CD91 interacts with mannan-binding lectin (MBL) through the MBL-associated serine protease-binding site.
CD91 plays an important role in the scavenging of apoptotic material, possibly through binding to soluble pattern-recognition molecules. In this study, we investigated the interaction of CD91 with mannan-binding lectin (MBL), ficolins and lung surfactant proteins. Both MBL and L-ficolin were found to bind CD91. The MBL-CD91 interaction was time- and concentration-dependent and could be inhibited by known ligands of CD91. MBL-associated serine protease 3 (MASP-3) also inhibited binding between MBL and CD91, suggesting that the site of interaction is located at or near the MASP-MBL interaction site. This was confirmed by using MBL mutants deficient for MASP binding that were unable to interact with CD91. These findings demonstrate that MBL and L-ficolin interact with CD91, strongly suggesting that they have the potential to function as soluble recognition molecules for scavenging microbial and apoptotic material by CD91.
Department of Clinical Biochemistry and Immunology, Statens Serum Institut, Artillerivej 5, Copenhagen, Denmark. kds@ssi.dk
Karen
K
Duus
Nicole M
NM
Thielens
Monique
M
Lacroix
Pascale
P
Tacnet
Philippe
P
Frachet
Uffe
U
Holmskov
Gunnar
G
Houen
D019943:Amino Acid Substitution; D015703:Antigens, CD / Q000737:chemistry* / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D002118:Calcium / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D037102:Lectins / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D037601:Mannose-Binding Lectin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D050606:Mannose-Binding Protein-Associated Serine Proteases / Q000737:chemistry* / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020349:Surface Plasmon Resonance; D000097604:Ficolins
D015703:Antigens, CD; D002118:Calcium; D037102:Lectins; D008024:Ligands; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D037601:Mannose-Binding Lectin; D050606:Mannose-Binding Protein-Associated Serine Proteases; D050505:Mutant Proteins; D011994:Recombinant Proteins; D000097604:Ficolins; C475476:LRP1 protein, human; C445619:MBL2 protein, human; C084067:MASP1 protein, human