Project description:We performed comparative transcriptomic analysis of the outer membrane vesicles (OMVs) released from B. burgdorferi. We identified a total of ~1200 unique transcripts with at least one mapped read from the bacterial cell and its OMVs.
Project description:Elexacaftor/tezacaftor/ivacaftor (ETI, Trikafta) is highly effective treatment for many cystic fibrosis patients, at least partly because it increases CFTR mediated Cl- and HCO3- secretion by airway epithelial cells leading to improved lung function and less frequent exacerbations and hospitalizations. However, little is known about how ETI affects airway epithelial cells in ways not related to CFTR mediated Cl- and HCO3- secretion, for example how ETI affects the expression of genes other than CFTR or how ETI might affect airway cells’ response to infection. It is established that CF airway cells bearing the delta F 508 mutation the CFTR gene respond characteristically differently from wild type CFTR cells, and we hypothesized that, as a highly effective CFTR modulator, ETI might make airway cells from CF donors respond to pathogen stimulation (Pseudomonas aeruginosa PA14 or outer membrane vesicles isolated from these bacteria) in more the same way that cells from wild type, healthy control cells do. We tested this hypothesis by measuring gene expression responses in polarized primary CF airway cells exposed to ETI alone or ETI in the presence of a pathogen challenge (PA14 or outer membrane vesicles). Responses of CFTR wild type primary CF airway cells to PA14 or outer membrane vesicles was also measured for comparison
Project description:Asthma is the most common chronic respiratory disease. Asthma that cannot be well controlled by steroid treatment is called steroid-resistant asthma. Steroid-resistant asthma accounts for only 5% of all asthma cases, but it accounts for 80% of asthma healthcare costs. Nontypeable Haemophilus influenzae (NTHi), as a Gram-negative bacterium, can release outer membrane vesicles (OMVs) and transfer biomolecules to host cells and the external environment by carrying lipopolysaccharides, proteins, peptidoglycans, outer membrane proteins, cell wall components, proteins, nucleic acids, ion metabolites, and signaling molecules. Thus, it plays a role in obtaining nutrition, stress, toxin delivery, adhesion, host immune surveillance evasion, and host immune response regulation. It becomes an essential way in bacterial pathogenesis. To further clarify whether NTHi OMVs could be inhaled to induce steroid-resistant asthma, we isolated and purified NTHi OMVs. In vivo experiments showed that NTHi OMVs could be inhaled and enter airway epithelial cells. Cosensitization with OVA induces steroid-resistant asthma in mice. Furthermore, through high-throughput sequencing, we found that the NTHi OMVs and OVA co-sensitized mice had significantly enriched inflammatory and immune-related signaling pathways, and the transcription and secretion of IL-1β were increased was the potential cause of SRA.
Project description:Carbapenem-resistant Acinetobacter baumannii (CRAB) is a critical nosocomial pathogen with limited treatment options. Although antibiotic resistance in CRAB is well-characterized, its interactions with host immunity and the contribution of outer membrane vesicles (OMVs) to pathogenesis remain poorly understood. We examined a clinical CRAB isolate and compared it with the reference strain A19606. Antimicrobial susceptibility testing revealed complete resistance of CRAB to commonly used antibiotics in clinical practice, while A19606 remained susceptible to most agents. In murine intranasal infection models and bone marrow-derived macrophages, CRAB induced significantly stronger activation of inflammatory signaling pathways and elevated levels of pro-inflammatory cytokines relative to A19606. Transcriptomic analysis of infected lung tissue identified differentially expressed genes, enriched for inflammatory response pathways. proteomics showed upregulated proteins in CRAB related to secretion systems. OMVs characterization revealed that CRAB-derived OMVs highly enriched in proteins associated with periplasmic and outer membrane spaces, and more potent in triggering macrophage inflammatory signaling. CRAB displays expansive antibiotic resistance and enhanced pro-inflammatory potential mediated in part by unique OMVs properties. Targeting OMVs formation or host immune modulation may represent effective strategies for combating CRAB infections.