Background: Increasing evidence suggests that pulmonary surfactant protein A (SP-A) and D (SP-D) participate in the lung defence against pathogens. However, the role of surfactant proteins in the pathogenesis of allergen-induced airway inflammation has not been elucidated. In this study we examined the levels and distributions of SP-A and SP-D in a dust mite (Dermatophagoides pteronyssinus, Der p) allergen-induced murine model of asthma. Methods: The concentration of SP-A and SP-D in the bronchoalveolar lavage fluid (BALF) and the distribution of surfactant proteins in the lung were assayed by ELISA and immunohistochemistry methods, respectively. The effect of surfactant proteins on allergen-induced pulmonary lymphocyte proliferation was also studied. Results: We demonstrated that there were marked reductions of SP-A and SP-D levels in the BALF of Der p-sensitized BALB/c mice at 48-72 h after allergen challenge (AC). Both purified SP-A and SP-D were able to suppress, in a dose dependent manner, Der pstimulated intrapulmonary lymphocyte proliferation of nfl/ye mice with saline or allergen challenge, or of Der p-sensitized mice with saline challenge. On the contrary, this suppressive effect was mild (<9%) on lymphocytes from sensitized mice after AC. Conclusion: These results indicated the involvement of pulmonary surfactant proteins in the allergic bronchial inflammation of sensitized mice.
All Science Journal Classification (ASJC) codes
- Immunology and Allergy