that approximately 53% of ELISA positive patients reacted with 10 kDa protein in crude extract. The A. retroflexus polcalcin gene, encoding to 80 amino acid residues was cloned and expressed as a soluble protein and designated as Ama r 3. The recombinant polcalcin showed rather identical IgE-reactivity in ELISA and western blotting with 10 kDa protein in crude extract. These results were confirmed by inhibition methods, too.
Conclusion: The recombinant form of A. retroflexus polcalcin (Ama r 3) could be easily produced in E. coli in a soluble form and shows rather similar IgE-reactivity with its natural counterpart.
References
2. Vaquero C, Rodríguez-Torres A, Rojo J, Pérez-Badia R. Airborne pollen of allergenic herb species in Toledo (Spain). Environ Monit Assess. 2013;185:335-46.
3. Ezeamuzie C, Thomson M, Al-li S, Dowaisan A, Khan M, Hijazi Z. Asthma in the desert: spectrum of the sensitizing aeroallergens. Allergy. 2000;55:157-62.
4. Carinanos ˜ P, Alcázar P, Galán C, Domínguez E. Environmental behaviour of airborne Amaranthaceae pollen in the southern part of the Iberian Peninsula, and its role in future climate scenarios. Sci Total Environ. 2014;470:480-7.
5. Villalba M, Barderas R, Mas S, Colás S, Batanero E, Rodríguez García R. Amaranthaceae pollens: review of an emerging allergy in the mediterranean area. J Invest Allergol Clin Immunol. 2014;24:288-97.
6. Fereidouni M, Hossini RF, Azad FJ, Assarezadegan MA, Varasteh A. Skin prick test reactivity to common aeroallergens among allergic rhinitis patients in Iran. Allergol Immunopathol. 2009;37:73-9.
7. Tehrani M, Sankian M, Assarehzadegan MA, Falak R, Jabbari F, Varasteh A. Immunochemical characterization of Amaranthus retroflexus pollen extract: extensive cross-reactive allergenic components among the four species of Amaranthaceae/Chenopodiaceae. Iran J Allergy Asthma Immunol. 2010;9:87.
8. Wurtzen P, Nelson H, Løwenstein H, Ipsen H. Characterization of Chenopodiales (Amaranthus retroflexus, Chenopodium album, Kochia scoparia, Salsola pestifer) pollen allergens. Allergy. 1995;50:489-97.
9. Morakabati P, Assarehzadegan M-A, Khosravi GR, Akbari B, Dousti F. Cloning and expression of Ama r 1, as a novel allergen of Amaranthus retroflexus pollen. J Allergy. 2016:2016.
10. Tehrani M, Sankian M, Assarehzadegan MA, Falak R, Noorbakhsh R, Moghadam M, et al. Identification of a new allergen from Amaranthus retroflexus pollen Ama r 2. Allergol Int. 2011;60:309-16.
11. Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976;72:248-54.
12. Chomczynski P, Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem. 1987;162:156-9.
13. Barderas R, Villalba M, Pascual CY, Batanero E, Rodríguez R. Profilin (Che a 2) and polcalcin (Che a 3) are relevant allergens of Chenopodium album pollen: isolation, amino acid sequences, and immunologic properties. J Allergy Clin Immunol. 2004;113:1192-8.
14. Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970;227:680-5.
15. Galán C, Infante F, Ruiz de Clavijo E, Guerra F, Miguel R, Domínguez E. Allergy to pollen grains from Amaranthaceae and Chenopodiaceae in Cordoba Spain. Annual and daily variation of pollen concentration. Ann Allergy. 1989;63:435-8.
16. Valenta R, Hayek B, Seiberler S, Bugajska-Schretter A, Niederberger V, Twardosz A, et al. Calcium---binding allergens: from plants to man. Int Arch Allergy Immunol. 1998;117:160-6.
17. Seiberler S, Scheiner O, Kraft D, Lonsdale D, Valenta R. Characterization of a birch pollen allergen Bet v III, representing a novel class of Ca2+ binding proteins: specific expression in mature pollen and dependence of patients’ IgE binding on protein-bound Ca2+. EMBO J. 1994;13:3481.
18. Engel E, Richter K, Obermeyer G, Briza P, Kungl AJ, Simon B, et al. Immunological and biological properties of Bet v 4, a novel birch pollen allergen with two EF-hand calcium-binding domains. J Biol Chem. 1997;272:28630-7.
19. Twardosz A, Hayek B, Seiberler S, Vangelista L, Elfman L, Grönlund H, et al. Molecular characterization, expression in escherichia coli, and epitope analysis of a two EF-hand calcium-binding birch pollen allergen, Bet v 4. Biochem Biophys Res Commun. 1997;239:197-204.
20. Hayek B, Vangelista L, Pastore A, Sperr WR, Valent P, Vrtala S, et al. Molecular and immunologic characterization of a highly cross-reactive two EF-hand calcium-binding alder pollen allergen Aln g 4: structural basis for calcium-modulated IgE recognition. J Immunol. 1998;161:7031-9.
21. Batanero E, Villalba M, Ledesma A, Puente XS, Rodríguez R. Ole e 3, an olive-tree allergen, belongs to a widespread family of pollen proteins. Eur J Biochem. 1996;241:772-8.
22. Suphioglu C, Ferreira F, Knox RB. Molecular cloning and immunological characterisation of Cyn d 7, a novel calcium binding allergen from Bermuda grass pollen 1. FEBS Lett. 1997;402:167-72.
23. Smith P, Xu H, Swoboda I, Singh M. Identification of a Ca2+ binding protein as a new Bermuda grass pollen allergen Cyn d 7: IgE cross reactivity with oilseed rape pollen allergen Bra r 1. Int Arch Allergy Immunol. 1997;114:265-71.
24. Niederberger V, Hayek B, Vrtala S, Laffer S, Twardosz A, Vangelista L, et al. Calcium-dependent immunoglobulin E recognition of the apo-and calcium-bound form of a cross-reactive two EF-hand timothy grass pollen allergen Phl p 7. FASEB J. 1999;13:843-56.
25. Toriyama K, Okada T, Watanabe M, Ide T, Ashida T, Xu H, et al. A cDNA clone encoding an IgE-binding protein from Brassica
anther has significant sequence similarity to Ca2+-binding proteins. Plant Mol Biol. 1995;29:1157-65.
