A Promoter Polymorphism in the CD59 Complement Regulatory Protein Gene in Donor Lungs Correlates With a Higher Risk for Chronic Rejection After Lung Transplantation.

Complement activation leads primarily to membrane attack complex formation and subsequent target cell lysis. Protection against self-damage is regulated by complement regulatory proteins, including CD46, CD55, and CD59. Within their promoter regions, single-nucleotide polymorphisms (SNPs) are present that could influence transcription. We analyzed these SNPs and investigated their influence on protein expression levels. A single SNP configuration in the promoter region of CD59 was found correlating with lower CD59 expression on lung endothelial cells (p = 0.016) and monocytes (p = 0.013). Lung endothelial cells with this SNP configuration secreted more profibrotic cytokine IL-6 (p = 0.047) and fibroblast growth factor ß (p = 0.036) on exposure to sublytic complement activation than cells with the opposing configuration, whereas monocytes were more susceptible to antibody-mediated complement lysis (p < 0.0001). Analysis of 137 lung transplant donors indicated that this CD59 SNP configuration correlates with impaired long-term survival (p = 0.094) and a significantly higher incidence of bronchiolitis obliterans syndrome (p = 0.046) in the recipient. These findings support a role for complement in the pathogenesis of this posttransplant complication and are the first to show a deleterious association of a donor CD59 promoter polymorphism in lung transplantation.

Steroids induce a disequilibrium of secreted interleukin-1 receptor antagonist and interleukin-1ß synthesis by human neutrophils.

Chronic obstructive pulmonary disease (COPD) is characterised by neutrophilic inflammation in the airways and these neutrophils contribute to the production of inflammatory mediators. Dampening the production of proinflammatory mediators might be an important strategy to treat COPD and glucocorticosteroids are known to do so via inhibition of nuclear factor-κB. However, this pathway is important for the control of pro- and anti-inflammatory genes. We studied the effects of dexamethasone on production and secretion of pro-inflammatory interleukin (IL)-1ß and anti-inflammatory secreted IL-1 receptor antagonist (sIL-1Ra) by human neutrophils activated with tumor necrosis factor (TNF)-α. In vitro, TNF-α-stimulated neutrophils produced significant amounts of IL-1ß and sIL-1Ra; this production was inhibited by dexamethasone. However, synthesis and secretion of sIL-1Ra was inhibited at lower concentrations dexamethasone compared to IL-1ß, which changed the IL-1ß:sIL-1Ra ratio significantly. This altered ratio resulted in a more pro-inflammatory condition, as visualised by increased intercellular adhesion molecule-1 expression on human endothelial cells. In vivo, moderate-to-severe COPD patients using inhaled glucocorticosteroids have decreased plasma sIL-Ra levels compared with mild-to-moderate patients not on glucocorticosteroid treatment. In conclusion, dexamethasone induces a pro-inflammatory shift in the IL-1ß:sIL-1Ra cytokine balance in neutrophils in vitro, which might contribute to a lack of endogenous anti-inflammatory signals to dampen inflammation in vivo.

Systemic inflammation in COPD visualised by gene profiling in peripheral blood neutrophils.

BACKGROUND: The inflammatory process in chronic obstructive pulmonary disease (COPD) is characterised by the presence of neutrophils in the lung that are able to synthesise de novo several inflammatory mediators. The local chronic persistent inflammatory response is accompanied by systemic effects such as cytokine induced priming of peripheral leucocytes and muscle wasting. The preactivation or priming of peripheral blood neutrophils was used to gain more insight into the mechanisms of this systemic inflammatory response. METHODS: Gene arrays were performed on peripheral blood neutrophils obtained from healthy donors after stimulation in vitro with tumour necrosis factor (TNF)-alpha, granulocyte-macrophage colony stimulating factor (GM-CSF), or both. The expression of many inflammatory genes was regulated in these cells following stimulation. The expression of inflammatory genes in peripheral blood neutrophils in healthy subjects and those with COPD was measured by real time RT-PCR after stimulation with TNFalpha, GM-CSF, interleukin (IL)-8, fMLP, TNFalpha + GM-CSF, and lipopolysaccharide (LPS). RESULTS: The genes regulated in the gene array with TNFalpha/GM-CSF stimulated neutrophils included cytokines (such as IL-1beta), chemokines (such as IL-8), and adhesion molecules (such as ICAM-1). Disease severity as measured by forced expiratory volume in 1 second (FEV(1)) in COPD patients correlated with expression of several of these genes including IL-1beta (r = -0.540; p = 0.008), MIP-1beta (r = -0.583; p = 0.003), CD83 (r = -0.514; p = 0.012), IL-1 receptor 2 (r = -0.546; p = 0.007), and IL-1 receptor antagonist (r = -0.612; p = 0.002). CONCLUSIONS: These data are consistent with the hypothesis that progression of COPD is associated with the activation of neutrophils in the systemic compartment. De novo expression of inflammatory mediators by peripheral blood neutrophils suggests a pro-inflammatory role for these cells in the pathogenesis of COPD.

Systemic inflammation in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is characterised by a chronic inflammation in the pulmonary tissue. The disease is associated with a switch from a self-limiting inflammatory response, mainly initiated by smoke inhalation, to a chronic persistent inflammatory response after prolonged interaction with cigarette smoke. The extent of the inflammatory reaction is correlated with the severity of the disease. Chronic inflammation in the pulmonary tissue is also associated with systemic effects. These effects range from cytokine-induced priming of peripheral leukocytes, to muscle wasting induced by cytokines such as tumour necrosis factor-alpha. Despite a general consensus that chronic inflammation is a characteristic phenomenon of the disease, surprisingly little is known regarding the underlying pathogenetic mechanisms. A clear communication is present between the disease mechanisms in the pulmonary compartment and peripheral tissues, leading to the concept of COPD as a systemic inflammatory disease. This communication can be mediated by: 1) leakage of reactive oxygen species and stress-induced cytokines directly into the peripheral blood, 2) (pre)activation of peripheral blood leukocytes that can result in aberrant homing and activation of inflammatory cells in distant tissues, and 3) the liberation of proinflammatory mediators by leukocytes and/or stromal cells present in the pulmonary tissues during progression of the disease. The current authors hypothesise that the occurrence of a chronic inflammatory response after prolonged interaction of the pulmonary tissue with cigarette smoke causes aberrant homing of leukocytes to the tissue and delayed apoptosis. This leads to the autonomous characteristic of the inflammatory response in patients with chronic obstructive pulmonary disease.