ObjectiveTo explore the effect of Aspergillus fumigatus on airway eosinophilia and hyperresponsiveness in rat model of chronic asthma. MethodsWistar rats were sensitized by intraperitoneal injections with ovalbumin (OVA) followed by chronic inhalation of nebulized OVA or physiologic saline. Rats were administered via the airways with placebo or aerosolized Aspergillus fumigatus spores suspension mimicking chronic Aspergillus fumigatus exposure. The Penh after acetylcholine provocation was detected using WBP system. The concentrations of IL-5 and eotaxin in BALF were measured by ELISA. The extents of eosinophil infiltration were evaluated on hematoxylin and eosin-stained(HE) and Wright-Giemsa stained BALF cells smear. ResultsAspergillus fumigatus worsened allergic airway inflammation in OVA-challenged rats,as evidenced by enhanced bronchial responsiveness to inhaled acetylcholine and increased bronchial eosinophilia. Elevated airway eosinophilia corresponded with higher levels of IL-5 and eotaxin in the Aspergillus Fumigatus exposure group. Aspergillus fumigatus,however,did not affect bronchial responses,numbers of eosinophils,IL-5 and eotaxin levels in saline challenged mice. ConclusionThe Results show that chronic Aspergillus fumigatus exposure aggravates eosinophilic airway inflammation in asthma rats by enhancing IL-5 and eotaxin production. Aspergillus fumigatus also increases bronchial hyperresponsiveness in asthma rats.
ObjectiveTo explore the effects of Aspergillus fumigatus (A. fumigatus) on airway inflammation, airway responsiveness and total serum IgE in asthmatic rats. MethodsEighteen male Wistar rats were divided into three groups randomly, ie. a normal control group, an asthmatic model group, and an A. fumigatus group. The rats in the model group and the A.fumigatus group were sensititized and challenged with ovalbumin to establish asthmatic model. After establishment of asthmatic model, the rats in the A. fumigatus group were treated with chronic A. fumigatus spores inhalation. Subsequently, airway responsiveness/sensitivity to methacholine(Ach), levels of serum IgE and airway inflammation were assessed and compared among three groups. ResultsCompared with the asthmatic rats, the rats treated with A. fumigatus showed higher airway responsiveness (Penh/baselin value was significantly increased at the Mch concentration of 12.5, 25 and 50 mg/mL), increased inflammatory cells infiltration in pulmonary tissue slices and increased serum IgE level (P < 0.05). Most importantly, serum IgE level was detected in close relationship with PC100 which was defined as the dose of Mch causing 100% increase of enhance pause (Penh) value without Mch challenge (r=-0.873, P < 0.01). Serum IgE level was also closely related to the percentage of eosinophils in bronchoalveolar lavage fluid (r=0.937, P < 0.01). ConclusionsChronic A. fumigatus inhalation aggravates airway inflammation, bronchial hyperresponsiveness and serum IgE level in asthma. IgE may play an important role in facilitating the development of bronchial responsiveness and eosinophilic inflammation.
Objective To explore the method of radiolabeling anti-Aspergillus monoclonal antibody (WF-AF-1)with 99mTc,and evaluate the in vitro and in vivo characteristics of 99mTc labeled WF-AF-1 (99mTc-WF-AF-1). Methods 99mTc-WF-AF-1 was prepared with indirect-labeling method.The labeled product was identified using thin layer chromatography.Suspensions of Aspergillus fumigatus,Staphylococcus aureus and Candida albicans were incubated with 99mTc-WF-AF-1 to evaluate the specificity of the labeled antibody.Mice were injected with 3.7MBq of labeled product.The biodistribution was measured at 40min,2h,4h and 7h after injection. Results The labeling efficiency of 99mTc-WF-AF-1 was over 95%,and the labeled product was stable in serum and phosphate buffer solution.In vitro binding of 99mTc-WF-AF-1 revealed that the labeled Mab-WF-AF-1 preferentially binds to Aspergillus fumigatus. Biodistrbution data showed that the labeled antibody was deposited mainly in liver,kidneys and spleen.The radioactivity uptake in blood at 40min and 7h was (2.51±0.23)%ID/g and (0.53±0.13)%ID/g,respectively. Conclusions The labeling efficiency and stability of 99mTc-WF-AF-1 are high.The labeled antibody is excreted mainly through the liver and kidneys with fast clearance in blood in normal mice.