Clara cells drive eosinophil accumulation in allergic asthma

SS Sonar, M Ehmke, LM Marsh, J Dietze… - European …, 2012 - Eur Respiratory Soc
SS Sonar, M Ehmke, LM Marsh, J Dietze, JC Dudda, ML Conrad, H Renz, WA Nockher
European Respiratory Journal, 2012Eur Respiratory Soc
Development of allergic asthma is a complex process involving immune, neuronal and
tissue cells. In the lung, Clara cells represent a major part of the “immunomodulatory barrier”
of the airway epithelium. To understand the contribution of these cells to the inflammatory
outcome of asthma, disease development was assessed using an adjuvant-free ovalbumin
model. Mice were sensitised with subcutaneous injections of 10 μg endotoxin-free
ovalbumin in conjunction with naphthalene-induced Clara cell depletion. Clara epithelial …
Development of allergic asthma is a complex process involving immune, neuronal and tissue cells. In the lung, Clara cells represent a major part of the “immunomodulatory barrier” of the airway epithelium.
To understand the contribution of these cells to the inflammatory outcome of asthma, disease development was assessed using an adjuvant-free ovalbumin model. Mice were sensitised with subcutaneous injections of 10 μg endotoxin-free ovalbumin in conjunction with naphthalene-induced Clara cell depletion.
Clara epithelial cell depletion in the lung strongly reduced eosinophil influx, which correlated with decreased eotaxin levels and, moreover, diminished the T-helper cell type 2 inflammatory response, including interleukin (IL)-4, IL-5 and IL-13. In contrast, airway hyperresponsiveness was increased. Further investigation revealed Clara cells as the principal source of eotaxin in the lung.
These findings are the first to show that Clara airway epithelial cells substantially contribute to the infiltration of eotaxin-responsive CCR3+ immune cells and augment the allergic immune response in the lung. The present study identifies Clara cells as a potential therapeutic target in inflammatory lung diseases such as allergic asthma.
European Respiratory Society