Project description:Despite their importance in lung health and disease, it remains unknown how human alveolar macrophages develop early in life. In this study we identified the fetal progenitor of human alveolar macrophages. We used microarray to define the gene signatures of human CD14+ blood monocytes (adult AM precursors), CD116+CD64+ fetal liver monocytes, and CD116+CD64- fetal AM precursors.
Project description:comparison of Alveolar macrophge gene expression in wild type and PIKfyve ko We identifed gene that important for alveolar macrophage development
Project description:Macrophage activation syndrome (MAS) is a life-threatening cytokine storm syndrome complicating systemic juvenile idiopathic arthritis (SJIA) and driven by IFN-gamma. SJIA and MAS are also associated with an unexplained emerging inflammatory lung disease (SJIA-LD), with our recent work supporting pulmonary activation of IFN-gamma pathways as a pathologic link between SJIA-LD and MAS. Our objective was to mechanistically define the novel observation of pulmonary inflammation in the TLR9 mouse model of MAS. In acute MAS, lungs exhibit mild but diffuse CD4-predominant, perivascular interstitial inflammation with elevated IFN-gamma, IFN-induced chemokines, and alveolar macrophage expression of IFN-gamma-induced genes. Single-cell RNA-sequencing confirmed IFN-driven transcriptional changes across immune and parenchymal lung cell types. Resolution of MAS was associated with increased alveolar macrophage and interstitial lymphocytic infiltration. alveolar macrophage microarrays confirmed IFN-gamma-induced proinflammatory polarization during acute MAS, which switches towards an anti-inflammatory phenotype during MAS resolution. Interestingly, recurrent MAS led to increased alveolar inflammation and lung injury, and reset alveolar macrophagepolarization towards a proinflammatory state. Furthermore, in mice bearing macrophages insensitive to IFN-gamma, both systemic feature of MAS and pulmonary inflammation were attenuated. These findings demonstrate that experimental MAS induces IFN-gamma-driven pulmonary inflammation replicating key features of SJIA-LD, and provides a model system for testing novel treatments directed towards SJIA-LD.
Project description:GM-CSF receptor-β deficient (Csf2rbâ/â or KO) mice develop a lung disease identical to hereditary pulmonary alveolar proteinosis (hPAP) in humans with recessive CSF2RA or CSF2RB mutations that impair GM-CSF receptor function. We performed pulmonary macrophage transplantation (PMT) of bone marrow derived macrophages (BMDMs) without myeloablation in Csf2rbâ/âmice. BMDMs were administered by endotracheal instillation into 2 month-old Csf2rbâ/â mice. Results demonstrated that PMT therapeutic of hPAP in Csf2rbâ/â mice was highly efficacious and durable. Alveolar macrophages were isolated by bronchoalveolar lavage one year after administration subjected to microarray analysis to determine the effects of PMT therapy on the global gene expression profile. Total mRNA was isolated from alveolar macrophages PMT-treated Csf2rbâ/âmice (PMT) and from age-matched, untreated KO mice (KO) and wild-type (C57Bl/6) mice (WT). Total mRNA was evaluated using Affymetrix microarrays (Mouse Gene 1.0 ST Array) to compare the gene expression profiles among the three groups (3 mice/group).
Project description:The impact of cell origin on human lung macrophage identity and function remains unknown. In this study we characterized human alveolar macrophages of fetal versus adult origin. We used microarray to define the gene signatures of human alveolar macrophages derived from CD116+CD64+ fetal monocytes, CD116+CD64- fetal precursors, and CD34+ HSPCs in MISTRG humanized mice.
Project description:Tissue-resident macrophage-based immune therapies have been proposed for various diseases. However, generation of sufficient numbers that possess tissue-specific functions remains a major handicap. Here, we show that fetal liver monocytes cultured with GM-CSF (CSF2-cFLiMo) rapidly differentiate into a long-lived, homogeneous alveolar macrophage (AM)-like population in vitro. CSF2-cFLiMo remained the capacity to develop into bona fide AM upon transfer into Csf2ra-/- neonates and prevented development of alveolar proteinosis and accumulation of apoptotic cells for at least 1 year in vivo. CSF2-cFLiMo more efficiently engrafted empty AM niches in the lung and protected mice from severe pathology induced by respiratory viral infection, compared to transplantation of macrophages derived from bone marrow cells cultured with M-CSF (CSF1-cBMM) in the presence or absence of GM-CSF. Harnessing the potential of this approach for gene therapy, we restored a disrupted Csf2ra gene in FLiMo and demonstrated their capacity to develop into AM in vivo. Together, we provide a novel platform for generation of immature AM-like precursors amenable for genetic manipulation, which will be useful to dissect AM development and function and pulmonary transplantation therapy.
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:Our study shows that the aging lung microenvironment shapes the transcriptional phenotype of alveolar macrophages during aging. Except during acute injury when alveolar macrophage differentiation is incomplete, cellular ontogeny makes little difference in determining the transcriptional response of alveolar macrophages. Studies with parabiosis suggest the age-related changes in the alveolar microenvironment occur independently of circulating factors or cells. Our findings suggest that changes that target the microenvironment, for example metformin, senolytics or others might indirectly improve macrophage function during aging.
Project description:Our study shows that the aging lung microenvironment shapes the transcriptional phenotype of alveolar macrophages during aging. Except during acute injury when alveolar macrophage differentiation is incomplete, cellular ontogeny makes little difference in determining the transcriptional response of alveolar macrophages. Studies with parabiosis suggest the age-related changes in the alveolar microenvironment occur independently of circulating factors or cells. Our findings suggest that changes that target the microenvironment, for example metformin, senolytics or others might indirectly improve macrophage function during aging.