Lung surfactant proteins A and D in innate immune defense

The lung surfactant proteins (SP) A and D are large multimeric proteins and belong to a family of collagenous C-type lectins designated collectins, Bo th SP-A and SP-D are believed to play a role in the innate immunity of the lung, SP-A and SP-D bind to a broad spectrum of pathogens, including bacter ia, viruses, fungi and yeasts but also lipopolysaccharides and allergens. F urthermore, SP-A and SP-D enhance the clearing of various pathogens by neut rophils and macrophages in vitro. Recent in vivo studies on SP-A deficient mice also support a role of SP-A in host defense. Copyright (C) 2000 S. Kar ger AG, Basel.