Project description:Leukemia inhibitory factor (LIF) is amongst the IL-6 family cytokines expressed in the lungs during pneumonia. However, the function of endogenous LIF during pneumonia has never been explored. The purpose of this study was to determine the transcriptional response to pneumonia in the lungs and whether or how this response is influenced by LIF. Mice received intratracheal instillations of vehicle (PBS) or Escherichia coli (10^6 CFU). Control IgG or anti-LIF specific IgG was included in the instillate. 24 hours after the challenge, lungs were collected for RNA isolation and microarray analysis.
Project description:Leukemia inhibitory factor (LIF) is amongst the IL-6 family cytokines expressed in the lungs during pneumonia. However, the function of endogenous LIF during pneumonia has never been explored. The purpose of this study was to determine the transcriptional response to pneumonia in the lungs and whether or how this response is influenced by LIF. Mice received intratracheal instillations of vehicle (PBS) or Escherichia coli (10^6 CFU). Control IgG or anti-LIF specific IgG was included in the instillate. 24 hours after the challenge, lungs were collected for RNA isolation and microarray analysis. RNA from 3 separate groups of mice (3 mice per group) was analyzed: 1) 24h Vehicle/control IgG-treated; 2) 24h E. coli/control IgG-treated; and 3) 24h E. coli/anti-LIF-specific IgG.
Project description:During bacterial pneumonia, alveolar epithelial cells are critical for maintaining gas exchange and providing antimicrobial as well as pro-immune properties. We previously demonstrated that leukemia inhibitory factor (LIF), an IL-6 family cytokine, is produced by type II alveolar epithelial cells (ATII) and is critical for tissue protection during bacterial pneumonia. However, the target cells and mechanisms of LIF-mediated protection remain unknown. Here, we demonstrate that antibody-induced LIF blockade remodels the lung epithelial transcriptome in association with increased apoptosis. Based on these data, we performed pneumonia studies using a novel mouse model in which LIFR (the unique receptor for LIF) is absent in lung epithelium. While LIFR was detected on the surface of epithelial cells, its absence only minimally contributed to tissue protection during pneumonia. Single-cell RNA-sequencing (scRNAseq) was conducted to identify adult murine lung cell types most prominently expressing LIFR, revealing endothelial cells, mesenchymal cells, and ATIIs as major sources of LIFR. Sequencing data indicated that ATII cells were significantly impacted as a result of pneumonia, with additional differences observed in response to LIF neutralization, including but not limited to gene programs related to cell death, injury, and inflammation. Overall, our data suggest that LIF signaling on epithelial cells alters responses in this cell type during pneumonia. However, our results also suggest separate and perhaps more prominent roles of LIFR in other cell types, such as endothelial cells or mesenchymal cells, which provide grounds for future investigation.
Project description:Oncostatin M (OSM) is an IL-6 family cytokine that is necessary for neutrophil recruitment in pneumonia by inducing STAT3-dependent production of CXCL5. We used microarrays to identify additional pathways affected by OSM neutralization in the lungs during pneumonia.
Project description:Leukemia inhibitory factor (LIF) is a cytoprotective cytokine that reduces lung injury during pneumonia. The purpose of this study was to determine the influence of LIF on pneumonia-induced gene changes in lung epithelium. Mice received intratracheal instillations of vehicle (PBS) or Escherichia coli (10^6 CFU). Control IgG or anti-LIF specific IgG was included in the instillate. 6 hours after the challenge, lung epithelial cells (EpCAM+/CD45-) were sorted from enzymatic lung digests and used for RNA isolation and microarray analysis.
Project description:Leukemia inhibitory factor (LIF) is a cytoprotective cytokine that reduces lung injury during pneumonia. The purpose of this study was to determine the influence of LIF on pneumonia-induced gene changes in lung epithelium. Mice received intratracheal instillations of vehicle (PBS) or Escherichia coli (10^6 CFU). Control IgG or anti-LIF specific IgG was included in the instillate. 24 hours after the challenge, lung epithelial cells (EpCAM+/CD45-) were sorted from enzymatic lung digests and used for RNA isolation and microarray analysis.
Project description:C57BL/6 mice were intratracheally challenged for 24 hours with saline or E. coli (1 x 10^6 CFU) with or without LIF neutralization. Left lobes were collected and digested into single-cell suspensions for FACS. Equal ratios of CD45+ (leukocytes), CD45-EpCAM+ (epithelium), and CD45-EpCAM- (other) cells were pooled from a mouse undergoing each condition.
