Final Activity Report Summary - FUNCLER (Functional characterisation of NK and DC lectin receptors)
Dendritic cells (DC) play a key role in the immune system by sampling pathogens in the body tissues and interacting with other immune cells for developing an immune reaction. They have in their surface different proteins that allow them to recognise pathogens and communicate with other immune cells to generate a response. Some of these surface proteins recognise specific carbohydrate motifs and are known as lectin receptors. The objective of this action was the functional characterisation of new lectin receptors expressed in dendritic cells. This means the characterisation of the carbohydrate binding specificity, looking for possible pathogens that can bind these receptors, and identify possible ligand(s) in other cells of the immune system. The ultimate goal was, with all these data, to understand the function and the role of these receptors in the DC biology.
As result of this action the study of 4 lectins was initiated (DCIR, CLECSF8, MINCLE and DLEC) but later on was focused on DCIR. No pathogens or pathogenic products were found to bind to DCIR. Also no carbohydrate structures were found to bind DCIR. Concerning cell ligands, DCIR was found to bind monocytes suggesting the presence of a ligand for DCIR on these cells. Cell lines from different origin containing terminal galactose glycans on their surface also showed binding to DCIR. On the other hand monocytes lose the binding to DCIR very quickly when they differentiate to dendritic cells, in correlation to a lower expression of terminal galactose glycans in their surface. These data suggests a binding specificity of DCIR for terminal galactose glycans.
As result of this action the study of 4 lectins was initiated (DCIR, CLECSF8, MINCLE and DLEC) but later on was focused on DCIR. No pathogens or pathogenic products were found to bind to DCIR. Also no carbohydrate structures were found to bind DCIR. Concerning cell ligands, DCIR was found to bind monocytes suggesting the presence of a ligand for DCIR on these cells. Cell lines from different origin containing terminal galactose glycans on their surface also showed binding to DCIR. On the other hand monocytes lose the binding to DCIR very quickly when they differentiate to dendritic cells, in correlation to a lower expression of terminal galactose glycans in their surface. These data suggests a binding specificity of DCIR for terminal galactose glycans.