Lung surfactant proteins (SP-A and SP-D) in non-adaptive host responses to infection.
The lung surfactant proteins A and D (SP-A and SP-D) are collectins composed of C-type lectin domains attached to collagen regions. SP-A and SP-D are mainly found in the surfactant covering the pulmonary epithelial cells, but are also produced by cells lining the gastrointestinal tract. The main role of SP-A and SP-D is to interact directly with carbohydrate on the surface of microbial pathogens, thereby initiating a variety of effector mechanisms. This review focuses on the non-adaptive host responses of SP-A and SP-D to infection. Interaction of SP-A and SP-D with phagocytes is discussed and the structure and function of the putative receptors for SP-A and SP-D is presented. SP-A and SP-D seem to be regulated in a way similar to acute-phase proteins in the course of inflammation and evidence for the involvement of SP-A and SP-D as immunomodulators as well as their role in clearing allergens and modulating effector mechanisms in allergic reactions is discussed.
Holmskov
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Immunology and Microbiology, Institute of Medical Biology, University of Southern Denmark, Odense. holmskov@imbmed.sdu.dk
D000222:Adaptation, Physiological / Q000276:immunology; D000818:Animals; D002352:Carrier Proteins; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D018960:Hyaluronan Receptors; D006967:Hypersensitivity / Q000276:immunology; D007239:Infections / Q000276:immunology*; D008168:Lung / Q000276:immunology*; D008562:Membrane Glycoproteins; D024101:Mitochondrial Proteins; D011510:Proteolipids / Q000276:immunology*; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000276:immunology*; D011951:Receptors, Complement / Q000276:immunology
C087299:C1QBP protein, human; D002352:Carrier Proteins; D006023:Glycoproteins; D018960:Hyaluronan Receptors; D008562:Membrane Glycoproteins; D024101:Mitochondrial Proteins; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D011951:Receptors, Complement; C032402:complement 1q receptor