Distinct expression of RANTES and GM-CSF by lipopolysaccharide in human nasal fibroblasts but not in other airway fibroblasts.

Eosinophil infiltration of tissue is a hallmark of nasal polyposis and asthma in both atopic and nonatopic patients. Structural cells like airway fibroblasts are a rich source of cytokines and inflammatory mediators. In order to verify whether airway fibroblasts play a role in eosinophilic infiltration, we investigated the release of eosinophil chemotactic and activating factors from airway fibroblasts when stimulated with nonallergenic exogenous agents such as endotoxin (lipopolysaccharide; LPS). Using a number of primary human airway tissue-derived fibroblast lines, we demonstrated that LPS could induce the gene expression and production of RANTES (regulated and normal T cell expressed and presumably secreted) and granulocyte/macrophage colony-stimulating factor (GM-CSF) only in nasal but not in pharyngeal, tracheal, bronchial, and lung fibroblasts. This selective responsiveness of nasal fibroblasts to LPS was time and dose dependent. These findings suggest that nasal fibroblasts may play an important role in the recruitment and activation of eosinophils into nasal polyps through the release of RANTES and GM-CSF.