Supplementary data for: Ligand-specific tuning of CLEC10A signalling strength and dendritic cell responses through engagement of different GalNAc-containing glycan structures

C-type lectin receptors on dendritic cells shape immune responses to
pathogens and tumour cells through the specific recognition of glycans.
C-type lectin domain family 10 member A [CLEC10A; also known as macrophage
galactose-type lectin (MGL)] binds terminal N-Acetylgalactosamine (GalNAc)
residues, which are often highly exposed on tumours. Signalling through
this receptor increases interleukin-10 (IL-10) and tumour necrosis factor
alpha production by monocyte-derived dendritic cells (moDCs), which
promotes a T helper 2 (Th2) or type 1 regulatory T cell (Tr1) response.
Recently, several CLEC10A glycan ligands were identified that induce
distinct conformational changes in the CLEC10A carbohydrate-recognition
domain, but their ability to alter moDC function has not been thoroughly
explored. Here, we used CLEC10A ligand glycodendrimers to investigate the
transcriptional responses induced by the CLEC10A ligands previously
modelled, and determined how these transcriptional programs were
associated with the cellular moDC responses. The CLEC10A ligand dendrimers
varied in their affinity for CLEC10A and their capacity to increase IL-10
produced by moDCs. Although all glycodendrimers induced differential gene
expression, this was strongest for the Forssman antigen dendrimer. The
volcano plots and gene lists from this analysis are included in the
supporting data provided here. The gene ontology (GO) terms
associated with genes detected across ligands related to mitogen-activated
protein kinase (MAPK) signalling, chemotaxis, apoptosis, angiogenesis,
cytokine production and CD4+ T cell differentiation, as seen in the
supporting table 2. The CLEC10A ligand dendrimers also altered
the chemokine profile secreted by moDCs. Furthermore, these
glycodendrimers increased the percentage of C-C chemokine receptor type 7
(CCR7)-expressing moDCs, which was prevented by inhibiting CLEC10A
signalling. Overall, there was limited evidence for glycan-specific
signalling via CLEC10A, but the glycans did alter the magnitude of the
CLEC10A-mediated responses.