Human IgE production in hu-PBL-SCID mice injected with birch pollen and diesel exhaust particles

An Overview of Rising CO₂ and Climatic Change on Aeroallergens and Allergic Diseases

There are a number of implications of climate change in regard to human health. Among these, the role of rising carbon dioxide (CO₂) and temperature in aeroallergen exposure and associated changes in the start, duration and intensity of the pollen season, and associated consequences in aeroallergens and allergic disease are a primary concern. This review is intended to provide a synopsis of CO₂ and climate factors associated with likely changes in aeroallergen biology (indoor and outdoor), including changes in the demography of flowering plants, pollen seasonality, aeroallergen production, and potential biotic and abiotic interactions. These factors, in turn, are compared to clinical trials that have linked aeroallergens to allergic disease and associated health impacts. Finally, suggestions to address unmet needs and critical knowledge gaps are offered. Such recommendations are not meant to be inclusive, but to serve as a spur for the additional research and resources that will be necessary to acquire a better understanding of climate change, CO₂, aeroallergens and associated allergic diseases. Such resources will be critical to derive time-relevant scientific and policy solutions that will minimize public health consequences in a changing climate.

A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity

This review summarizes the available data related to the effects of air pollution on pollen grains from different plant species. Several studies carried out either on in situ harvested pollen or on pollen exposed in different places more or less polluted are presented and discussed. The different experimental procedures used to monitor the impact of pollution on pollen grains and on various produced external or internal subparticles are listed. Physicochemical and biological effects of artificial pollution (gaseous and particulate) on pollen from different plants, in different laboratory conditions, are considered. The effects of polluted pollen grains, subparticles, and derived aeroallergens in animal models, in in vitro cell culture, on healthy human and allergic patients are described. Combined effects of atmospheric pollutants and pollen grains-derived biological material on allergic population are specifically discussed. Within the notion of "polluen," some methodological biases are underlined and research tracks in this field are proposed.

Analysis of liquid extracts from tree and grass pollens by capillary electromigration methods

Capillary electromigration methods, zone electrophoresis (CZE), micellar electrokinetic chromatography (CMEKC) and isotachophoresis (CITP), have been used for analysis of water and water-buffer extracts from tree-common birch (Betula verrucosa) and grass-orchardgrass (Dactylis glomerata) pollen samples. Water extracts were analyzed by CZE using acetic acid as background electrolyte (BGE), by CMEKC in tris-phosphate BGE with anionic detergent sodium dodecyl sulfate (SDS) micellar pseudophase (TP-SDS) and by CITP in cationic mode with leading/terminating cations K+/BALA+ (beta-alanine (BALA)) and in anionic mode with leading/terminating anions Cl-/MES- (2-(N-morpholino)ethanesulphonic acid (MES)). Moreover, acetic acid extracts were analyzed by CZE using acetic acid as BGE, and alkaline water-SDS-buffer extracts were analyzed by CMEKC using TP-SDS as BGE. Extracted amounts of pollen allergens and other UV-absorbing compounds and the number of resolved components were evaluated from CZE, CMEKC and CITP analyses of the liquid extracts. Larger amounts of UV-absorbing material were found in the water-buffer pollen extracts than in the water extracts. More UV-absorbing material was found in all extracts from D. glomerata pollen than in relevant extracts from B. verrucosa pollen. It was found by CITP that the extracted amounts of anionic components and their number were much higher than those of cationic components. Concentrations of some inorganic ions (e.g. Cl-, K+, Na+, Ca2+) in pollen samples were also determined by CITP.

Analysis of water extracts from airborne dust samples by capillary isotachophoresis

Application of capillary isotachophoresis (CITP) for the analysis of water extracts of the dust samples collected in different periods in air-filtration devices in Prague car traffic tunnels and in Parisian metro station is presented. The extracts were analyzed in cationic mode with a leading electrolyte (LE) of 10 mM KOH, 25 mM acetic acid, pH 4.4, and a terminating electrolyte (TE) of 10 mM beta-alanine, adjusted to pH 4.4 with acetic acid, and in anionic mode with LE 10 mM HCl, 20 mM histidine, pH 5.8 and TE 10 mM 2-(N-morpholino)ethanesulphonic acid, pH 3.7. Extracted amounts of UV-absorbing substances, including pollen allergens and organic pollutants, the number of the found components and concentrations of some inorganic ions (e.g. Cl-, K+, Na+, Ca2+) in the dust samples were determined. It was found that the extracted amounts of anionic components and their number were much higher than those of cationic components. Significant differences have been found in the analyses of the extracts of different origin. Much more material and more components were present in the extracts of samples from the pollen-rich period than from the pollen-free period, especially in anionic CITP mode.

