Can we make sense out of cytokines?

Cytokines and inflammatory mediators in cystic fibrosis

Airway disease in cystic fibrosis (CF) is characterised by a continuous cycle of chronic infection and inflammation dominated by a neutrophilic infiltrate. This inflammation is characterised by an increased production of pro-inflammatory cytokines in the lung. The relationship between the abnormal CFTR gene product and the development of inflammation and progression of lung disease in CF is not fully understood. This review article studied the mechanisms of pulmonary inflammation in CF, the profiles of cytokines and inflammatory mediators in the lung in CF, the mechanisms that predispose to chronic Pseudomonas aeruginosa infection, cytokine involvement in diseases other than CF and reviewed current therapeutic strategies for CF. Imbalances of cytokine secretion are now better understood due to recent advances in understanding CF at a molecular level and it is increasingly thought that the normal inflammatory process is deranged in CF early in the course of the disease and may occur in the absence of detectable infection. However, the relationship between this unbalanced cytokine production, the mutations in CFTR and its actual consequence for pathogenesis need further investigation.

Adenovirus-mediated transfer of heme oxygenase-1 cDNA attenuates severe lung injury induced by the influenza virus in mice

Heme oxygenase-1 (HO-1) is an inducible heat shock protein that regulates heme metabolism to form bilirubin, ferritin and carbon monoxide. Based on recent evidence that HO-1 is involved in the resolution of inflammation by modulating apoptotic cell death or cytokine expression, the present study examined whether overexpression of exogenous HO-1 gene transfer provides a therapeutic effect on a murine model of acute lung injury caused by the type A influenza virus. We demonstrate herein that the transfer of HO-1 cDNA resulted in (1) suppression of both pathological changes and intrapulmonary hemorrhage; (2) enhanced survival of animals; and (3) a decrease of inflammatory cells in the lung. TUNEL analysis revealed that HO-1 gene transfer reduced the number of respiratory epithelial cells with DNA damage, and caspase assay suggested that HO-1 suppressed lung injury via a caspase-8-mediated pathway. These findings suggest the feasibility of HO-1 gene transfer to treat lung injury induced by a pathogen commonly seen in the clinical setting. Since oxidative stress and lung injury are involved in many lung disorders, such as pneumonia induced by a variety of microorganisms and pulmonary fibrosis, HO-1 may be useful for wider clinical applications in gene therapy targeting lung disorders including acute pneumonia and pulmonary fibrosis.