Impact of urbanization on the proteome of birch pollen and its chemotactic activity on human granulocytes.
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.
Bryce
M
M
Division of Environmental Dermatology and Allergy, Helmholtz Center Munich/TUM, ZAUM - Center of Allergy and Environment, Technische Universität, Munich, Germany.
Drews
O
O
Schenk
M F
MF
Menzel
A
A
Estrella
N
N
Weichenmeier
I
I
Smulders
M J M
MJ
Buters
J
J
Ring
J
J
Görg
A
A
Behrendt
H
H
Traidl-Hoffmann
C
C
D000595:Amino Acid Sequence; D054458:Amplified Fragment Length Polymorphism Analysis; D029662:Betula / Q000235:genetics / Q000276:immunology*; D002465:Cell Movement / Q000187:drug effects* / Q000276:immunology; D002478:Cells, Cultured; D002633:Chemotaxis / Q000187:drug effects / Q000276:immunology*; D006098:Granulocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010936:Plant Extracts / Q000494:pharmacology; D011058:Pollen / Q000276:immunology*; D020543:Proteome / Q000276:immunology* / Q000378:metabolism; D040901:Proteomics; D014507:Urbanization
D010936:Plant Extracts; D020543:Proteome