Short-term effects of low-level air pollution on respiratory health of adults suffering from moderate to severe asthma

Only a few studies have been carried out on the health effects of air pollution on patients suffering from severe asthma. We wanted to test the sensitivity of these patients to Paris air pollution. During 13 months, 60 severe asthmatics (62- female; mean age 55 years) were monitored by their physician, who filled in a follow-up form at each consultation and reported any asthma attacks. Daily levels of SO(2), PM10, NO(2), and O(3) were provided by the air quality network. Statistical analysis (generalized estimating equation models that accounted for autocorrelation of responses, temporal, meteorological, and aerobiological variables, and some individual characteristics) revealed significant associations between PM10, O(3), and incident asthma attacks. Odds Ratio (OR) for an increase of 10 microg/m(3) of PM10 was 1.41; 95% confidence interval (CI) [1.16; 1.71]. An increase of 10 microg/m(3) of O(3) was significantly associated with asthma attacks; OR=1.20; 95% CI [1.03; 1.41]. These relations were observed after a delay between exposure and asthma attacks of 3 to 5 days for PM10 and 2 days for O(3), and they tended to differ according to atopic status. The results of our study suggest that ambient Paris levels of PM10 and O(3) affected health of severe asthmatics, despite their treatment.

Evaluation of the efficiency of extraction of ultraviolet-absorbing pollen allergens and organic pollutants from airborne dust samples by capillary electromigration methods

Capillary electromigration methods, zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC), have been used for evaluation of the efficiency of different extraction agents applied to the extraction of pollen allergens and organic pollutants from dust samples collected during different periods (before, during and after pollen seasons) and in different locations in air-filtration devices (car-traffic tunnel in Prague and a metro station in Paris). Water and acetic acid extracts were analyzed by CZE using acetic acid as background electrolyte (BGE). Water and alkaline water-SDS-buffer extracts were analyzed by MEKC in Tris-phosphate BGE with anionic detergent sodium dodecylsulfate (SDS) micellar pseudophase. More material was extracted and more components were found in the water-buffer extracts than in the water extracts, and better resolution of the components was achieved by MEKC than by CZE. Significant differences have been found in the analyses of dust extracts of different origin. More material and more components have been found in the extracts of the dust collected in the pollen-rich period (March, April) than in the pollen-free period (December, January).

Elevated serum immunoglobulin E to Cryptomeria japonica pollen in rats exposed to diesel exhaust during fetal and neonatal periods

BACKGROUND: The possible participation of diesel exhaust inhalation during the fetal period in the elevation of IgE against pollen in postnatal life was investigated. METHOD: The experiment was conducted using rat pups. Group I; exposed to clean air (Control). Group 2, 3; exposed to total or filtered diesel exhaust during the fetal period (Total-C-C, Filtered-C-C). Group 4, 5; exposed to total or filtered diesel exhaust during the suckling period (C-Total-C, C-Filtered-C). Group 6,7; exposed to total or filtered diesel exhaust during the weaning period (C-C-Total, C-C-Filtered). Total diesel engine exhaust contained 1.73 mg/m3 particulate matter and 0.79 ppm nitrogen dioxide; filtered exhaust contained the same gases as the total exhaust without particulate matter. Intraperitoneal injection of 5 mg crude cedar pollen was performed at 2-week intervals from the 49th day after birth. RESULTS: The mean IgE titers measured by the P-K reaction in the Control, Total-C-C, Filtered-C-C, C-Total-C, C-Filtered-C, C-C-Total and C-C-Filtered were 64.0 &PlusMinus; 2.7, 469.5 &PlusMinus; 1.6, 332.0 &PlusMinus; 1.7, 380.4 &PlusMinus; 1.7, 394.8 &PlusMinus; 1.7, 115.9 &PlusMinus; 1.3 and 57.0 &PlusMinus; 2.8 respectively after the fourth immunization. There were significant differences between Total-C-C, Filtered-C-C, C-Total-C, C-Filtered-C and Control (p < 0.01, p < 0.01, p < 0.05, p < 0.01, respectively). The mean IgE titers by ELISA were 0.47 &PlusMinus; 0.06, 0.79 &PlusMinus; 0.35, 0.86 &PlusMinus; 0.46, 0.80 &PlusMinus; 0.22, 0.56 &PlusMinus; 0.08, 0.46 &PlusMinus; 0.04 and 0.45 &PlusMinus; 0.03, respectively. IgE titers in Filtered-C-C and C-Total-C were significantly higher than in Control (p < 0.05 for each). CONCLUSIONS: Inhalation of diesel exhaust during differentiation of the immune system accelerated the elevation of IgE against pollen.

