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Background: Cilomilast, a phosphodiesterase-4 (PDE4) selective inhibitor, has anti-inflammatory effects in vitro and in vivo and reduces COPD exacerbations. We tested the hypothesis that cilomilast inhibits virus-induced airway epithelial intercellular adhesion molecule-1 (ICAM-1) expression and inflammatory cytokine/chemoattractants, IL-6, CXCL8, and CCL5 production in vitro. Methods: BEAS-2B bronchial epithelial cells were incubated with 0.5–2 MOI (multiplicity of infection–infectious units/cell) of rhinovirus 16 (RV16). Then, 0.1–10 μM cilomilast or 10 nM dexamethasone, as inhibition control, were added pre- or post-1 h RV16 infection. Supernatant and cells were sampled at 8, 24, 48, and 72 h after infection. Cell surface ICAM-1 expression was detected by immunogold labelling and visualised by high-resolution scanning electron microscopy (HR-SEM), while IL-6, CXCL8, and CCL5 protein release and mRNA expression were measured using an ELISA and RT-PCR. Results: Cilomilast significantly decreased RV16-induced ICAM-1 expression to approximately 45% (p < 0.01). CXCL8 protein/mRNA production was reduced by about 41% (p < 0.05), whereas IL-6 protein/mRNA production was increased to between 41–81% (p < 0.001). There was a trend to reduction by cilomilast of RV16-induced CCL5. Conclusions: Cilomilast has differential effects on RV16-induced ICAM-1 and interleukins, inhibiting virus-induced ICAM-1 expression and CXCL8 while increasing IL-6 production. These in vitro effects may help to explain the beneficial actions of this PDE4 inhibitor in vivo. [ABSTRACT FROM AUTHOR]

Author(s): Marco Contoli [1, 2, 6]; Simon D Message [1, 6]; Vasile Laza-Stanca [1]; Michael R Edwards [1]; Peter A B Wark [1, 3]; Nathan W Bartlett [1]; Tatiana Kebadze [...]

We showed that the expression of CRTH2 and IL-4 on Treg cells is higher in asthmatic individuals compared to controls (Figure 2A). T regulatory cells from atopic asthmatic individuals show a Th2-like phenotype However, under certain conditions, Treg cells can display a pathogenic and proinflammatory phenotype and contribute to disease pathogenesis.2 Treg cells of food allergic children showed a T helper 2 (Th2)-like phenotype. [Extracted from the article]

Abstract Background Acute exacerbations of COPD are a major cause of morbidity, mortality and hospitalisation. Respiratory viruses are associated with the majority of exacerbations but a causal relationship has not been demonstrated and the mechanisms of virus-induced exacerbations are poorly understood. Development of a human experimental model would provide evidence of causation and would greatly facilitate understanding mechanisms, but no such model exists. Methods We aimed to evaluate the feasibility of developing an experimental model of rhinovirus induced COPD exacerbations and to assess safety of rhinovirus infection in COPD patients. We carried out a pilot virus dose escalating study to assess the minimum dose of rhinovirus 16 required to induce experimental rhinovirus infection in subjects with COPD (GOLD stage II). Outcomes were assessed by monitoring of upper and lower respiratory tract symptoms, lung function, and virus replication and inflammatory responses in nasal lavage. Results All 4 subjects developed symptomatic colds with the lowest dose of virus tested, associated with evidence of viral replication and increased pro-inflammatory cytokines in nasal lavage. These were accompanied by significant increases in lower respiratory tract symptoms and reductions in PEF and FEV1. There were no severe exacerbations or other adverse events. Conclusion Low dose experimental rhinovirus infection in patients with COPD induces symptoms and lung function changes typical of an acute exacerbation of COPD, appears safe, and provides preliminary evidence of causation.

The article discusses a study that determined the association and response of bronchial mucosal inflammation with clinical and physiologic outcomes of exacerbations in rhinovirus-inducd asthma. Immunohistochemistry methods were used for detecting inflammatory cell phenotypes that infiltrate bronchial mucosa. Results showed significant increase in neutrophils, subepithelial and epithelial cells with rhinovirus infection at baseline along with higher monocyte/macrophage infiltration.