SELECTED ARTICLES FROM THE RECENT LITERATURE 2006

12/21/06

Another inflammatory stimulus in asthma?

Summary
Background – It is now generally agreed that an eosinophil-rich bronchial inflammation characterizes most cases of persistent asthma (PA). Therefore, there has been considerable investigation of the factors which attract leukocytes from the blood into the bronchial wall.

Findings – Gwinn et al described studies of cyclophilins (C-phil) ubiquitously distributed intracellular proteins which can also be secreted into the extra-cellular milieu. C-phil act as chemoattractants for eosinophils and CD4+ lymphocytes which express a receptor called CD 147 on their surface.

Using a murine model of experimental allergic asthma they found; 1) increased levels of C-phil in the airways of asthmatic mice; 2) the expression of CD147 is increased on eosinophils and CD4+ lymphocytes in the bronchial walls of such mice; 3) treatment of such mice with an anti-CD147 blocking antibody reduces the accumulation of eosinophils and CD4+ cells in the bronchial wall by up to 50%; 4) anti-CD147 treatment also reduced epithelial mucin production and bronchial reactivity to inhaled methacholine.

Reference
J Immunology 2006;177:4870-4879

Editor's Comments
The major emphasis on attractants for the inflammatory cell responses in asthma has recently centered on chemotaxins such as eotoxin. The findings described above suggest that another class of compounds may also play a pathogenic role in asthmatic inflammation, at least as seen in this experimental asthma model. It remains to be seen whether analogous findings are present in humans with PA.

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