Surfactant protein D increases phagocytosis and aggregation of pollen-allergen starch granules.
Recent studies have shown that surfactant components, in particular the collectins surfactant protein (SP)-A and -D, modulate the phagocytosis of various pathogens by alveolar macrophages. This interaction might be important not only for the elimination of pathogens but also for the elimination of inhaled allergens and might explain anti-inflammatory effects of SP-A and SP-D in allergic airway inflammation. We investigated the effect of surfactant components on the phagocytosis of allergen-containing pollen starch granules (PSG) by alveolar macrophages. PSG were isolated from Dactylis glomerata or Phleum pratense, two common grass pollen allergens, and incubated with either rat or human alveolar macrophages in the presence of recombinant human SP-A, SP-A purified from patients suffering from alveolar proteinosis, a recombinant fragment of human SP-D, dodecameric recombinant rat SP-D, or the commercially available surfactant preparations Curosurf and Alveofact. Dodecameric rat recombinant SP-D enhanced binding and phagocytosis of the PSG by alveolar macrophages, whereas the recombinant fragment of human SP-D, SP-A, or the surfactant lipid preparations had no effect. In addition, recombinant rat SP-D bound to the surface of the PSG and induced aggregation. Binding, aggregation, and enhancement of phagocytosis by recombinant rat SP-D was completely blocked by EDTA and inhibited by d-maltose and to a lesser extent by d-galactose, indicating the involvement of the carbohydrate recognition domain of SP-D in these functions. The modulation of allergen phagocytosis by SP-D might play an important role in allergen clearance from the lung and thereby modulate the allergic inflammation of asthma.
Erpenbeck
Veit J
VJ
Fraunhofer Institute of Toxicology and Experimental Medicine, Nikolai-Fuchs-Str. 1a, 30625 Hannover, Germany. erpenbeck@item.fraunhofer.de
Malherbe
Delphine C
DC
Sommer
Stefanie
S
Schmiedl
Andreas
A
Steinhilber
Wolfram
W
Ghio
Andrew J
AJ
Krug
Norbert
N
Wright
Jo Rae
JR
Hohlfeld
Jens M
JM
D000485:Allergens / Q000378:metabolism*; D000818:Animals; D001688:Biological Products; D002417:Cattle; D002614:Chelating Agents / Q000494:pharmacology; D031745:Dactylis / Q000276:immunology; D004492:Edetic Acid / Q000494:pharmacology; D005690:Galactose / Q000494:pharmacology; D006801:Humans; D008055:Lipids; D016676:Macrophages, Alveolar / Q000276:immunology / Q000378:metabolism; D008320:Maltose / Q000494:pharmacology; D010587:Phagocytosis / Q000187:drug effects / Q000276:immunology*; D031784:Phleum / Q000276:immunology; D010743:Phospholipids; D011058:Pollen / Q000276:immunology / Q000378:metabolism; D037662:Pulmonary Surfactant-Associated Protein A / Q000494:pharmacology; D037663:Pulmonary Surfactant-Associated Protein D / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013213:Starch / Q000276:immunology / Q000378:metabolism
D000485:Allergens; D001688:Biological Products; D002614:Chelating Agents; D008055:Lipids; D010743:Phospholipids; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D011994:Recombinant Proteins; C078272:SF-RI 1, bovine surfactant preparation; D008320:Maltose; D013213:Starch; D004492:Edetic Acid; C068291:poractant alfa; D005690:Galactose