Hypersensitivity reactions in mouse airways after a single and a repeated hapten challenge

Objective and design In this study, we examined the effect of a single and a repeated hapten-challenge on inflammatory processes in the airways of mice undergoing a hapten-induced non-IgE mediated hypersensitivity reaction. Methods BALB/c mice were skin-sensitized with the hapten dinitroflourobenzene (DNFB) and intra-airway challenged with dinitrobenzene sulphonic acid (DNS). Mucosal exudation, tracheal vascular permeability, cellular accumulation, and serum murine mast cell protease (MMCP) were investigated at different time points after the first DNS-challenge and 30 min after a repeated DNS-challenge. Results MMCP levels in serum were increased at all time points after single challenge and repeated challenge. Increased vascular permeability as determined by Monastral blue staining, was found in the trachea of DNFB-sensitized mice after single DNS-challenge. A second exposure to DNS profoundly enhanced the Monastral blue labeling of the tracheal blood vessels of DNFB-sensitized mice. Furthermore, increased mucosal exudation and polymorphonuclear cell (PMN) accumulation were present in DNFB-sensitized mice compared to vehicle-sensitized animals after the first DNS challenge. Conclusions Increased mucosal exudation, vascular permeability, and PMN accumulation are prominent inflammatory features of the DNFB-induced hypersensitivity reaction in the airways. Furthermore, mast cell activation is associated with this hapten-induced hypersensitivity reaction.