Surfactant protein C: its unique properties and emerging immunomodulatory role in the lung.
Surfactant protein C (SP-C) is a highly hydrophobic protein found in pulmonary surfactant. SP-C is synthesized exclusively in alveolar type II cells as a 21 kDa integral membrane precursor protein and subsequently proteolytically processed to a 3.7 kDa secretory protein. SP-C enhances the adsorption and spreading of phospholipids at the air-liquid interface thereby promoting the surface tension-lowering properties of surfactant. The importance of SP-C in normal lung function is underscored by the recent findings of inflammatory lung diseases associated both with absence of alveolar SP-C and with cellular expression of mutant SP-C isoforms. This review examines our current understanding of the role of SP-C in maintaining alveolar epithelial homeostasis and the potential role of abnormal SP-C expression in the development of lung diseases with particular emphasis on microbial pulmonary infection and inflammation.
Mulugeta
Surafel
S
Pulmonary and Critical Care Division, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4318, USA. mulugeta@mail.med.upenn.edu
Beers
Michael F
MF
D000818:Animals; D006801:Humans; D007155:Immunologic Factors / Q000235:genetics / Q000502:physiology*; D008168:Lung / Q000276:immunology*; D008171:Lung Diseases / Q000276:immunology; D008954:Models, Biological; D009154:Mutation; D037721:Pulmonary Surfactant-Associated Protein C / Q000235:genetics / Q000276:immunology*
D007155:Immunologic Factors; D037721:Pulmonary Surfactant-Associated Protein C