Change of the concentration of IFN-? and infectious Aspergillus organisms in lung in the model of invasive pulmonary aspergillosis / 中国实用内科杂志

ABSTRACT

Objective To establish the model of invasive pulmonary aspergillosis (IPA) and assay the influence on the host defense against Aspergillus infection when immunity was suppressed in mice.Methods Immunocompromised mice were made by treatment with cyclophosphamide administered intraperitoneally (i.p.).Suspension of conidia was applied to the nostrils of mice to make the model of IPA.Lungs were harvested and homogenized.Portions of homogenates were cultured to determine the number of CFU.IFN-? in bronchoalveolar lavage fluid was determined by a cytokine-specific ELISA kit.Reverse transcription PCR (RT-PCR) analysis was done to determine the mRNA of IFN-? in lung cells.Mortality of different rice was calculated.Results Compared with immunocompetent mice,the immunocompromised mice demonstrated a high mortality and had significantly higher concentration of infectious Aspergillus organisms in their lung tissues.In accordance with the increase of Aspergillus organisms,the levels of IFN-? in lung tissues got higher.Lung sections from immunocompromised mice revealed patterns of lesions characterized by signs of bronchial wall damage,peribronchial necrosis,and the presence of numerous infiltrating inflammatory cells.Conidia and hyphae were seen in these mice.In contrast,these features were not observed in immunocompetent mice whose lungs were characterized by few inflammatory cells infiltration,and few fungal growth after inoculation.Conclusion The levels of IFN-? in lung tissues are related to the infectious Aspergillus organisms.The immunity and T cells play a major role in host defense against Aspergillus infection.