title: Molecular and immunological approaches in quantifying the air-borne food allergen tropomyosin in crab processing facilities.
abstract: Tropomyosin is a cross-reactive allergenic protein present in ingested shellfish species. Exposure and sensitization to this protein via inhalation is particularly important in the crustacean processing industry where workers are continuously exposed to the aerosolized form of this allergen. The aim of this study was to develop an antibody-based immunoassay to enable the specific and sensitive quantification of aerosolized tropomyosin present in the environment of two crab processing facilities. Anti-tropomyosin antibody was generated in rabbits against tropomyosins from four different crustacean species. These antibodies were purified using recombinant tropomyosin using an immuno-affinity column. The recombinant tropomyosin was also used as an allergen standard for the sandwich ELISA. In order to quantify aerosolized tropomyosin, air collection was performed in the personal breathing zone of 80 workers during two crab processing activities, edible crab (Cancer pagurus) and king crab (Paralithodes camtschaticus) using polytetrafluoroethylene filters. The purified antibody was able to detect tropomyosin selectively from different crustaceans but not from vertebrate sources. The limit of detection (LOD) for the developed sandwich ELISA was 60 picogram/m(3) and limit of quantitation (LOQ) 100 picogram/m(3). Immunoassay validation was based on linearity (R(2) 0.999), matrix interference test (78.8±6.5%), intra-assay CV (9.8%) and inter-assay CV (11%). The novel immunoassay was able to successfully identify working activities, which generated low, medium or high concentrations of the aerosolized food allergen. We describe an IgG antibody-based immunoassay for quantification of the major food allergen tropomyosin, with high sensitivity and specificity. This modified immunological approach can be adapted for the detection of other aerosolized food allergens, assisting in the identification of high-risk allergen exposure areas in the food industry.
authors.affiliation: Molecular Immunology Group, School of Pharmacy and Molecular Science, James Cook University, Townsville, QLD, Australia; Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Townsville, QLD, Australia. Electronic address: sandip.kamath@jcu.edu.au.
authors.forename: Sandip D
authors.initials: SD
authors.lastname: Kamath
authors.affiliation: Department of Occupational- and Environmental Medicine, University Hospital of North Norway, Tromsø, Norway; Department of Community Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway. Electronic address: marte.renate.thomassen@unn.no.
authors.forename: Marte R
authors.initials: MR
authors.lastname: Thomassen
authors.affiliation: Molecular Immunology Group, School of Pharmacy and Molecular Science, James Cook University, Townsville, QLD, Australia; Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Townsville, QLD, Australia. Electronic address: Shruti.saptarshi@jcu.edu.au.
authors.forename: Shruti R
authors.initials: SR
authors.lastname: Saptarshi
authors.affiliation: Faculty of Food Science and Technology, Nong Lam University, Ho Chi Minh City, Viet Nam. Electronic address: nmxuanhong@yahoo.com.
authors.forename: Hong M X
authors.initials: HM
authors.lastname: Nguyen
authors.affiliation: Department of Occupational- and Environmental Medicine, University Hospital of North Norway, Tromsø, Norway; Medical Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway. Electronic address: lisbeth.aasmoe@unn.no.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Aasmoe
authors.affiliation: Department of Occupational- and Environmental Medicine, University Hospital of North Norway, Tromsø, Norway; Medical Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway. Electronic address: berit.bang@unn.no.
authors.forename: Berit E
authors.initials: BE
authors.lastname: Bang
authors.affiliation: Molecular Immunology Group, School of Pharmacy and Molecular Science, James Cook University, Townsville, QLD, Australia; Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Townsville, QLD, Australia. Electronic address: andreas.lopata@jcu.edu.au.
authors.forename: Andreas L
authors.initials: AL
authors.lastname: Lopata
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D000485:Allergens / Q000032:analysis*; D000595:Amino Acid Sequence; D000818:Animals; D003386:Brachyura / Q000276:immunology*; D003429:Cross Reactions; D004784:Environmental Monitoring / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005512:Food Hypersensitivity; D005525:Food-Processing Industry; D006801:Humans; D008969:Molecular Sequence Data; D016273:Occupational Exposure / Q000032:analysis; D016415:Sequence Alignment; D012758:Shellfish; D014335:Tropomyosin / Q000032:analysis* / Q000737:chemistry
chemical_list: D000395:Air Pollutants, Occupational; D000485:Allergens; D014335:Tropomyosin
keywords: Airborne allergen; Allergen detection; Occupational allergy; Sandwich ELISA; Shellfish; Tropomyosin