Surfactant protein D binds genomic DNA and apoptotic cells, and enhances their clearance, in vivo.
Collectins, such as surfactant protein D (SP-D), bind apoptotic cells; however, the ligands that they recognize on these cells are unknown. We hypothesized that SP-D binds to the DNA present on these cells. We show that SP-D binds and aggregates mouse alveolar macrophage DNA effectively. Alveolar macrophages of SP-D((-/-)) mice contained more nicked DNA than those of SP-A((-/-)) and wild type mice. Our results also suggest that carbohydrate recognition domains of SP-D may recognize DNA present on the apoptotic cells. Therefore, cell-surface DNA could be a ligand for recognition of apoptotic cells by collectins.
Palaniyar
Nades
N
MRC Immunochemistry Unit, Department of Biochemistry, Oxford University, South Parks Road, Oxford, OX1 3QU, United Kingdom. Palaniyar.Nadesalingam@bioch.ox.ac.uk
Clark
Howard
H
Nadesalingam
Jeya
J
Hawgood
Samuel
S
Reid
Kenneth B M
KB
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001665:Binding Sites; D037222:Collectins / Q000378:metabolism*; D004247:DNA / Q000235:genetics* / Q000378:metabolism*; D005434:Flow Cytometry; D016678:Genome; D016676:Macrophages, Alveolar / Q000166:cytology / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D037663:Pulmonary Surfactant-Associated Protein D / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
D037222:Collectins; D037663:Pulmonary Surfactant-Associated Protein D; D004247:DNA