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

ABSTRACT

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.