High Environmental Ozone Levels Lead to Enhanced Allergenicity of Birch Pollen

• Published in: PloS one Vol. 8; no. 11; p. e80147
• Main Authors: Beck, Isabelle, Jochner, Susanne, Gilles, Stefanie, McIntyre, Mareike, Buters, Jeroen T. M., Schmidt-Weber, Carsten, Behrendt, Heidrun, Ring, Johannes, Menzel, Annette, Traidl-Hoffmann, Claudia
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 20.11.2013; Public Library of Science (PLoS)
• Subjects: Air Pollutants - analysis; Air pollution; Allergenicity; Allergens; Allergens - immunology; Allergies; Allergy; Anthropogenic factors; Archives & records; Betula - immunology; Birch trees; Cell migration; Climate change; Dendritic cells; Dermatology; Dinoprostone - metabolism; Ecosystems; Education; Environmental factors; Enzyme-Linked Immunosorbent Assay; Future climates; Global temperature changes; Human influences; Humans; Immunology; In vivo methods and tests; Interleukin; Interleukin 12; Interleukins; Leukocyte migration; Leukotriene B4 - metabolism; Lipid composition; Lipids; Nitrogen dioxide; Ozone; Ozone - analysis; Pollen; Pollen - immunology; Pollution monitoring; Skin; Skin Tests; Studies; Temperature; Trends; Urban areas; Urbanization; Germany
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0080147

Evidence is compelling for a positive correlation between climate change, urbanisation and prevalence of allergic sensitisation and diseases. The reason for this association is not clear to date. Some data point to a pro-allergenic effect of anthropogenic factors on susceptible individuals. To evaluate the impact of urbanisation and climate change on pollen allergenicity. Catkins were sampled from birch trees from different sites across the greater area of Munich, pollen were isolated and an urbanisation index, NO2 and ozone exposure were determined. To estimate pollen allergenicity, allergen content and pollen-associated lipid mediators were measured in aqueous pollen extracts. Immune stimulatory and modulatory capacity of pollen was assessed by neutrophil migration assays and the potential of pollen to inhibit dendritic cell interleukin-12 response. In vivo allergenicity was assessed by skin prick tests. The study revealed ozone as a prominent environmental factor influencing the allergenicity of birch pollen. Enhanced allergenicity, as assessed in skin prick tests, was mirrored by enhanced allergen content. Beyond that, ozone induced changes in lipid composition and chemotactic and immune modulatory potential of the pollen. Higher ozone-exposed pollen was characterised by less immune modulatory but higher immune stimulatory potential. It is likely that future climate change along with increasing urbanisation will lead to rising ozone concentrations in the next decades. Our study indicates that ozone is a crucial factor leading to clinically relevant enhanced allergenicity of birch pollen. Thus, with increasing temperatures and increasing ozone levels, also symptoms of pollen allergic patients may increase further.