title: Identification of italian cypress (Cupressus sempervirens) pollen allergen Cup s 3 using homology and cross-reactivity.
abstract: BACKGROUND
  The prevalence of seasonal allergic diseases of the upper airways is increasing in industrialized countries. The Cupressaceae are important causes of pollinosis, particularly in Europe.
  
  
  OBJECTIVE
  To determine whether the pollen from Cupressus sempervirens (Italian cypress) contains a pathogenesis-related group 5 (PR-5) protein, similar to that found in other allergenic Cupressaceae pollens.
  
  
  METHODS
  Messenger RNA was purified from Italian cypress pollen, and complementary DNA (cDNA) was synthesized. cDNAs for PR-5 proteins were amplified by polymerase chain reaction and extended by rapid amplification of cDNA ends methods. Recombinant Cup s 3 was expressed in Escherichia coli as a fusion protein. Inhibition enzyme-linked immunosorbent assays were used to test the allergenicity of Cup s 3.
  
  
  RESULTS
  Three cDNAs were cloned. These clones had approximately 95% identity to Jun a 3 and Cup a 3. Recombinant Cup s 3.0102 maltose-binding protein inhibited the IgE from most patients from binding to an extract of Italian cypress. The extent of inhibition suggested that antibodies to Cup s 3 were a prominent component of the IgE response to Italian cypress pollen.
  
  
  CONCLUSIONS
  Cup s 3, an allergen of Italian cypress pollen, was identified based on cross-reactivity and homology with other pollen PR-5 proteins, despite an apparently low level of protein expression. Variations in the content of Cup s 3 in the pollen from different regions or trees should be considered in the choice of extracts for diagnosis and specific immunotherapy for Italian cypress pollen hypersensitivity.
authors.affiliation: Department of Pediatrics, Child Health Research Center, University of Texas Medical Branch, Galveston 77555-0366, USA.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Togawa
authors.forename: Raphael C
authors.initials: RC
authors.lastname: Panzani
authors.forename: Maritza A
authors.initials: MA
authors.lastname: Garza
authors.forename: Reiko
authors.initials: R
authors.lastname: Kishikawa
authors.forename: Randall M
authors.initials: RM
authors.lastname: Goldblum
authors.forename: Terumi
authors.initials: T
authors.lastname: Midoro-Horiuti
mesh_terms: D000328:Adult; D000485:Allergens / Q000235:genetics* / Q000276:immunology; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D015153:Blotting, Western; D003001:Cloning, Molecular; D003429:Cross Reactions; D029781:Cupressus / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000276:immunology; D011058:Pollen / Q000235:genetics* / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D006255:Rhinitis, Allergic, Seasonal / Q000235:genetics / Q000276:immunology*
chemical_list: D000485:Allergens; D052179:Antigens, Plant; C404816:Jun a 3 protein, Juniperus ashei; D010940:Plant Proteins; D012333:RNA, Messenger