title: Specific B-cell Epitope of Per a 1: A Major Allergen of American Cockroach (Periplaneta americana) and Anatomical Localization.
abstract: OBJECTIVE
  Cockroach (CR) is a common source of indoor allergens, and Per a 1 is a major American CR (Periplaneta americana) allergen; however, several attributes of this protein remain unknown. This study identifies a novel specific B cell epitope and anatomical locations of Per a 1.0105.
  
  
  METHODS
  Recombinant Per a 1.0105 (rPer a 1.0105) was used as BALB/c mouse immunogen for the production of monoclonal antibodies (MAb). The MAb specific B cell epitope was identified by determining phage mimotopic peptides and pair-wise alignment of the peptides with the rPer a 1.0105 amino acid sequence. Locations of the Per a 1.0105 in P. americana were investigated by immunohistochemical staining.
  
  
  RESULTS
  The rPer a 1.0105 (~13 kDa) had 100%, 98% and ≥90% identity to Per a 1.0105, Per a 1.0101, and Cr-PII, respectively. The B-cell epitope of the Per a 1.0105 specific-MAb was located at residues(99) QDLLLQLRDKGV(110) contained in all 5 Per a 1.01 isoforms and Per a 1.02. The epitope was analogous to the Bla g 1.02 epitope; however, this B-cell epitope was not an IgE inducer. Per a 1.0105 was found in the midgut and intestinal content of American CR but not in the other organs. The amount of the Per a 1 was ~544 ℃g per gram of feces.
  
  
  CONCLUSIONS
  The novel Per a 1 B-cell epitope described in this study is a useful target for allergen quantification in samples; however, the specific MAb can be used as an allergen detection reagent. The MAb based-affinity resin can be made for allergen purification, and the so-purified protein can serve as a standard and diagnostic allergen as well as a therapeutic vaccine component. The finding that the Per a 1 is contained in the midgut and feces is useful to increase yield and purity when preparing this allergen.
authors.affiliation: Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Nitat
authors.initials: N
authors.lastname: Sookrung
authors.affiliation: Graduate Program in Microbiology, Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Thanyathon
authors.initials: T
authors.lastname: Khetsuphan
authors.affiliation: Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailandand.
authors.forename: Urai
authors.initials: U
authors.lastname: Chaisri
authors.affiliation: Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailandand.
authors.forename: Nitaya
authors.initials: N
authors.lastname: Indrawattana
authors.affiliation: Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailandand.
authors.forename: Onrapak
authors.initials: O
authors.lastname: Reamtong
authors.affiliation: Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Wanpen
authors.initials: W
authors.lastname: Chaicumpa
authors.affiliation: Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Anchalee
authors.initials: A
authors.lastname: Tungtrongchitr
keywords: American cockroach; B-cell epitope; Per a 1; Periplaneta americana, mimotope; hybridoma