Seasonal modulation of the C-type lectin MGL on human DCs

Abstract

The C-type lectin MGL is a pathogen recognition receptor, expressed by dendritic cells (DCs) and macrophages (Ms), able to bind GalNAc (Tn)-carrying structures. This receptor also recognized Tn-TAAs that were internalized, processed and presented by DCs to T cells and it acted as an adjuvant on DCs, highlighting its possible application in anti-cancer vaccination. In this work, we found that this receptor present a seasonal modulation: its expression is higher in winter rather than in summer. The percentage of MGL + donors displayed a negative trend that dropped to 33% during the summer and increased up to 100% in winter. This modulation could be also ascribed to the circa-annual variation of glucocorticoids, in fact MGL is up-regulated in presence of dexamethasone in vitro. The seasonal variation of this receptor could be an important point in the field of tumor vaccination strategies.

MGL Receptor and Immunity: When the Ligand Can Make the Difference

“…In humans, monocyte-derived DCs express moderate MGL levels, which become negative after DC maturation. In addition variation of its expression related to seasonal changes is observed [ 42 ]. Moreover, MGL is upregulated on tolerogenic DCs generated in the presence of glucocorticoids and during chronic inflammatory conditions such as rheumatoid arthritis, implicating MGL in immune regulation [ 43 ].…”

Ligand Recognition by the Macrophage Galactose-Type C-Type Lectin: Self or Non-Self?—A Way to Trick the Host’s Immune System

“…MGL is most highly expressed on immature DCs (iDCs), monocyte-derived DCs (moDCs), CD1c+ DCs as their specific marker, and alternatively activated macrophages (subtype M2a), and its level may depend on various factors and the local microenvironment [14,[35][36][37][38][39]. Zizzari et al [39] found that the variation in MGL expression depends on seasonal changes with a negative trend that dropped to 33% during the summer and increased to 100% in winter. In turn, van Vliet et al [25] observed MGL upregulation on tolerogenic DCs in the presence of immunosuppressive dexamethasone and during chronic inflammatory conditions such as rheumatoid arthritis.…”