Diesel exhaust and asthma: hypotheses and molecular mechanisms of action

Several components of air pollution have been linked to asthma. In addition to the well-studied critera air pollutants, such as nitrogen dioxide, sulfur dioxide, and ozone, diesel exhaust and diesel exhaust particles (DEPs) also appear to play a role in respiratory and allergic diseases. Diesel exhaust is composed of vapors, gases, and fine particles emitted by diesel-fueled compression-ignition engines. DEPs can act as nonspecific airway irritants at relatively high levels. At lower levels, DEPs promote release of specific cytokines, chemokines, immunoglobulins, and oxidants in the upper and lower airway. Release of these mediators of the allergic and inflammatory response initiates a cascade that can culminate in airway inflammation, mucus secretion, serum leakage into the airways, and bronchial smooth muscle contraction. DEPs also may promote expression of the T(subscript)H(/subscript)2 immunologic response phenotype that has been associated with asthma and allergic disease. DEPs appear to have greater immunologic effects in the presence of environmental allergens than they do alone. This immunologic evidence may help explain the epidemiologic studies indicating that children living along major trucking thoroughfares are at increased risk for asthmatic and allergic symptoms and are more likely to have objective evidence of respiratory dysfunction.

The allergen-induced airway hyperresponsiveness in a human-mouse chimera model of asthma is T cell and IL-4 and IL-5 dependent

The cellular and molecular mechanisms involved in the airway hyperresponsiveness (AHR) of patients with allergic asthma remain unclear. A role for Th2 inflammatory cells was suggested based on murine asthma models. No direct evidence exists on the role of these cells in human asthma. The development of a mouse-human chimera might be useful, allowing the in vivo study of the components of the human immune system relevant to asthma. We investigated the role of allergen-reactive T lymphocytes in a human-mouse SCID model. SCID mice were reconstituted intratracheally with human PBMC from healthy, nonallergic, nonasthmatic donors and exposed to an aerosol of house dust mite allergen after i.p. injection with Dermatophagoides pteronyssinus I Ag and alum. The donor T lymphocytes had a Th1 cytokine phenotype. The reconstituted and allergen-challenged mice developed AHR to carbachol. The mouse airways and lungs were infiltrated with human T lymphocytes. No eosinophils or increases in human IgE were observed. The intrapulmonary human T lymphocytes demonstrated an increase in intracytoplasmic IL-4 and IL-5 and a decrease in IFN-gamma after exposure to allergen adjuvant. Antagonizing human IL-4/IL-13 or IL-5 resulted in a normalization of the airway responsiveness, despite a sustained intracellular Th2 cytokine production. These results provide evidence that the activated human allergen-reactive Th2 cells producing IL-4 or IL-5 are pivotal in the induction of AHR, whereas no critical role for eosinophils or IgE could be demonstrated. They also demonstrate that human allergen-specific Th1 lymphocytes can be driven to a Th2 phenotype.

Interleukin-13 and human immunoglobulin E production in severe combined immunodeficiency mice transplanted with human peripheral blood lymphocytes

As normal mice do not respond to interleukin-13 (IL-13), we have used mice with severe combined immunodeficiency transplanted with human peripheral blood lymphocytes (hu-PBL-SCID mice) as an in vivo model for studying human IL-13. PBL from three donors (two allergic and one non-allergic) were prestimulated with IL-13 in vitro and thereafter transplanted into SCID mice. As evidenced by flow cytometry, IL-13 in the in vitro cell cultures was physiologically active and suppressed CD14 expression, while it enhanced the expression of CD23 on human monocytes. In the in vivo experiments, SCID mice transplanted with cells from both allergic donors produced twice as high maximum levels of IgE when the cells were preincubated with IL-13 in vitro before transplantation, as compared with mice receiving cells that had not been preincubated with IL-13. Two succeeding intraperitoneal (i.p.) injections of IL-13 resulted in a further increase of maximum IgE levels. Using cells from the non-allergic donor, no enhancing effect of IL-13 was observed. Transplanted human cells from one allergic donor examined were shown to migrate to the spleen and lungs of the recipient mice, while cells from the non-allergic donor were found only in the peritoneal cavity. Altogether, our results indicate that IL-13 enhances human IgE production in vivo and suggest that lymphocytes in allergic individuals are hyper-reactive to this cytokine. Furthermore, the allergic status of the cell donor may affect migration and engraftment of cells transplanted into SCID mice.