title: IgE-binding epitope analysis of Bla g 5, the German cockroach allergen.
abstract: Cockroach infestations have been linked with allergic diseases such as asthma in humans. Bla g 5, sigma class glutathione S-transferase (GST), is the major cockroach allergen which has the highest IgE response value of all cockroach allergens. Although several cockroach allergens have been identified and cloned, information regarding their B ell and T cell IgE-binding epitopes is limited. In order to analyze the IgE binding epitopes of Bla g 5, full-length and five peptide fragments (A, 1-100 amino acid residue; B, 91-200; Ba, 1-125; Bb, 1-150; Bc, 1-175) were expressed. Twelve (37.5%) of 32 sera from cockroach-sensitized subjects showed positive IgE reactivity to the recombinant Bla g 5 (rBla g 5). Six strong positive sera were selected for the epitope study. Recombinant proteins not containing 176-200 amino acid residues were unable to react to sera from cockroach sensitized individuals, suggesting that this region contains the IgE-binding epitope. Despite strong IgE reactivity to rBla g 5, the pooled serum from 5 cockroach-sensitized patients did not show IgE reactivity to all synthetic peptides consisting of 15 residues covering 161-200 amino acids. These results suggest the possibility that Bla g 5 may have a conformational epitope in the C-terminal region. GST is the important target for the development of vaccines and drugs against allergic diseases because of high cross-reactivity among insect species. This study will aid recombinant allergen research for immunotherapy of cockroach allergens and other insect allergens.
authors.affiliation: Department of Environmental Medical Biology and Institute of Tropical Medicine, Korea National Arthropods of Medical Importance Resource Bank, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyoung-Jin
authors.initials: KJ
authors.lastname: Jeong
authors.forename: Kyoung Yong
authors.initials: KY
authors.lastname: Jeong
authors.forename: Chung-Ryul
authors.initials: CR
authors.lastname: Kim
authors.forename: Tai-Soon
authors.initials: TS
authors.lastname: Yong
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D020048:Blattellidae / Q000235:genetics / Q000276:immunology*; D002648:Child; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs
chemical_list: D000485:Allergens; D000939:Epitopes; D019476:Insect Proteins; D010446:Peptide Fragments; D007073:Immunoglobulin E