Allergen-induced bronchial inflammation is associated with decreased levels of surfactant proteins A and D in a murine model of asthma.
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 p-stimulated intrapulmonary lymphocyte proliferation of naïve 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.


CONCLUSIONS
These results indicated the involvement of pulmonary surfactant proteins in the allergic bronchial inflammation of sensitized mice.
Wang
J Y
JY
Division of Clinical Immunology, Departments of Paediatrics, and Microbiology and Immunology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan, Republic of China. a122@mail.ncku.edu.tw
Shieh
C C
CC
Yu
C K
CK
Lei
H Y
HY
D000485:Allergens / Q000009:adverse effects*; D000818:Animals; D001249:Asthma / Q000378:metabolism*; D001985:Bronchial Provocation Tests; D001991:Bronchitis / Q000276:immunology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004391:Dust / Q000009:adverse effects; D006023:Glycoproteins / Q000494:pharmacology*; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008214:Lymphocytes / Q000187:drug effects; D051379:Mice; D008925:Mites / Q000276:immunology*; D011510:Proteolipids / Q000378:metabolism*; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000378:metabolism* / Q000494:pharmacology*
D000485:Allergens; D004391:Dust; D006023:Glycoproteins; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants