Pulmonary collectins and innate host defense of the lung.
Surfactant proteins A and D (SP-A and SP-D) are members of the collectin family of polypeptides expressed in the respiratory tract that bind bacterial, fungal and viral pathogens, enhancing their opsonization and killing by phagocytic cells. Clearance of bacterial pathogens including group B streptococci, Haemophilus influenza, Pseudomonas aeruginosa and viral pathogens, respiratory syncytial virus, adenovirus and influenza A virus, was deficient in SP-A(-/-) mice. SP-A deficiency was associated with enhanced inflammation and synthesis of proinflammatory cytokines. SP-D(-/-) mice cleared these bacteria as efficiently as wild-type mice; however, clearance of viral pathogens was deficient in SP-D(-/-) mice and associated with increased inflammation. SP-A and SP-D play critical and distinct roles in the regulation of alveolar macrophage function and inflammation, contributing to innate defense of the lung.
Children's Hospital Medical Center, Division of Neonatology and Pulmonary Biology, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA.
A M
AM
LeVine
J A
JA
Whitsett
D000818:Animals; D001424:Bacterial Infections / Q000276:immunology; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007113:Immunity, Innate; D007249:Inflammation / Q000276:immunology; D008168:Lung / Q000276:immunology*; D051379:Mice; 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*; D014777:Virus Diseases / Q000276:immunology
D006023:Glycoproteins; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants