Immunosuppressed surfactant protein A-deficient mice have increased susceptibility to Pneumocystis carinii infection.
Immunosuppressed Swiss Black mice deficient in surfactant protein A (SP-A(-/-)) and wild-type control mice (SP-A(+/+)) were exposed to Pneumocystis carinii by environmental exposure, intratracheal inoculation, and direct exposure to other infected animals. The frequency and intensity of P. carinii infection were significantly greater in the SP-A(-/-) mice by all 3 methods of exposure. P. carinii free of SP-A and alveolar macrophages were isolated from SP-A(-/-) mice and were tested in an in vitro attachment assay. Pretreatment of P. carinii with human SP-A resulted in a significant dose-dependent increase of the adherence of P. carinii to the macrophages. Thus, SP-A plays a role in host defense against P. carinii in vivo, perhaps by functioning as a nonimmune opsonin.
Research Service, Department of Veterans Affairs Medical Center, and Divisions of Infectious Diseases and Pulmonary/Critical Care Medicine, University of Cincinnati, Cincinnati, OH 45220, USA. Michael.Linke@med.va.gov
M J
MJ
Linke
C E
CE
Harris
T R
TR
Korfhagen
F X
FX
McCormack
A D
AD
Ashbaugh
P
P
Steele
J A
JA
Whitsett
P D
PD
Walzer
D000818:Animals; D001422:Bacterial Adhesion; D002478:Cells, Cultured; D004198:Disease Susceptibility; D004781:Environmental Exposure; D016867:Immunocompromised Host; D008168:Lung / Q000382:microbiology / Q000473:pathology; D016676:Macrophages, Alveolar / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D018345:Mice, Knockout; D011010:Pneumocystis / Q000166:cytology / Q000472:pathogenicity*; D011020:Pneumonia, Pneumocystis / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D011510:Proteolipids / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D014132:Trachea / Q000382:microbiology
D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants