ABSTRACT: Gene expression profiling of neutrophils and whole lung tissue from wildtype and Nrf2 null (Nfe2l2-/-) mice during S. pneumoniae pneumonia [whole lung]
Project description:The transcription factor Nrf2 (gene symbol Nfe2l2) regulates the transcriptional response to oxidative stress and plays a critical protective role in the lungs. These studies tested the role of Nrf2 during pneumonia induced by Streptococcus pneumoniae (SP) at 24 hours in mice and identified Nrf2-dependent genes and pathways in lung tissue and in recruited neutrophils.
Project description:The transcription factor Nrf2 (gene symbol Nfe2l2) regulates the transcriptional response to oxidative stress and plays a critical protective role in the lungs. These studies tested the role of Nrf2 during pneumonia induced by Streptococcus pneumoniae (SP) at 24 hours in mice and identified Nrf2-dependent genes and pathways in lung tissue and in recruited neutrophils.
Project description:Gene expression profiling of neutrophils and whole lung tissue from wildtype and Nrf2 null (Nfe2l2-/-) mice during S. pneumoniae pneumonia [neutrophils]
Project description:Gene expression profiling of neutrophils and whole lung tissue from wildtype and Nrf2 null (Nfe2l2-/-) mice during S. pneumoniae pneumonia
Project description:These studies profiled the expression of mRNAs and microRNAs (miRs) in lung neutrophils in WT mice during S. pneumoniae pneumonia and performed in depth in silico analyses. Lung neutrophils were isolated 24 hours after intratracheal instillation of PBS or S. pneumoniae, and mRNAs and miRs differentially expressed (DE) between S. pneumoniae- and PBS-treated samples were identified using microarrays.
Project description:These studies profiled the expression of mRNAs and microRNAs (miRs) in lung neutrophils in WT mice during S. pneumoniae pneumonia and performed in depth in silico analyses. Lung neutrophils were isolated 24 hours after intratracheal instillation of PBS or S. pneumoniae, and mRNAs and miRs differentially expressed (DE) between S. pneumoniae- and PBS-treated samples were identified using microarrays.
Project description:Streptococcus pneumoniae is a leading cause of community-acquired pneumonia. Intercellular adhesion molecule-1 (ICAM-1) is an adhesion molecule that is highly expressed on the pulmonary capillary endothelium, alveolar epithelium and other cell types within the lung. ICAM-1 is known to play important roles in leukocyte adhesion, migration, and motility. To determine the contributions of ICAM-1 to bacterial clearance and leukocyte kinetics during pneumonia, mice were inoculated with S. pneumoniae and evaluated 1, 4 and 7 days later. Our results show that Icam1-/- mice have a greater number of viable bacteria within the lung at each time point. The impaired clearance observed in Icam1-/- mice was not due to an impediment in leukocyte recruitment. In fact, Icam1-/- mice had a greater number of neutrophils and recruited inflammatory macrophages in the lung tissue and the alveoli/airways on day 7. In contrast, fewer alveolar macrophages were present in the BAL of Icam1-/- mice. The loss of body weight and the concentrations of inflammatory mediators in the BAL were also significantly greater in Icam1-/- mice. Mechanistic studies to understand the defect in clearance show that neutrophils and macrophage subpopulations had no defect in phagocytosis or acidification of phagosomes. RNA sequencing reveals many differences in gene expression, but does not suggest° a defect in phagocytosis. Thus, ICAM-1 is necessary for the clearance of S. pneumoniae and for the resolution of pneumonia, but is not required for the recruitment of neutrophils or inflammatory macrophages into the pneumonic lung parenchyma or the alveoli/airways during S. pneumoniae-induced pneumonia.
Project description:Streptococcus (S.) pneumoniae is the most frequently isolated causative pathogen community-acquired pneumonia, a leading cause of mortality worldwide. We investigated the role of the inflammasome sensor NLRP3 and the inflammasome adapter ASC during S. pneumoniae pneumonia. Detailed analysis of the early inflammatory response in the lung by whole genome transcriptional profiling, we identified several mediators that were differentially expressed between Nlrp3-/- and Asc-/ - mice.
Project description:Streptococcus (S.) pneumoniae is the most frequently isolated causative pathogen community-acquired pneumonia, a leading cause of mortality worldwide. We investigated the role of the inflammasome sensor NLRP3 and the inflammasome adapter ASC during S. pneumoniae pneumonia. Detailed analysis of the early inflammatory response in the lung by whole genome transcriptional profiling, we identified several mediators that were differentially expressed between Nlrp3-/- and Asc-/ - mice. WT, Nlrp3- and Asc-deficient mice were intranasally inocculated with Streptococcus pneumoniae D39 and ATCC6303 both at high and low dose. Lung homogenates were harvested and gene expression profiling was performed.
Project description:Pneumococcal pneumonia is a leading cause of death and a major source of human morbidity. The initial immune response plays a central role in determining the course and outcome of pneumococcal disease. We combine bacterial titer measurements from mice infected with Streptococcus pneumoniae with mathematical modeling to investigate the coordination of immune responses and the effects of initial inoculum on outcome. To evaluate the contributions of individual components, we systematically build a mathematical model from three subsystems that describe the succession of defensive cells in the lung: resident alveolar macrophages, neutrophils and monocyte-derived macrophages. The alveolar macrophage response, which can be modeled by a single differential equation, can by itself rapidly clear small initial numbers of pneumococci. Extending the model to include the neutrophil response required additional equations for recruitment cytokines and host cell status and damage. With these dynamics, two outcomes can be predicted: bacterial clearance or sustained bacterial growth. Finally, a model including monocyte-derived macrophage recruitment by neutrophils suggests that sustained bacterial growth is possible even in their presence. Our model quantifies the contributions of cytotoxicity and immune-mediated damage in pneumococcal pathogenesis.
