title: Surfactant protein D modulates pulmonary clearance of pollen starch granules.
abstract: Pollen starch granules (PSGs) are allergen particles that get into contact with pulmonary surfactant and phagocytes in the terminal airways. In this study, the effects of surfactant protein D (SP-D) on the interaction of PSGs with phagocytes and on the pulmonary clearance of PSGs were determined. Fluorescently labeled PSGs were incubated in vitro with murine lung macrophages or dendritic cells (DCs) ± recombinant rat SP-D (rrSP-D). In addition, the effect of SP-D on uptake of PSGs by lung macrophages and DCs was studied in vivo. Furthermore, PSGs were instilled in Balb/c mice and the effects of SP-D on total lung clearance were assessed by optical imaging. SP-D treatment increased the number of PSG-positive macrophages and DCs in vitro. Furthermore, SP-D accelerated uptake/binding by alveolar macrophages and reduced the number of PSG-positive tissue macrophages and DCs at 24 hours. However, SP-D did not affect total lung clearance of PSGs and it did not enhance the T-cell proliferation induced by PSG-positive DCs. In conclusion, SP-D increased PSG-positive cells in vitro and accelerated PSG binding/uptake in vivo. The observed effects were limited to cellular clearance mechanisms and did not affect the total clearance of PSGs from the lung.
authors.affiliation: Fraunhofer Institute of Toxicology and Experimental Medicine, Hannover, Germany.
authors.forename: Carla
authors.initials: C
authors.lastname: Winkler
authors.forename: Katja
authors.initials: K
authors.lastname: Hüper
authors.forename: Ann-Carina
authors.initials: AC
authors.lastname: Wedekind
authors.forename: Sabine
authors.initials: S
authors.lastname: Rochlitzer
authors.forename: Christina
authors.initials: C
authors.lastname: Hartwig
authors.forename: Meike
authors.initials: M
authors.lastname: Müller
authors.forename: Armin
authors.initials: A
authors.lastname: Braun
authors.forename: Norbert
authors.initials: N
authors.lastname: Krug
authors.forename: Jens M
authors.initials: JM
authors.lastname: Hohlfeld
authors.forename: Veit J
authors.initials: VJ
authors.lastname: Erpenbeck
mesh_terms: D000485:Allergens / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D008168:Lung / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D009079:Mucociliary Clearance / Q000187:drug effects*; D010587:Phagocytosis / Q000187:drug effects / Q000276:immunology; D011058:Pollen / Q000276:immunology / Q000378:metabolism*; D037663:Pulmonary Surfactant-Associated Protein D / Q000494:pharmacology*; D051381:Rats; D011994:Recombinant Proteins; D013213:Starch / Q000276:immunology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects
chemical_list: D000485:Allergens; D037663:Pulmonary Surfactant-Associated Protein D; D011994:Recombinant Proteins; D013213:Starch