Immunological Interactive Effects between Pollen Grains and Their Cytoplasmic Granules on Brown Norway Rats

International audienceBackgroundGrass pollen is one of the most important aeroallergen vectors in Europe. Under some meteorological factors, pollen grains can release pollen cytoplasmic granules (PCGs). PCGs induce allergic responses. Several studies have shown that during a period of thunderstorms the number of patients with asthma increases because of higher airborne concentrations of PCGs.ObjectiveThe aims of the study were to assess the allergenicity of interactive effects between pollen and PCGs and to compare it with allergenicity of Timothy grass pollen and PCGs in Brown Norway rats.MethodsRats were sensitized (day 0) and challenged (day 21) with pollen grains and/or PCGs. Four groups were studied: pollen-pollen (PP), PCGs-PCGs (GG), pollen-PCGs (PG), and PCGs-pollen (GP). Blood samples, bronchoalveolar lavage fluid, and bronchial lymph node were collected at day 25. IgE and IgG1 levels in sera were assessed by enzyme-linked immunosorbent assay. Alveolar cells, protein, and cytokine concentrations were quantified in bronchoalveolar lavage fluid. T-cell proliferation, in response to pollen or granules, was performed by lymph node assay.ResultsInteractive effects between pollen and PCGs increased IgE and IgG1 levels when compared with those of the negative control. These increases were lower than those of the PP group but similar to the levels obtained by the GG group. Whatever was used in the sensitization and/or challenge phase, PCGs increased lymphocyte and Rantes levels compared with those of the pollen group. The interactive effects increased IL-1α and IL-1β compared with those of the PP and GG groups.ConclusionsImmunologic interactive effects have been shown between pollen and PCGs. For humoral and cellular allergic responses, interactive effects between the 2 aeroallergenic sources used in this study seem to be influenced mainly by PCGs

Allergénicité des Granules Cytoplasmiques de Pollen

Grass pollen is one of the most important aeroallergen vectors in Europe. It highly contributes to respiratory allergic diseases such as asthma or allergic rhinitis. In contact to water or airborne pollutants, pollen grains can release microparticles or pollen cytoplasmic granules. Because of their size (<5 !m), granules may penetrate deeper into the lungs than pollen grains and so, can induce stronger allergic responses. The aim of this study was to characterized allergic potential of pollen cytoplasmic granules along 3 axes: epidemiological, experimental and analytical. Results of the epidemiological study involve a possible effect of granules in the onset of allergic reparatory diseases, in particular asthma. In experimental part, the results show that granules induced allergic - both humoral and cellular - and inflammatory responses. These results are compared with whole pollen, on a good animal model of allergy, the Brown Norway rat. Finally, according to the results of the analytical study, both water-soluble and water-insoluble allergens of granules contribute to the allergenicity of these microparticles.Le pollen des Graminées est l'un des principaux vecteurs d'allergènes. Il contribue à l'apparition des allergies respiratoires comme l'asthme et la rhinite allergique. En contact avec l'eau de pluie ou des polluants atmosphériques, le pollen peut libérer des microparticules (<5 !m) dites granules cytoplasmiques de pollen. À cause de leur taille, ces granules peuvent pénétrer plus profondément dans l'appareil respiratoire que le pollen entier et induire ainsi des réactions allergiques. L'objectif de ce travail est de caractériser l'allergénicité de ces granules selon 3 volets : épidémiologique, expérimental et analytique. Les résultats de l'étude épidémiologique mettent évidence un effet éventuel des granules dans la survenue des allergies respiratoires, et plus particulièrement de l'asthme. Dans la partie expérimentale, les résultats obtenus permettent de montrer que les granules induisent des réactions allergiques, humorales et cellulaires ainsi que des réponses inflammatoires, comparables au pollen entier, chez le rat Brown Norway, le modèle animal d'allergie ici utilisé. Enfin, la partie analytique permet de conclure que l'allergénicité des granules dépend à la fois de leur contenu en allergènes hydrosolubles et non-hydrosolubles

Allergénicité dez Granules Cytoplasmiques de Pollen

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Synergie pollen-polluants et rôle des facteurs météorologiques sur le risque de pollinose : évolution des consultations dans la région amiénoise pendant la saison pollinique 2007

