Project description:Lung alveolar macrophages are self-renewing tissue resident macrophages primarily relying upon GM-CSF signal as a main source. We used microarrays to detail the global programme of gene expression underlying homeostasis and functions of alveolar macrophages in absence of phosphatase Ssu72
Project description:The objective of this study was to examine transcriptional changes in alveolar macrophages early after reperfusion in a model of murine lung transplant.
Project description:Bacterial lung infections are associated with strong infiltration of CD11b+ myeloid cells, which limit life-threatening disease, but also severely damage lung tissue. In a murine lung infection model with Streptococcus pneumoniae, we found intrinsic upregulation of CD11b on resident alveolar macrophages. Such CD11b expression was associated with transcriptomic and proteomic adaptations by alveolar macrophages, leading to the identification of specific molecules and pathways that depended on CD11b. In the absence of CD11b, the antimicrobial defense of alveolar macrophages was strongly reduced, and the production of neutrophil-recruiting chemokines was more pronounced. Moreover, CD11b expression limited the infection and prevented excessive alveolar damage. In conclusion, our study provides detailed molecular insights into the alveolar macrophage-specific immune response to Streptococcus pneumoniae lung infection and reveals profound CD11b-dependent alterations that are critical for effective antimicrobial immunity, neutrophil recruitment, and prevention of alveolar damage.
Project description:To investigate the interaction between lung alveolar macrophages and lung cancer cells in vivo, gene expression analysis was performed using orthotopic tumor bearing animal model with C57BL/6 mice and Lewis Lung Carcinoma (LLC) cells. CD45+, F4/80+, Siglec-F+ population was sorted as alveolar macrophage population with fluorescence-activated cell sorting (FACS) technique.
Project description:Rationale: Lipopolysaccharide (LPS) is ubiquitous in the environment. Inhalation of LPS has been implicated in the pathogenesis and/or severity of several lung diseases, including pneumonia, chronic obstructive pulmonary disease and asthma. Alveolar macrophages are the main resident leukocytes exposed to inhaled antigens. Objectives: To obtain insight into which innate immune pathways become activated within human alveolar macrophages upon exposure to LPS in vivo. In seven healthy humans sterile saline was instilled into a lung segment by bronchoscope, followed by instillation of LPS into the contralateral lung. Six hours later a bilateral bronchoalveolar lavage was performed and whole-genome transcriptional profiling was done (Affymetrix HG-U133 Plus 2.0) on purified alveolar macrophages, comparing cells exposed to saline or LPS from the same individuals.
Project description:Little is known about the relative importance of monocyte and tissue-resident macrophages in the development of lung fibrosis. We show that specific genetic deletion of monocyte-derived alveolar macrophages after their recruitment to the lung ameliorated lung fibrosis, whereas tissue-resident alveolar macrophages did not contribute to fibrosis. Using transcriptomic profiling of flow-sorted cells, we found that monocyte to alveolar macrophage differentiation unfolds continuously over the course of fibrosis and its resolution. During the fibrotic phase, monocyte-derived alveolar macrophages differ significantly from tissue-resident alveolar macrophages in their expression of profibrotic genes. A population of monocyte-derived alveolar macrophages persisted in the lung for one year after the resolution of fibrosis, where they became increasingly similar to tissue-resident alveolar macrophages. Human homologues of profibrotic genes expressed by mouse monocyte-derived alveolar macrophages during fibrosis were up-regulated in human alveolar macrophages from fibrotic compared with normal lungs. Our findings suggest that selectively targeting alveolar macrophage differentiation within the lung may ameliorate fibrosis without the adverse consequences associated with global monocyte or tissue-resident alveolar macrophage depletion.
Project description:To classify the cell population of lung alveolar macrophages in the presence (or absence) of lung cancer cells in vivo, single cell RNA sequence analysis was performed using orthotopic tumor bearing animal model with C57BL/6 mice and Lewis Lung Carcinoma (LLC) cells. CD45+, F4/80+, Siglec-F+ population was sorted as alveolar macrophage population with fluorescence-activated cell sorting (FACS) technique.
Project description:Analyzing the kenetics of alveolar macrophage turnover after human lung transplantation and identifying protein and transcriptional differences between donor and recipient-derived alveolar macrophages