Surfactant protein D binds genomic DNA and apoptotic cells, and enhances their clearance, in vivo
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Updated: Aug 25, 2026

Experimental Analysis of Apoptotic Thymocyte Engulfment by Macrophages
Published on: May 24, 2019
Nades Palaniyar1, Howard Clark, Jeya Nadesalingam
1MRC Immunochemistry Unit, Department of Biochemistry, Oxford University, South Parks Road, Oxford, OX1 3QU, United Kingdom. Palaniyar.Nadesalingam@bioch.ox.ac.uk
Abstract:
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.
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