National audienceBACKGROUND. - Respiratory allergic diseases are currently a major public health problem worldwide, especially in industrialized countries. Although the symptoms associated with these affections coincide with the pollination season, it is now well established that simple and direct relations do not exist between these two phenomena and that, in the same time, several other factors - air pollutants and meteorological factors - must be taken into account. OBJECTIVE. - To correlate atmospheric parameters with the medical consultations in response to rhinitis and asthma symptoms. METHODS. - This study was conducted in the city of Amiens, during the pollen season in 2007. Clinical results were provided from the Picardie Regional Health Observatory. The atmospheric data gathered the count of pollen grains, the concentrations of gaseous air pollutants and several meteorological parameters. The correlations between these parameters are carried out using simple and multiple linear regressions. RESULTS. - The consultations for rhinitis were positively correlated with grass pollen counts and atmospheric ozone, whereas asthma was correlated with precipitations. The results of multiple linear regressions showed that the two allergic symptoms, rhinitis and asthma, were related to several atmospheric factors, in particular airborne grass pollen, gaseous pollutants and temperature. CONCLUSION. - The large size of pollen grains could explain the simple relationship between rhinitis and grass pollen, because pollen grains can penetrate only the higher respiratory tract. This effect was not observed for asthma, but a positive relationship between asthma and precipitation suggests a potential role of pollen cytoplasmic granules. Theses granules could massively increase asthma attacks during the pollen season.INTRODUCTION. - Depuis plusieurs décennies, une augmentation de la fréquence des allergies respiratoires est régulièrement observée. Bien que ces affections coïncident avec les périodes de pollinisation, il n'existe pas de relation univoque entre ces deux phénomènes. De nombreux autres facteurs - dont les polluants atmosphériques et les facteurs météorologiques - doivent être pris en compte. OBJECTIF. - Corréler les paramètres atmosphériques avec le nombre de consultations faisant suite à des crises allergiques, pendant la période pollinique 2007. METHODES. - L'étude est menée sur la ville d'Amiens. Les données cliniques sont fournies par l'Observatoire régional de la santé et du social. Les données atmosphériques concernent des comptages polliniques, des taux de polluants atmosphériques et différents paramètres météorologiques. Les corrélations entre ces facteurs sont effectuées en utilisant des modèles de régression linéaire simple et multiple. RESULTATS. - Les consultations pour rhinites sont corrélées positivement avec le pollen des Graminées et le taux d'ozone atmosphérique alors que l'asthme se trouve corrélé avec les précipitations. Les résultats des régressions linéaires multiples permettent de montrer que les rhinites et l'asthme sont liés à plusieurs facteurs atmosphériques, notamment les polluants gazeux, la température et la présence de pollen des Graminées. CONCLUSION. - Une partie importante des pics de consultations pour allergie respiratoire semble coïncider avec les pics de pollinisation. Ainsi, une relation simple a été trouvée entre la rhinite et le pollen de Graminées sur la période prise en compte. En revanche, les granules cytoplasmiques de pollen pourraient intervenir dans la survenue de crises d'asthme sans relation directe avec les pics de consultations

Genotoxicity of organic extracts of urban airborne particulate matter : an assessment within a personal exposure study

International audienceAirborne particulate matter, PM10 and PM2.5, are associated with a range of health effects including lung cancer. Their complex organic fraction contains genotoxic and carcinogenic compounds such as polycyclic aromatic hydrocarbons (PAHs) and their derivatives. This study evaluates the genotoxicity of the PM10 and PM2.5 organic extracts that were sampled in the framework of a personal exposure study in three French metropolitan areas (Paris, Rouen and Strasbourg), using the comet assay, performed on HeLa S3 cells. In each city, 60-90 non-smoking volunteers composed of two groups of equal size (adults and children) carried the personal Harvard Chempass multi-pollutant sampler during 48 It along two different seasons ('hot' and 'cold'). Volunteers were selected so as to live (home and work/school) in 3 different urban sectors contrasted in terms of air pollution within each city (one highly exposed to traffic emissions, one influenced by local industrial sources, and a background urban environment). Genotoxic effects are stronger for PM2.5 extracts than for PM10, and greater in winter than in summer. Fine particles collected by subjects living within the traffic proximity sector present the strongest genotoxic responses, especially in the Paris metropolitan area. This work confirms the genotoxic potency of particulate matter (PM 10 and PM2.5) organic extracts to which urban populations are exposed