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Lung Compartment (lung + compartment)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Elemental signals regulating eosinophil accumulation in the lung

IMMUNOLOGICAL REVIEWS, Issue 1 2001
Paul S. Foster
Summary: In this review we identify the elemental signals that regulate eosinophil accumulation in the allergic lung. We show that there are two interwoven mechanisms for the accumulation of eosinophils in pulmonary tissues and that these mechanisms are linked to the development of airways hyperreactivity (AHR). Interleukin-(IL)-5 plays a critical role in the expansion of eosinophil pools in both the bone marrow and blood in response to allergen provocation of the airways. Secondly, IL-4 and IL-13 operate within the allergic lung to control the transmigration of eosinophils across the vascular bed into pulmonary tissues. This process exclusively promotes tissue accumulation of eosinophils. IL-13 and IL-4 probably act by activating eosinophil-specific adhesion pathways and by regulating the production of IL-5 and eotaxin in the lung compartment. IL-5 and eotaxin co-operate locally in pulmonary tissues to selectively and synergistically promote eosinophilia. Thus, IL-5 acts systemically to induce eosinophilia and within tissues to promote local chemotactic signals. Regulation of IL-5 and eotaxin levels within the lung by IL-4 and IL-13 allows Th2 cells to elegantly co-ordinate tissue and peripheral eosinophilia. Whilst the inhibition of either the IL-4/IL-13 or IL-5/ eotaxin pathways resulted in the abolition of tissue eosinophils and AHR, only depletion of IL-5 and eotaxin concurrently results in marked attenuation of pulmonary inflammation. These data highlight the importance of targeting both IL-5 and CCR3 signalling systems for the resolution of inflammation and AHR associated with asthma. S.M. is a Postdoctoral Fellow funded by a grant from the Human Frontiers Foundation to P.S.F. and M.E.R. J.M. is supported by the German Research Association (grant MA 2241/1-1) and S.P.H by a NH&MRC CJ Martin Postdoctoral Fellowship. [source]

The small airways and distal lung compartment in asthma and COPD: a time for reappraisal

ALLERGY, Issue 2 2010
M. Contoli
To cite this article: Contoli M, Bousquet J, Fabbri LM, Magnussen H, Rabe KF, Siafakas NM, Hamid Q, Kraft M. The small airways and distal lung compartment in asthma and COPD: a time for reappraisal. Allergy 2010; 65: 141,151. Abstract The involvement of small airways in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD) has been debated for a long time. However, a proper definition of small airway disease is still lacking, and neither a widely accepted biomarker nor a functional parameter to assess small airway abnormalities and to explore the effect of tested compounds on small airways is available. Aiming towards increased knowledge and consensus on this topic, this perspective paper intends to (i) strengthen awareness among the scientific community on the role of small airways in asthma and COPD; (ii) examine the pros and cons of some biological, functional and imaging parameters in the assessment of small airway abnormalities; and (iii) discuss the evidence for distal airway pharmacological targeting in asthma and COPD. [source]

Inflammatory cell mapping of the respiratory tract in fatal asthma

CLINICAL & EXPERIMENTAL ALLERGY, Issue 5 2005
S. De Magalhães Simões
Summary Background The site and distribution of inflammation in the airways of asthmatic patients has been largely investigated. Inflammatory cells are distributed in both large and small airways in asthma. It has been demonstrated that distal lung inflammation in asthma may significantly contribute to the pathophysiology of the disease. The upper airways have also been implicated in the overall asthmatic inflammation. Although it is now accepted that lung inflammation is not restricted to the intrapulmonary airways in asthma, little is known about cell distribution in the other lung compartments and their relation to the intrapulmonary airways. Objective We aimed to map the inflammatory process in fatal asthma (FA), from the upper airways to the lung parenchyma. Methods Eosinophil, neutrophil, mast cell and lymphocyte content were determined in nasal mucosa, the trachea, intrapulmonary airways and parenchyma (peribronchiolar and distal) of 20 patients with FA and 10 controls. Results Eosinophil content was higher in all studied areas in FA compared with controls (P<0.02). Mast cell content was higher in the outer area of larger airways, small membranous bronchioles and in peribronchiolar parenchyma of FA compared with controls (P<0.04). CD3+, CD4+and CD20+cells showed increased content in FA intrapulmonary airways compared with controls (P<0.05). There was a positive correlation between CD4+cell content in nasal mucosa and larger airways in asthmatics. Increased neutrophil content was observed only in peribronchiolar parenchyma of FA (P=0.028). Conclusion Eosinophils present a widespread distribution within the respiratory tract in FA, from the nasal mucosa to the distal lung. The outer wall of small membranous bronchioles is the main site of inflammatory changes in FA. There is a localized distribution of alveolar inflammation at the peribronchiolar region for mast cells and neutrophils. Our findings provide further evidence of the importance of the lung periphery in the pathophysiology of FA. [source]