Redox-dependent thiol modifications: implications for the release of extracellular vesicles.

Extracellular vesicles (EVs), including microvesicles and exosomes, are emerging as important regulators of homeostasis and pathophysiology. During pro-inflammatory and pro-oxidant conditions, EV release is induced. As EVs released under such conditions often exert pro-inflammatory and procoagulant effects, they may actively promote the pathogenesis of chronic diseases.

Immunomodulatory role for membrane vesicles released by THP-1 macrophages and respiratory pathogens during macrophage infection.

Background: During infection, inflammation is partially driven by the release of mediators which facilitate intercellular communication. Amongst these mediators are small membrane vesicles (MVs) that can be released by both host cells and Gram-negative and -positive bacteria. Bacterial membrane vesicles are known to exert immuno-modulatory and -stimulatory actions.

Ultrafiltration combined with size exclusion chromatography efficiently isolates extracellular vesicles from cell culture media for compositional and functional studies.

Appropriate isolation methods are essential for unravelling the relative contribution of extracellular vesicles (EVs) and the EV-free secretome to homeostasis and disease. We hypothesized that ultrafiltration followed by size exclusion chromatography (UF-SEC) provides well-matched concentrates of EVs and free secreted molecules for proteomic and functional studies. Conditioned media of BEAS-2B bronchial epithelial cells were concentrated on 10 kDa centrifuge filters, followed by separation of EVs and free protein using sepharose CL-4B SEC.

Budesonide, fluticasone propionate, and azithromycin do not modulate the membrane vesicle release by THP-1 macrophages and respiratory pathogens during macrophage infection.

Patients with more severe chronic obstructive pulmonary disease frequently experience exacerbations and it is estimated that up to 50% of these exacerbations are associated with bacterial infections. The mainstay treatment for these infection-related exacerbations constitutes the administration of glucocorticoids, alone or in combination with antibiotics. A recent line of evidence demonstrates that many hormones including the steroid beclomethasone can also directly affect bacterial growth, virulence, and antibiotic resistance.

Exposure to common respiratory bacteria alters the airway epithelial response to subsequent viral infection.

Background: Colonization of the airways with potential pathogenic bacteria is observed in a number of chronic respiratory diseases, such as COPD or cystic fibrosis. Infections with respiratory viruses are known triggers of exacerbations of these diseases. We here investigated if pre-exposure to bacteria alters the response of lung epithelial cells to subsequent viral infection.

Haemophilus influenzae increases the susceptibility and inflammatory response of airway epithelial cells to viral infections.

Nontypeable Haemophilus influenzae (NTHI), a common colonizer of lungs of patients with chronic obstructive pulmonary disease (COPD), can enhance expression of the cellular receptor intercellular adhesion molecule 1 (ICAM-1), which in turn can be used by major group human rhinoviruses (HRVs) for attachment. Here, we evaluated the effect of NTHI-induced up-regulation of ICAM-1 on viral replication and inflammatory responses toward different respiratory viruses. Therefore, human bronchial epithelial cells were pretreated with heat-inactivated NTHI (hi-NTHI) and subsequently infected with either HRV16 (major group), HRV1B (minor group), or respiratory syncytial virus (RSV).