Artemisia Pollen Extracts Exposed to Diesel Exhaust Enhance Airway Inflammation and Immunological Imbalance in Asthmatic Mice Model

Abstract

Background: Vehicle-induced air pollution may increase the prevalence and severity of asthma. Pollens are important sources of outdoor allergens associated with asthma. Outdoor pollution may influence the structure of pollen grains, resulting in enhanced immune reactions. Objective: This study aims to investigate the impact that artemisia pollen extracts exposed to diesel emissions (APEDE) may induceallergic airway inflammation, pulmonary pathology and immune imbalance -in mice. Methods: Sixty male Balb/c mice were equally randomized into 5 groups, sensitized with 30 μL artemisia pollen extracts (APE) or APEDE adsorbed on 2 mg aluminum hydroxide gel by intraperitoneal injection on day 0, 7, 14, and 22, and challenged intranasally once per day with 30 μL APE or APEDE from day 29 to 36. The control-ling group used phosphate-buffered saline as control. Results: In mice immunized and challenged by APEDE, the clinical phenotype of eosinophils, neutrophils in bronchoalveolar lavage fluid (BALF), tracheal wall thickness, airway smooth muscle thickness and airway resistance increased significantly. Pathophysiological parameters such as interleukin (IL)-17A and tumour necrosis factor-α production in BALF and serum, and the ratio of Th17/Treg cells in CD4 + cells increased significantly, while IL-10 in BALF and serum and the ratio of Treg cells decreased significantly. It was further found that the expression of oxidative stress marker 3-nitrotyrosine (3-NT) and the activation of nuclear factor kappa B (NF-κB) were significantly increased. The correlation analysis showed that the expression of 3-NT was positively correlated with the activation of NF-κB. Conclusion: Our findings suggested that pollens exposed to diesel exhaust enhance allergic responses, which may contribute to an increased prevalence of allergic diseases in urban environments with serious exhaust emissions.

Atmospheric pollutants and their association with olive and grass aeroallergen concentrations in Córdoba (Spain)

“…Depending on the plant species and on the pollutant type and concentration, this interaction may modify the vitality, shape, size, physiologic features, and metabolism of the pollen grain (Malayeri et al 2012 ). In recent studies, air pollution induced structural changes in macromolecules of mugwort pollen (Chen et al, 2020 ; Depciuch et al, 2016 ), which might contribute to an increment prevalence of allergic diseases in urban environs.…”

Quantitative assessment of coagulation of atmospheric particles onto airborne birch pollen grains

“…Furthermore, the sampling was conducted on the roof of a building (20 m high); sampling at 1.5 m above the ground could promote soot-pollen coagulation because, on the one hand, airborne particle concentrations can be as high as 10 6 to 10 7 particles per cm 3 (Seinfeld & Pandis, 2016) and, on the other hand, pollen concentrations can be higher (Charalampopoulos et al, 2021). Further sampling, especially at street level, is therefore necessary to better assess the fraction of PGs polluted by soot, especially as a large body of literature highlights the aggravating effects on allergy of co-exposure to pollen and soot (Chen et al, 2020;Nel et al, 1998;Shiraiwa et al, 2012). Unlike nasal co-deposition (Figure 5), the pollen and soot (or pollen and particles) mixture resulting from atmospheric coagulation may have time (up to several days) to undergo atmospheric aging.…”