Project description:Bovine respiratory epithelial cells have different susceptibility to bovine
respiratory syncytial virus infection. The cells derived from the lower
respiratory tract were significantly more susceptible to the virus than those
derived from the upper respiratory tract. Pre-infection with virus of lower
respiratory tract with increased adherence of P. multocida; this was not the
case for upper tract. However, the molecular mechanisms of enhanced
bacterial adherence are not completely understood. To investigate whether
virus infection regulates the cellular adherence receptor on bovine trachea-,
bronchus- and lung-epithelial cells, we performed proteomic analyses.
Project description:Exposure to cigarette smoke (CS) is etiologically linked to the development of fatal respiratory diseases, and there is a need to understand the mechanisms whereby CS causes damage. While animal models have provided valuable insights into smoking-related respiratory tract damage, modern toxicity testing calls for reliable in vitro models as alternatives for animal experimentation. Primary cells and immortalized cell lines can be used to gain some insight; however, the three-dimensional organotypic culture systems probably better mimic the morphological, physiological, and molecular attributes of the human respiratory tract. Even though the bronchus, bronchioles, and lung parenchyma are the primary sites of smoking-related respiratory disease manifestation, the nasal epithelium has been proposed as a surrogate tissue to study the effects of smoking on the respiratory tract. Here, we report on a repeated whole mainstream CS exposure of nasal and bronchial organotypic tissue cultures from which transcriptomic data were collected at several post-exposure time points. Despite the remarkably similar histology and cellular response to whole CS in both tissue types, as measured by cellular staining and cytokine secretion assessment, transcriptomic analyses combined with quantitative biological network modeling identified biological mechanisms that were unique to bronchial tissue at late post-exposure time points. Organotypic models therefore appear to be a promising alternative to animal experimentation, and provide species-relevant insights into the effects of CS exposure on the respiratory system.
Project description:Lower respiratory tract infections are among the top five leading causes of human death. Fighting these infections is therefore a world health priority. Searching for induced alterations in host gene expression shared by several relevant respiratory pathogens represent an alternative to identifying new targets for wide-range host-oriented therapeutics. With this aim, alveolar macrophages were independently infected with three unrelated bacterial (Streptococcus pneumoniae, Klebsiella pneumoniae and Staphylococcus aureus) and two dissimilar viral (respiratory syncytial virus and influenza A virus) respiratory pathogens which are nevertheless highly relevant for human health. Cells were also activated with bacterial lipopolysaccharide (LPS) as a prototypical pathogen-associated molecular pattern. Patterns of differentially expressed cellular genes shared by the indicated pathogens were searched by microarray analysis. Most of the commonly up-regulated genes were related to the innate immune response and/or apoptosis, with Toll-like, RIG-I-like and NOD-like receptors among the top ten signaling pathways with over-expressed genes. These results identify new potential broad-spectrum targets to fight the important human infections caused by the bacteria and viruses studied here.
2017-03-01 | GSE88825 | GEO
Project description:Study on pathogen diversity of patients with respiratory tract infection
Project description:<p>Accurate tests for microbiologic diagnosis of lower respiratory tract infections (LRTI) are needed. Gene expression profiling of whole blood represents a powerful new approach for analysis of the host response during respiratory infection that can be used to supplement pathogen detection testing. Using qPCR, we prospectively validated the differential expression of 10 genes previously shown to discriminate bacterial and non-bacterial LRTI confirming the utility of this approach. In addition, a novel approach using RNAseq analysis identified 141 genes differentially expressed in LRTI subjects with bacterial infection. Using "pathway-informed" dimension reduction, we identified a novel 11 gene set (selected from lymphocyte, α-linoleic acid metabolism, and IGF regulation pathways) and demonstrated a predictive accuracy for bacterial LRTI (nested CV-AUC=0.87). RNAseq represents a new and an unbiased tool to evaluate host gene expression for the diagnosis of LRTI.</p>
Project description:Infectious bronchitis virus (IBV), is a coronavirus which infects chickens (Gallus gallus), and is one of the foremost causes of economic loss within the poultry industry, affecting the performance of both meat-type and egg-laying birds. The virus replicates not only in the epithelium of upper and lower respiratory tract tissues, but also in many tissues along the alimentary tract and elsewhere e.g. kidney, oviduct and testes. It can be detected in both respiratory and faecal material. There is increasing evidence that IBV can infect species of bird other than the chicken. Interestingly breeds of chicken vary with respect to the severity of infection with IBV, which may be related to the immune response (Cavanagh, 2006). Here we examine differential expression of genes in the trachea of susceptible and resistant birds, in order to identify genes which may be involved in resistance to IBV.
Project description:Rhinoviruses (RV) have been shown to inhibit subsequent infection by heterologous respiratory viruses, including influenza viruses and severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). To better understand the mechanisms whereby RV protects against pulmonary coronavirus infection, we used a native murine virus, mouse hepatitis virus strain 1 (MHV-1), that causes severe disease in the lungs of infected mice. We found that priming of the respiratory tract with RV completely prevented mortality and reduced morbidity of a lethal MHV-1 infection. Replication of MHV-1 was reduced in RV-primed mouse lungs although type I interferon (IFN-b) expression was more robust in mice infected with MHV-1 alone. We further showed that type I IFN signaling was required for survival of mice given a non-lethal dose of MHV-1. RV-primed mice had reduced pulmonary inflammation and hemorrhage and influx of leukocytes, especially neutrophils, in the airways. RV-mediated priming in the respiratory tract protects against a lethal pulmonary coronavirus infection in mice. This model can be used to understand how heterologous viruses impact each other during coinfection of the respiratory tract.