Detection of eosinophilic-chemotactic RANTES in nasal turbinates in allergic rhinitis

The selective accumulation of eosinophils in the nasal mucosa is a feature of allergic rhinitis. The reasons are still unknown. Chemotaxins play an important role in the leukocyte tissue immigration of chronic inflammatory processes. Chemokines include heparin-binding proteins, of which RANTES shows selective chemotactic activity for eosinophils and memory T-lymphocytes but not neutrophils. Therefore we addressed the question whether nasal turbinates of patients with allergic rhinitis contain chemotactic activity for eosinophils. Protein fractions were extracted from tissue of nasal inferior turbinates using fluid nitrogen, citrate buffer (pH 2.5) and ultrasound homogenization. Chemotactic activity for eosinophils was investigated by bioassay in pooled extracts from turbinates of 20 patients after separation with heparin-binding gel electrophoresis. An enzyme-linked immunoassay was performed to detect the amount of RANTES-protein in the single twenty samples. Eosinophilic chemotactic activity could be detected in the heparin-binding fraction of pooled extracts from 20 patients with allergic rhinitis but not in the non-heparin-binding fraction. RANTES was identified in the heparin-binding fraction. Therefore it was detected in the twenty single extracts of turbinates in concentrations known to elicit significant biological activity in vitro resigns, ranged between 0.4 ng/mg tissue and 2.9 ng/mg tissue. Thus RANTES secretion in allergic rhinitis could be shown in a protein fraction with eosinophilic chemotactic activity and it suggest to be one reason for immigration of eosinophils in the nasal mucosa of patients with allergic rhinitis.