Pathogen-associated carbohydrate moieties recognized by surfactant protein D (SP-D ligands)

Pathogen-associated carbohydrate moieties recognized by surfactant protein D (SP-D) represent a diverse class of microbial surface molecules, including lipopolysaccharides (LPS), lipoteichoic acids (LTA), and various terminal glycans. These moieties serve as pathogen-associated molecular patterns (PAMPs) that are specifically identified by the C-type lectin domain of SP-D, a key component of the innate immune system (Nayak et al., 2012, PMID: 22703241). Upon binding, SP-D facilitates the aggregation, opsonization, and subsequent clearance of pathogens such as bacteria, viruses, and fungi by alveolar macrophages (Watson et al., 2019, PMID: 31110321). In addition to direct antimicrobial activity, the interaction between SP-D and these carbohydrate targets modulates inflammatory signaling pathways, helping to maintain pulmonary homeostasis (Gardai et al., 2003, PMID: 14560035). Therapeutic strategies often involve the use of recombinant human SP-D or its fragments to target these moieties in conditions like neonatal respiratory distress syndrome, chronic obstructive pulmonary disease (COPD), and various respiratory infections (UniProt P35247).

Other names

SP-D ligandsPathogen-associated molecular patterns recognized by SP-DMicrobial surface glycansSurfactant protein D carbohydrate targets

Binding to terminal sugars (e.g., mannose, fucose, glucose) on pathogen surfaces via the C-terminal carbohydrate recognition domain (CRD) in a calcium-dependent manner, leading to pathogen neutralization and enhanced phagocytosis.