title: Molecular Cloning and Expression of a New Allergen of Acacia farnesiana (Aca f 2).
abstract: Inhalation of pollens from different species of Acacia is a common cause of respiratory allergy in tropical areas of the world. Acacia farnesiana is commonly used as street trees in towns and ornamental shade trees in parks and gardens throughout arid and semi-arid regions of Asia. This study aimed to produce and purify the A. farnesiana pollen profilin (Aca f 2) and evaluate its nucleotide sequence homology with profilins of common allergenic plants to predict allergenic cross-reactivity. Thirty-nine patients who were allergic to Acacia pollens were included in the study. Cloning of Acacia profilin-coding sequence was performed by polymerase chain reaction using primers from Acacia pollen RNA. The cDNA of Acacia pollen profilin was then expressed in Escherichia coli using pET-21b(+) vector and puriﬁed by metal affinity chromatography. Immunoreactivity of the recombinant Acacia profilin (rAca f 2) was evaluated by specific ELISA, immunoblotting, and inhibition assays. The coding sequence of the Acacia profilin cDNA was recognized as a 399-bp open reading frame encoding 133 amino acid residues. Eighteen patients (18/39, 46.15%) had significant specific IgE levels against Aca f 2. Immunodetection and inhibition assays indicated that puriﬁed Aca f 2 might be the same as that in the crude extract. Aca f2, the first allergen from A. farnesiana pollen, was identified as belonging to the family of profilins. The amino acid sequence homology analysis showed high cross-reactivity between Aca f 2 and other profilins from botanically unrelated common allergenic plants.
authors.affiliation: Department of Immunology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Najmeh
authors.initials: N
authors.lastname: Sepahi
authors.affiliation: Department of Immunology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Khodadadi
authors.affiliation: Department of Immunology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Mohammad-Ali
authors.initials: MA
authors.lastname: Assarehzadegan
authors.affiliation: Department of Immunology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Akram
authors.initials: A
authors.lastname: Amini
authors.affiliation: Department of Immunology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Farnoosh
authors.initials: F
authors.lastname: Zarinhadideh
authors.affiliation: Department of Immunology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Hosein
authors.initials: H
authors.lastname: Ali-Sadeghi
mesh_terms: D000045:Acacia / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003429:Cross Reactions; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000276:immunology
chemical_list: D000485:Allergens; D011994:Recombinant Proteins; D007073:Immunoglobulin E
keywords: Acacia; Cloning; Cross Reaction; Expression; Profilin