Polymorphism of Aspergillus Fumigatus Major Allergen Genes Associating with Their Isolated Sites Affects Their IgE Epitope Structures

The circumstances in which organisms live induce polymorphism in their genes, including fungal allergen genes, leading to altered structures and functions of proteins, related to their pathogenicity. Major allergen genes of Aspergillus fumigatus, Asp f 1, Asp f 2, and Asp f 3, were examined in 59 strains [environment and animal/human-body origin] to determine their nucleotide sequences, and then categorized. The location and number of IgE epitopes on the allergen molecules were predicted using a computer software. The Asp f 1 gene was classified into two groups (f1-1 and f1-2). One of the groups possessed one-nucleotide mutation point with one amino-acid substitution. The mutated Asp f 2 gene accompanying 6-amino acid substitution was classified into 7 groups (f2-1 to f2-7). Six of the groups possessed a newborn IgE epitope. The Asp f 3 gene contained two mutations, resulted in three groups (f3-1 to f3-3) without any amino-acid substitutions. Category E, consisting of groups f1-1, f2-5, and f3-2, was specific to an environmental origin. Our findings suggest that nucleotide mutation of the fungal allergen genes, associated with the origin of the fungus, modifies the structure of proteins, and affects their pathogenic properties, such as the localization of IgE epitopes.

Molecular allergen sensitization of Aspergillus fumigatus in allergic bronchopulmonary aspergillosis in Guangzhou, Southern China

Background Few studies have assessed the sensitization of mycotic allergens and Aspergillus fumigatus molecular allergen. This study aimed to investigate the connection between A.fumigatus components and mycotic allergens between allergic bronchopulmonary aspergillosis (ABPA) patients and A. fumigatus (Af)-sensitized asthma. Methods Serum Penicillium chrysogenum , Cladosporium herbarum , Mucor racemosus , Candida albicans , Alternaria alternata , Helminthosporium halodes and A.fumigatus allergen components (Asp f 1, Asp f 2, Asp f 3, Asp f 4, and Asp f 6) sIgE level were measured via ImmunoCAP assay in 18 ABPA patients and 54 Af-sensitized asthma patients in Guangzhou city. Results 94.44% of ABPA patients and 87.04% of Af-sensitized asthma patients were co-sensitization to at least one another fungal allergen. The positivity rates of C. albicans ( P < 0.05) and A.alternata ( P < 0.05) were higher in ABPA than that in Af-sensitized asthma patients. The positive rates of Asp f 1 (88.89% vs 59.26%, P < 0.05), Asp f 2 (66.67% vs 33.33%, P < 0.05), Asp f 4 (61.11% vs 33.33%, P < 0.05), and Asp f 6 (66.67% vs 14.81%, P < 0.001) in ABPA were higher than those in Af-sensitized asthma patients. Patients with ABPA had higher IgE levels of Asp f 1 ( P < 0.05), Asp f 4 ( P < 0.05) and Asp f 6 ( P < 0.001) than those of Af-sensitized asthma patients. A.fumigatus was strongly correlated with C.herbarum ( r s = 0.688) in ABPA and A.alternata ( r s = 0.692) in Af-sensitized asthma patients. Optimal scale analysis was show that ABPA was more relevant to Af-components. (Cronbach`s alpha = 90.7%) Conclusion The A.fumigatus components and it`s connection with various mycotic allergens were different in ABPA and Af-sensitized asthma patients. This findings can expected to help local doctors in the diagnosis and immunotherapy of fungal allergies.

Indoor Exposure to Mould Allergens

Indoor Exposure to Mould AllergensHumid indoor environments may be colonised by allergenic filamentous microfungi (moulds),Aspergillusspp.,Penicilliumspp.,Cladosporiumspp., andAlternariaspp. in particular. Mould-induced respiratory diseases are a worldwide problem. In the last two decades, mould allergens and glucans have been used as markers of indoor exposure to moulds. Recently, mould allergens Alt a 1 (Alternaria alternata) and Asp f 1 (Aspergillus fumigatus) have been analysed in various environments (residential and occupational) with enzyme-linked immunosorbent assays, which use monoclonal or polyclonal antibodies. Household Alt a 1 and Asp f 1 levels were usually under the limit of the method detection. By contrast, higher levels of mould allergens were found in environments with high levels of bioaerosols such as poultry farms and sawmills. Data on allergen Alt a 1 and Asp f 1 levels in agricultural settings may provide information on possible colonisation of respective moulds and point out to mould-related diseases in occupants.

Determination of Aspergillus Fumigatus Allergen 1 in Poultry Farms Using the Enzyme Immunoassay

Determination ofAspergillus FumigatusAllergen 1 in Poultry Farms Using the Enzyme ImmunoassayPoultry farms contain high levels of allergenic fungi, andAspergillusspp. is the most common genus of moulds.Aspergillus fumigatusantigens are responsible for the development of several respiratory diseases including asthma. The aim of this study was to measure the mass fraction of Asp f 1, a major allergen ofAsperillus fumigatusin 37 indoor dust samples collected from four poultry farms in a rural area of the Zagreb County (Croatia) using the enzyme-linked immunosorbent assay. More than 62 % of dust samples had detectable Asp f 1 levels (limit of detection 3.6 ng g-1). The overall mean Asp f 1 level was 17.9 ng g-1[range (3.8 to 72.4) ng g-1]. Satisfactory results were obtained for analytical within-run imprecision (6.7 %), between-run imprecision (10.5 %), and accuracy (91 % to 115 %). Microclimate parameters (air temperature, relative humidity, and velocity) were within the recommended ranges in all poultry farms. This study has shown that Asp f 1 settles on dust at poultry farms and that occupational exposure to this allergen deserves monitoring in livestock buildings.