Authors: Zhang, Hongtao; Palma, Angelina S.; Zhang, Yibing; Childs, Robert A.; Liu, Yan; Mitchell, Daniel A.; Guidolin, Leticia Soledad; Weigel, Wilfried; Mulloy, Barbara; Ciocchini, Andres Eduardo; Feizi, Ten; Chai, Wengang
Publication Date: 2016.
The β1,2-glucans produced by bacteria are important in invasion, survival and immunomodulation in infected hosts be they mammals or plants. However, there has been a lack of information on proteins which recognize these molecules. This is partly due to the extremely limited availability of the sequence-defined oligosaccharides and derived probes for use in the study of their interactions. Here we have used the cyclic β1,2-glucan (CβG) of the bacterial pathogen Brucella abortus, after removal of succinyl side chains, to prepare linearized oligosaccharides which were used to generate microarrays. We describe optimized conditions for partial depolymerization of the cyclic glucan by acid hydrolysis and conversion of the β1,2-gluco-oligosaccharides, with degrees of polymerization 2-13, to neoglycolipids for the purpose of generating microarrays. By microarray analyses, we show that the C-type lectin receptor DC-SIGNR, like the closely related DC-SIGN we investigated earlier, binds to the β1,2-gluco-oligosaccharides, as does the soluble immune effector serum mannose-binding protein. Exploratory studies with DC-SIGN are suggestive of the recognition also of the intact CβG by this receptor. These findings open the way to unravelling mechanisms of immunomodulation mediated by β1,2-glucans in mammalian systems.
Author affiliation: Zhang, Hongtao. Imperial College London; Reino Unido. Jiangnan University; China
Author affiliation: Palma, Angelina S.. Imperial College London; Reino Unido. Universidade de Lisboa; Portugal
Author affiliation: Zhang, Yibing. Imperial College London; Reino Unido
Author affiliation: Childs, Robert A.. Imperial College London; Reino Unido
Author affiliation: Liu, Yan. Imperial College London; Reino Unido
Author affiliation: Mitchell, Daniel A.. University of Warwick; Reino Unido
Author affiliation: Guidolin, Leticia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Weigel, Wilfried. SCIENION AG; Alemania
Author affiliation: Mulloy, Barbara. Imperial College London; Reino Unido
Author affiliation: Ciocchini, Andres Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Feizi, Ten. Imperial College London; Reino Unido
Author affiliation: Chai, Wengang. Imperial College London; Reino Unido
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Publication Date: 2010.
Dendritic-cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN; CD209) has an important role in mediating adherence of Mycobacteria species, including M. tuberculosis and M. bovis BCG to human dendritic cells and macrophages, in which these bacteria can survive intracellularly. DC-SIGN is a C-type lectin, and interactions with mycobacterial cells are believed to occur via mannosylated structures on the mycobacterial surface. Recent studies suggest more varied modes of binding to multiple mycobacterial ligands. Here we identify, by affinity chromatography and mass-spectrometry, four novel ligands of M. bovis BCG that bind to DC-SIGN. The novel ligands are chaperone protein DnaK, 60 kDa chaperonin-1 (Cpn60.1), glyceraldehyde-3 phosphate dehydrogenase (GAPDH) and lipoprotein lprG. Other published work strongly suggests that these are on the cell surface. Of these ligands, lprG appears to bind DC-SIGN via typical proteinglycan interactions, but DnaK and Cpn60.1 binding do not show evidence of carbohydrate-dependent interactions. LprG was also identified as a ligand for DC-SIGNR (L-SIGN; CD299) and the M. tuberculosis orthologue of lprG has been found previously to interact with human toll-like receptor 2. Collectively, these findings offer new targets for combating mycobacterial adhesion and within-host survival, and reinforce the role of DCSIGN as an important host ligand in mycobacterial infection.
Instituto de Biotecnología
Author affiliation: Carroll, Maria V. University of Oxford. Department of Pharmacology; Gran Bretaña
Author affiliation: Sim, Robert B. University of Oxford. Department of Pharmacology; Gran Bretaña
Author affiliation: Bigi, Fabiana. INTA. Instituto de Biotecnología; Argentina
Author affiliation: Jäkel, Anne. University of Oxford. Department of Pharmacology; Gran Bretaña
Author affiliation: Antrobus, Robin. Addenbrooke’s Hospital. Cambridge Institute of Medical Research; Gran Bretaña
Author affiliation: Mitchell, Daniel A. University of Warwick. CSRI-UHCW Walsgrave Campus; Gran Bretaña
Repository: INTA Digital (INTA). Instituto Nacional de Tecnología Agropecuaria