Immune responses to tyrophagus putrescentiae-induced airway inflammation in mice.

BACKGROUND Storage mites are a source of aeroallergens that affect patients with allergic rhinitis and asthma. Tyrophagus putrescentiae is a causative factor of airway hypersensitivity, but the mechanisms and pathogenesis of Tputrescentiae-induced allergy are not well understood. OBJECTIVE This study aimed to develop a murine model of T putrescentiae-induced allergic asthma. METHODS Immune responses and physiologic variations in immunoglobulins (Ig), leukocyte subpopulations, cytokines, gene expression, pulmonary function, and lung pathology were evaluated after intraperitoneal sensitization and intratracheal challenge with crude extract of T putrescentiae. RESULTS After sensitization with aluminum hydroxide and challenge with T putrescentiae in mice, levels of T putrescentiae-specific IgE and IgG1 in sera increased significantly compared to the normal saline group (P < .01): Values for inflammatory leukocytes (neutrophils and eosinophils) and cytokines (interleukin [IL] 4, IL-5, and IL-13) increased significantly after sensitization. In terms of pulmonary function, pause values were significantly enhanced in T putrescentiae-sensitized mice after intratracheal challenge with T putrescentiae (P < .05). Expression of type 2 helper T cell (T(H)2)-related genes (IL4, IL5, IL13, and RANTES), T(H)2-specific transcription factor (GATA-3), and proinflammatory genes (IL6), and T(H)(H)17-related genes (IL17F) increased significantly after airway challenge. Sensitization with T putrescentiae crude extract led to inflammation of lung tissue, thickening of the tracheal wall, and tracheal rupture. CONCLUSIONS Intraperitoneal sensitization followed by intratracheal challenge with crude extract of T putrescentiae can induce airway inflammation in BALB/c mice. The symptoms observed in a mouse model of allergic asthma, in terms of immune and clinical parameters, are reminiscent of the symptoms of allergic asthma in humans. A mouse model can be used to evaluate the therapeutic effectiveness of drugs on T putrescentiae-induced airway inflammation in humans.