title: Vacuolar Serine Protease Is a Major Allergen of Fusarium proliferatum and an IgE-Cross Reactive Pan-Fungal Allergen.
abstract: OBJECTIVE
  Fusarium species are among prevalent airborne fungi and causative agents of human respiratory atopic disorders. We previously identified a 36.5-kDa F. proliferatum component recognized by IgE antibodies in 9 (53%) of the 17 F. proliferatum-sensitized atopic serum samples. The purpose of this study is to characterize the 36.5-kDa allergen of F. proliferatum.
  
  
  METHODS
  Characterization of allergens and determination of IgE cross-reactivity were performed by cDNA cloning/expression and immunoblot inhibition studies.
  
  
  RESULTS
  Based on the finding that the 36.5-kDa IgE-binding component reacted with the mouse monoclonal antibody FUM20 against fungal vacuolar serine protease allergens, the cDNA of F. proliferatum vacuolar serine protease (Fus p 9.0101) was subsequently cloned. Nine serum samples from respiratory atopic patients with IgE binding to the vacuolar serine protease allergen of Penicillium chrysogenum (Pen ch 18) also showed IgE-immunoblot reactivity to rFus p 9.0101. The purified rFus p 9.0101 can inhibit IgE and FUM20 binding to the 36.5-kDa component of F. proliferatum. Thus, a novel and important Fus p 9.0101 was identified. The rPen ch 18 can inhibit IgE binding to Fus p 9.0101. It indicates that IgE cross-reactivity between Fus p 9.0101 and Pen ch 18 also exists. Furthermore, neither rFus p 9.0101 K88A nor rPen ch 18 K89A mutants inhibited IgE binding to rFus p 9.0101. Lys88 was considered a critical core amino acid in IgE binding to r Fus p 9.0101 and a residue responsible for IgE cross-reactivity between Fus p 9.0101 and Pen ch 18 allergens.
  
  
  CONCLUSIONS
  Results obtained from this study indicate that vacuolar serine protease may be a major allergen of F. proliferatum and an important IgE cross-reactive pan-fungal allergen, and provide important bases for clinical diagnosis of fungal allergy.
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital and Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan, R.O.C.
authors.forename: Chang Ching
authors.initials: CC
authors.lastname: Yeh
authors.affiliation: Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C.
authors.forename: Hsiao Yun
authors.initials: HY
authors.lastname: Tai
authors.affiliation: Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C.
authors.forename: Hong
authors.initials: H
authors.lastname: Chou
authors.affiliation: Department of Pediatrics, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan, R.O.C.
authors.forename: Keh Gong
authors.initials: KG
authors.lastname: Wu
authors.affiliation: Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C. hdshen@vghtpe.gov.tw.
authors.forename: Horng Der
authors.initials: HD
authors.lastname: Shen
keywords: F. proliferatum; IgE cross-reactivity; allergen; vacuolar serine protease