Surfactant protein A-deficient mice are susceptible to group B streptococcal infection.
To determine the role of surfactant protein A (SP-A) in host defense, the murine SP-A locus was targeted by homologous recombination to produce mice lacking SP-A. SP-A -/- and control mice were infected with group B streptococcus (GBS) by intratracheal instillation. Pulmonary infiltration 6 and 24 h following infection was more severe in SP-A -/- than in control mice, and was associated with increased numbers of GBS in lung homogenates. Dissemination of GBS to the spleen was observed more frequently in SP-A -/- mice. Pulmonary infiltration with macrophages was similar in both groups; however, the number of bacteria associated with alveolar macrophages was decreased in the SP-A-deficient mice. There was no detectable compensatory increase in surfactant protein D, the other known pulmonary collectin, in response to GBS instillation. SP-A plays an important role in vivo, enhancing clearance of GBS from the lung and inhibiting systemic dissemination of the organism.
LeVine
A M
AM
Children's Hospital Medical Center, Division of Pulmonary Biology, Cincinnati, OH 45229, USA.
Bruno
M D
MD
Huelsman
K M
KM
Ross
G F
GF
Whitsett
J A
JA
Korfhagen
T R
TR
D000818:Animals; D005260:Female; D008168:Lung / Q000276:immunology / Q000473:pathology; D016676:Macrophages, Alveolar / Q000276:immunology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D018410:Pneumonia, Bacterial / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D011510:Proteolipids / Q000502:physiology*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000502:physiology*; D013154:Spleen / Q000382:microbiology; D013292:Streptococcus agalactiae / Q000276:immunology*
D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants