EARLY-TYPE HYPERSENSITIVITY-ASSOCIATED AIRWAY INFLAMMATION AND EOSINOPHILIA INDUCED BY DERMATOPHAGOIDES-FARINAE IN SENSITIZED MICE

In a murine ear swelling model, we demonstrated a unique hypersensitiv ity response and defined it as early-type hypersensitivity (ETH), ETH was characterized by increased vasopermeability and edematous change t hat occurred within 1 h at the site of Ag challenge, In this study, in tranasal challenge with Dermatophagoides farinae (Df) on Df-sensitized BALB/c mice induced an ETH response in the lungs, The lung ETH was ma nifested by an increase in wet lung weight, production of TNF-cu in br onchoalveolar lavage fluids, and hyperemia and edematous change around vessels of small airways 1 h after Ag provocation, The challenged ani mals subsequently developed airway inflammation, beginning with a neut rophilic infiltrate which was followed by lymphocytes and eosinophils, The Df-induced eosinophilia was Ag-specific and maximal at 48 h after challenge, At this time, the trachea from sensitized mice also exhibi ted hyperreactivity to carbachol, Pretreatment with anti-CD4(+) mAb si gnificantly decreased the recruitment of eosinophils in bronchoalveola r lavage fluids, An enhanced expression of pulmonary endothelial vascu lar cell adhesion molecule-1 was noted as early as 6 h after challenge , Anti-Df Abs of IgG class, but not IgE class, were detected in Df-imm unized mice at the time of challenge, Furthermore, Df challenge induce d a stronger eosinophil response in BALB/c mice (H-2(d)) than in B10.B R (H-2(k)) mice, B10.BR mice also did not exhibit pulmonary edema or E TH of ear swelling 1 h after challenge, These data suggest that an ETH -associated 1 h pulmonary edematous change was induced by intranasal c hallenge of Df in Df-sensitized mice, and that the ETH might contribut e to the development of the subsequent pulmonary inflammation and eosi nophilia.