The Interaction Of Aspergillus Fumigatus Infection And Organism And The Clinical Study

Aspergillus fumigatus is an important opportunistic pathogenic fungus,which widely exists in the natural environment,which cause invasive pulmonary aspergillosis(IPA)under certain conditions by inhalation.The incidence rate of IPA has been increasing and the mortality rate is high in recent years duing to the application of bone marrow and organ transplantation,tumor chemotherapy,glucocorticoid and broad-spectrum antibiotics.The development of IPA is the result of the interaction between host and pathogen.Natural immunity is the first step to resist pathogen invasion and the basis of all immune responses.The spores of Aspergillus fumigatus inhaled into the lungs can be clear up successfully depending on immune cells such as monocytes/macrophages,natural killer cells and airway epithelial cells.Macrophages in infected tissues are the outpost of natural immunity.They activate related signal networks and release cytokines through antigen presentation.Furthermore,it can induce neutrophil chemotaxis,kill pathogenic microorganisms,and mediate the differentiation and activation of immunoblasts,which is the bridge between host adaptive immunity and natural immunity.At present,the interaction between Aspergillus fumigatus and the body is not clear,such as the changes of pulmonary epithelial cells caused by Aspergillus fumigatus infection,the interaction between macrophages,NK cells and other natural immune cells after the invasion of Aspergillus fumigatus.We can further understand the role of tissue cells in the infection of Aspergillus fumigatus to find out the key regulatory molecules,which will provide new target for further control of Aspergillus fumigatus infection and treatment of invasive aspergillosis.1.Effect and mechanism of Aspergillus fumigatus on macrophage polarizationThe effect of Aspergillus fumigatus on macrophage polarization was measured by the phenotype,cytokines and intracellular transcription factors detection firstly.The results showed that the swollen spores of Aspergillus fumigatus caused the polarization of M1 macrophages.2.The regulation of Aspergillus fumigatus on macrophage and NK cellsCultured macrophages stimulated by swollen spores of Aspergillus fumigatus with natural killer cells to explore the changes of NK cell activation level and IFN-?secretion ability.Antibody neutralization test and gene silencing test were used to prove the molecular mechanism of Aspergillus fumigatus mediated macrophage regulating NK cell function.The results showed that the expansion spores of Aspergillus fumigatus induced the polarization of M1 macrophages,and increased the IFN-? secretion and CD69 expression of NK cells by secreting Gal-9.3.Protein expression profile of Aspergillus fumigatus on A549 cellsAspergillus fumigatus infect A549 in vitro,and established an in vitro model of invasive pulmonary epithelial cells.The proteomic data of interaction between Aspergillus fumigatus spores and A549 were obtained for the first time by i TRAQ technology,and several differential proteins were obtained It was found for the first time that NDRG-1 and CD44 could affect the endocytosis and the expression of inflammatory cytokines of A549.4.Function of macrophages and NK cells in invasive pulmonary aspergillosisThe bronchoalveolar lavage fluid of patients with pulmonary Aspergillus fumigatus infection was collected and tested the polarization characteristics of macrophages and the activation of NK cells.It was found that the macrophages in the bronchoalveolar lavage fluid of patients with invasive pulmonary Aspergillus fumigatus were mainly M1 type macrophages.After stimulation by the same cytokines,the NK cells from patients with IPA showed stronger activation level and IFN-? secretion ability.This is consistent with the results of our previous in vitro experiments.Conclusion:1.the swollen spores of Aspergillus fumigatus caused the aggregation of ITAM,which was the junction protein in the cell membrane,by binding the Dectin-1 and dectin-2 receptors on the surface of macrophages,and recruited a large number of Syk and ITAM to form complex,which further caused the phosphorylation of Syk.The phosphorylated Syk could induce the increase of downstream CARD9 expression,form trimer with BCL10 and MALT1,and induce downstream I?B?.In addition,the phosphorylation of Syk can activate STAT1 signaling pathway,further promote the polarization of M1 macrophages and the secretion of inflammatory cytokines.2.Macrophages secreted galectin-9 to enhance the expression of IFN-? and CD69,which may be one of the mechanisms of macrophages regulating NK cells.3.The proteomic data of interaction between Aspergillus fumigatus spores and alveolar epithelial cell A549 were obtained by i TRAQ and cellular information technology.It was found that NDRG-1 and CD44 could affect the endocytosis of A549 and the expression of inflammatory cytokines respectively,suggesting that there was a series of responses of pulmonary epithelial cells to Aspergillus fumigatus spores.4.The macrophages in the alveolar lavage fluid of patients with invasive pulmonary aspergillosis are mainly M1 type.After stimulated by IL-15/18,NK cells from the alveolar lavage fluid of IPA patients show stronger activation level and IFN-? secretion ability.From the perspective of clinical patients,it is proved that macrophages have a regulatory effect on NK cells when infected by Aspergillus.In conclusion,this study explored the role of Aspergillus fumigatus spores in stimulating macrophage polarization and the mechanism of interaction between macrophages and NK cells,and obtained proteomic data and key molecules of interaction between Aspergillus fumigatus spores and alveolar epithelial cell A549.In order to further understand the interaction between Aspergillus fumigatus and the body,as well as to provide theoretical basis and experimental support for the control of aspergillosis.