ved 3 February 2016; Revised 17 March 2016; Accepted 24 March 2016
Abstract
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 mannosebinding
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