Increasing allergy potency of Zinnia pollen grains in polluted areas

Background: Epidemiologic studies reveal a dramatic increase in allergies in the last decades. Air pollution is considered to be one of the factors responsible for this augmentation. The aim of this study was to analyze the impact of urbanization on birch pollen. The birch pollen proteome was investigated in order to identify differences in protein abundance between pollen from rural and urban areas. The allergenicity of birch pollen from both areas was evaluated by assessing its chemotactic potency as well as its protein and allergen contents. Methods: Difference gel electrophoresis (DIGE) was used to analyze the pollen proteome. The chemotactic activity of aqueous pollen extracts was determined by migration assays of human neutrophils. Results: DIGE revealed 26 differences in protein spot intensity between pollen from urban and rural areas. One of these proteins was identified by de novo sequencing as the 14-3-3 protein, which resembles a stress-induced factor in other plant species. Furthermore, extracts from pollen collected in urban areas had higher chemotactic activity on human neutrophils compared to pollen from rural sites. Conclusions: The present study points to an impact of air pollution on allergen carrier proteome and release of chemotactic substances. The increment in proinflammatory substances such as pollen-associated lipid mediators might contribute to the described urban-rural gradient of allergy prevalence. Furthermore, our study suggests that allergenicity is determined by more than the sole allergen content.

Section: Discussionmentioning

confidence: 73%

Impact of Urbanization on the Proteome of Birch Pollen and Its Chemotactic Activity on Human Granulocytes

Bryce¹,

Drews

Schenk

et al. 2009

“…Protein and allergen losses due to urban pollution exposure or to gaseous experimental exposure to high concentrations of pollutants were previously described [18, 19, 25]. However, in our experiments, we used lower pollutant concentrations than those used by the former authors, inducing few damages on pollen grains and a weak intra-cytoplasmic granule release [20].…”

Section: Discussionmentioning

confidence: 99%

“…They have also been shown to trigger primary and secondary allergic responses in pollen-sensitised Brown Norway rats [23, 24]. Recently, Zinnia pollen exposed to polluted air has been shown to trigger higher allergic responses in guinea pig [18]. …”

Section: Introductionmentioning

confidence: 99%

“…Pollen that had been collected at road sides showed significantly reduced allergen release in comparison with pollen collected in rural meadows [17]. Moreover, morphological modifications were reported in pollen shape and tectum under polluted conditions [18, 19]. Pollen grains collected from polluted areas were covered with large amounts of pollutants such as airborne particles, heavy metals, nitrate and sulphur [16].…”

Section: Introductionmentioning

confidence: 99%

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Modifications of Phleum pratense Grass Pollen Allergens following Artificial Exposure to Gaseous Air Pollutants (O3, NO2, SO2)

Rogerieux

Godfrin²,

Sénéchal³

et al. 2007

Background: Air pollution is frequently proposed as a potential cause of the increased incidence of allergy in industrialised countries. Our objective was to investigate the impact of the major gaseous air pollutants on grass pollen allergens. Methods: Timothy grass pollen was exposed to ozone (O₃), nitrogen dioxide (NO₂) and sulphur dioxide (SO₂) alone or in combination. Allergen contents were analysed by 2-dimensional immunoblot using grass pollen-sensitive patient sera. Results: For O₃-treated pollen, immunoblotting showed an acidification of allergens Phl p 1b, Phl p 4, Phl p 5 and Phl p 6 and an IgE recognition decrease in Phl p 1, Phl p 2, Phl p 6 and Phl p 13. NO₂ exposure induced a decrease in Phl p 2, Phl p 5b and Phl p 6 recognition, and SO₂ treatment induced a decrease in Phl p 2, Phl p 6 and Phl p 13 recognition. Moreover, samples treated with a mix of NO₂/O₃ or NO₂/SO₂ showed a higher decrease in allergen content, compared with samples treated with only one pollutant. The O₃ acidification was also observed with the NO₂/O₃ mix. Conclusion: Exposure of pollen to gaseous pollutants induced a decrease in allergen detection in pollen extracts. This decrease could be due to a mechanical loss of allergens from the altered pollen grains and/or post-translational modifications affecting allergen recognition by IgE.

“…The traffic-related gaseous pollutants O 3 and NO 2 are known for their toxicity on respiratory tracts, as well as for their adjuvant effect on respiratory hypersensitivity and on asthma [1,2,3,4,5]. Moreover, these pollutants can also interact with airborne pollen grains and modify their allergen content and release [6, 7]. Phleum pratense pollen is one of the most common sources of outdoor allergens.…”

Section: Introductionmentioning

confidence: 99%

Traffic-Related Air Pollutants Induce the Release of Allergen-Containing Cytoplasmic Granules from Grass Pollen

Motta

Marliere

Peltre³

et al. 2006

146

Background/Aim: Pollen cytoplasmic granules (PCG) are loaded with allergens. They are released from grass pollen grains following contact with water and can form a respirable allergenic aerosol. On the other hand, the traffic-related air pollutants NO₂ and O₃ are known to be involved in the current increase in the prevalence of allergic diseases via their adjuvant effects. Our objective was to determine the effects of air pollutants on the release of PCG from Phleum pratense (timothy grass) pollen. Methods:P. pratense pollen was exposed to several concentrations of NO₂ and O₃. The induced morphological damages were observed by environmental scanning electron microscopy, and the amount of PCG released from the pollen upon contact with water was measured. Results: The percentages of damaged grain were 6.4% in air-treated controls, 15% after treatment with the highest NO₂ dose (50 ppm) and 13.5% after exposure to 0.5 ppm O₃. In treated samples, a fraction of the grains spontaneously released their PCG. Upon subsequent contact with water, the remaining intact grains released more PCG than pollen exposed to air only. Conclusions: Traffic-related pollutants can trigger the release of allergen-containing granules from grass pollen, and increase the bioavailability of airborne pollen allergens. This is a new mechanism by which air pollution concurs with the current increase in the prevalence of allergic diseases.